If you would like to book a consultation with me you can do so here - www.reallifearchitecture.co.uk/online-services Please read the terms and conditions before you book.
PLEASE READ BEFORE POSTING! There are a lot of points being repeated in the comments, so for clarity; 1. I didn't use solar in this video because everyone's roof geometry and location are different. I will be investigating solar in the future as battery + solar PV is probably the most effective system. 2. An off-peak tariff would charge my EV for less without needing to install a battery but since my wife and I both work from home, the more expensive daytime tariff reduces the overall savings. 3. I checked the price of supply and installation with several vendors, some may disagree with the figures in the video but they were as accurate as I could get at the time. 4. Since making the video it seems off-peak tariffs are being phased out or the savings massively reduced. 5. I did not account for the daily standing charge in my calculations, my apologies. 6. Air-to-air heating is probably more efficent than air-to-water but is not widely used in the UK. 7. bidirectional charging, also known as vehicle-to-grid, is on its way and may make stand-alone batteries less relevant- see this video ua-cam.com/video/Re3QkHhuG1c/v-deo.html 8. A storage battery should only discharge about 80% of its capacity in normal operating conditions. This will preserve the life of the battery and most will last 10+ years. 9. The efficiency of the ASHP noted in the video is optimistic and probably only achievable during mild weather.
A well insulated & ventilated building will reduce the energy required to heat or cool a building to the extent that the method of heating is irrelevant
Thank you for clarifying the solar question - as I was sitting here thinking - if only he had solar to top up the batteries during the day, and thus offset how much draw down he has from the batteries in daylight hours - or you can extend how long the batteries hold up. A friend of mine uses combinations of batteries and solar - in the summer months he is completely off grid, and in the winter he has to use the grid either during the night, or to top up on the really dull days - his bills are incredibly low. And he runs his electric car via this set up more or less at nil cost to fill it up.
You should also check out a solar boiler, the hot tank goes before my HR boiler, for at least half the year I'm not using any gas for heating shower/tap water. I got it at the same time as an air heat pump which supports the gas hr boiler home heating. Previously I'd already got loft/floor/cavity insulation and solar panels. The Solar boiler/heatpump/HR boiler combi reduced my total electricity/gas bill from €2000 to €1000 The cost was €12.000 minus €4.000 subsidie. That was an 8 year pay back before the prices went sky high.
@real life architecht do the givenergy systems also have backup function in case of power outage? I see also in the sales blurb it says it sits alongside an inverter, so this is not the full package?? so far from what I have seen only tesla and sonnen are offering the package that does the lot. For what it's worth I think all of them are also being too clever for their own good by having their systems governed by monitoring from a cloud/database that can be "outaged" or hacked from a security perspective.I would be happier with a mechanical relay to govern mains/backup supply and a local timer of some sort to govern top-up from the grid if the battery needs it. It's already known that some folks hostile to us have been targetting core infrastructure via cyber,so the less connections the better.
@@bigmacntings7451 Fairpoint - my solar system in my campervan uses an inverter with three types on input - solar, mains and the vehicle alternator - with a leisure battery back up - all together they successfully manage a 12v fridge, lighting and charge my devices, even on the darkest days of the UK year.
Nice and succinct video. I have very similar scenario. One other consideration: If you expand storage, then you can power the Air/Ground Source Heat Pump at the much cheaper Tarrif also. However, one omission: you need to 'set aside' a proportion of the savings, as storage solution(s) won't last for ever. Totally agree the storage is the logical step, especially after going E.V. Hopefully the 'Heat pumps' will get better efficiency with new Motor tech etc. and Storage will get more economic too.
As someone that fits both various types of heating systems and battery storage, Battery Storage before Heat Pumps every time. There are the factors you've stated but beyond that which people often aren't informed of or don't think about is decorating after an ASHP installation, the hidden costs so to speak. With Battery Storage and solar it's generally minimal distruption and doesn't effect decor to the same degree as fitting larger radiators (if possible), having the floors up to run correctly sized pipes (if within budget) and although we will make good on our company we can't match in the decor or guarantee the floors especially if they're laminate coverings etc will come up without damage. Also Air-to-Air heat pump systems are far more efficient than the water based ones due to the temperature delta being 15 instead of 45. Generally though if a Gas appliance is pre 2001 (non-condensing) Solar + Battery or even just battery on its own and swapping tariff will often save more money than a heat pump. The easiest thing you can try is running the current system flow temp at 55c or below to see if the property maintains temperature. If it doesn't don't swap, get more insulation and consider the battery storage, they'll make a bigger impact in the majority of cases.
Interesting comment regarding air to air heat pumps being more efficient than air to water. I wonder why they aren't more popular in the uk? Compared to the US!
@@TC-V8 A multitude of reasons, floor void size being a major one. The expense of changing systems entirely being the second for existing properties. Most existing properties would need smaller diameter tubing back to a central location basically a Zender setup (seems to be the most well known in the states currently). For new builds it's a no brainer but the government doesn't want an increased summer load on the grid so there's no VAT exemptions or insentives, the mere fact if homes were built to Enerfit or Passive standards that the loading during the year would be minimal regardless doesn't come into it. As such our building practices haven't really changed since the 1930s with only slightly thicker cavity walls for slightly thicker insulation, even that hasn't increased substantially since the 1990s though.
@@TC-V8 psychological reason is that people are used to having water circulating around radiators. If I understand correctly (and please tell me if I have got this wrong) an air to air heat pump has pipework containing some fluid that's essentially a refrigerant running to every room and a condenser unit everywhere you want heat. That may be cost effective but it's not what people are used to.
@@effervescence5664 Also consider that even with an average COP of 3.5 over the year, gas is 3.5 times cheaper than electricity, currently People typically aren't going to shell out for an ASHP if there's no real payback period. That, and in older homes, the COP might be just 2.5 which means that it would cost even more to run Suddenly, ASHP doesn't seem like a decent idea. I'm allowed to get a maximum of 16 panels on my house, which should mean that I can run self sufficiently through electricity at least, and the remainder is energy that I could store in batteries for an ASHP The government is pushing ASHPs before they've pushed solar panels + batteries
Nice straightforward presentation of the facts. There is one limitation I have recently become aware of the maximum supply rate to a house has a limit unless you have the main supply upgraded. This places a limit on how much most people can download during the off peak rate period. Worth including in your calculations. 👌👍
Pretty bang-on with the calculations. I'll add a few points I think might be useful to know for people (I'm ASHP+Solar+battery owner): - When replacing an older boiler like oil-fired, biomass or gas backboiler, your ROI might be sooner. We replaced a backboiler which was on it's last legs anyway & 20% less efficient than todays condensers, so overall our running cost is about the same or slightly cheaper now. A condender system boiled would have been 3k+ anyway. - On an EV tariff which doesn't strictly require an EV, you can auto-program your ASHP thermostat to pump as much heat into your building as possible in the cheap hours, whereas you don't have a cheap gas window. If you want to do this, look into adding a buffer tank to your ASHP install too for a bit of extra thermal storage. - EV tariffs are a double-edged sword, and only really become cheaper if you have Solar to supplement the expensive day-electricity. Otherwise your day cost will most likely outweigh your night cost, unless you have an EV to charge. - If you do have an EV AND and heat pump AND a battery and you want all those things to charge in the cheap tarriff window, and you might have a tumble drier & pool heater if you're posh, you might need 3-phase depending on what your EV charging rate is. - ASHP install will need to be part of an unvented, mains pressure system. If your house is currently gravity-tanked, you need to add the system upgrade into the cost. Mains pressure showers are so worth it, and the hot/cold pressure being balanced is amazing. - ASHP will drain the battery very quickly, depending on what it's doing. For easy maths, a 10kwh battery will be drained in about 4 hours when maintaining heat in a 4-bed average UK house with other things on. When it comes to battery, my belief is go big or dont bother. 16kwh+, you really want to to last 24 hours if possible. And have more than 16a charging capability so it can be charged full in under 4 hours in the cheap EV tariff window. - I think ASHP + battery + solar is the full package where it all starts to make sense and be greater than the sum of the parts. Otherwise, your returns might be slower/never happen.
One point with that lessens the benefit of your suggestion to run the ASHP in the cheap time slot which is going to be at night. That's when outside temperature is likely to be lower, is not lowest, so you are driving the ASHP at its least efficient. If you've already paid for the ASHP yeah, use it. If it's not yet installed then do the comparison vs using resistive heating (dearer to run but bobbins to install) and vs using traditional electric storage heaters (that stored the energy as heat). It's not obvious to me which would be better. It seems fairly obvious that no one mix is best for all cases
@@trueriver1950 The real world difference in efficiency with ambiend temp difference of 10c is quite small, maybe around 20%. But the electricity rate is about 4x cheaper, so it makes sense to use that time window to it's maximum. Resistive heating would be much much cheaper to install (and heat pumps need an annual service ideally), but a few years down the line ashp will be winning. Actually, in January 2022 our ashp broke down and we were forced to used in-tank immersion heater for hot water and 3 oil radiators, 2 resistive space heaters & a halogen heater for around 3 weeks. The house was still cold & our electricity bill was around £270 at 18p/kwh Jan prices. That's around 2.5x as much as with the heat pump & a toasty house.
Author is using the most optimistic figure for airsource heatpump efficiency, you will only get 3.5Kw for every 1 Kw used by heatpump in the summer at 25deg C ambient or higher ( when you need the heating least ) - but in winter at >10 deg C you will get nearer 1.5Kw of heat for every 1Kw of power into the heatpump - this makes the battery even more attractive, and much less disruption to you house.
Hi, very interesting analysis however you calculations seem a little bit off. You refer to the running cost of you EV as a saving, however that night time saving to charge your car would be there even if you choose to do nothing other than set the car to charge overnight, so really shouldn’t form part of the overall calculation when talking about battery installation. How on earth can you say that the night time tariff isn’t worth using unless you install a battery that’s totally wrong as your main saving is in charging the car and not the battery. Your costings have to be base only on Charging the battery with cheap rate electricity and under those circumstances the payback period would be much longer. Just one other point people always talk about payback, I believe there’s more to it than that, it’s also about burning less dinosaur juice and the fact that having fitted a battery, solar system, and heat pump one’s house goes up in value. The investment isn’t lost just parked until sale time.
I agree with poster wobby, the comparison would have been clearer if you had left the car out of the calculations. It's comparing apples with oranges; the heat pump has no impact on the car. It makes the comparison a bit muddied, and harder to contemplate for those without EVs. As you're using so much power to charge the car would it not have been worth switching to flex rate electricity and charging car overnight anyway even without a house battery? Thanks for the eye opening vid anyhow!
Regardless of the financials a heat pump is only a boon if it is well designed & works effectively & efficiently and can get your house up to a comfortable level of warmth in winter. Not all installs will deliver that outcome.
several factors come into play. the guilbility of the buyer the mortgage of the seller the quality of the equipment the build of the house and insulation the quality of the design the quality of the installation for the vast majority of UK housing stock only 3 words make real financial sense insulation, insulation, insulation . Stopping heat transfer is the most energy efficient thing anyone can do.
Love the fact that you provided very detailed numbers, in terms of kWh instead of just costs (which are too variable these days). I have a few questions regarding your battery savings: 1. Did you factor in the round trip efficiency of lithium batteries? - My understanding is that it is about 95% for DC to DC, i dont know if there is more losses converting between AC 2. Did you factor in depth of discharge? Typically doing a 100% discharge each day is pretty stressful on a battery, even lithium. And will typically drastically shorten lifespan (based on mobile phone wear atleast)
@@basildza The author is using the most optimistic figure for airsource heatpump efficiency, you will only get 3.5Kw for every 1 Kw used by heatpump in the summer at 25deg C ambient or higher ( when you need the heating least ) - but in winter at >10 deg C you will get nearer 1.5Kw of heat for every 1Kw of power into the heatpump - this makes the battery even more attractive, and much less disruption to you house.
@@basildza That's OK, just pointing out the massive miscalculation of the article on heatpump expected output as well. which makes the slight error in battery look small compared. The truth is that heatpumps efficiency drops massively in colder weather, something the makers and the government are not keen to tell people.
Neil: Your analysis illustrates the 'problem' with heat pumps that not everyone understands: the difference in gas and electricity prices (while it remains) does not make heat pumps significantly cheaper to run than gas boilers - never mind the considerable up-front cost, which is why I think gov't grants for heat pumps are crazy when that money should be use to improve insulation. Furthermore, the reported dearth in heat pump engineers may (?) mean that the annual service to keep them running efficiently is rather more expensive than for gas boilers - something that no-one ever mentions when I read articles about HP use. For a start, if affixed up a wall, requiring a ladder to access, that, apparently, immediately adds to servicing cost of some £30-£50! Would you know what an average annual service costs? I bet it's more than for gas... I take your helpful point about battery storage. Perhaps there's one caveat: that as more people charge EVs using night-time rates, as well as for battery storage, will that cost difference reduce over time? Much like gov't incentives to buy EVs have all but disappeared now that more have them, will 'night-rate' elecy go the same way? I guess we can only speculate... Thanks for your useful analysis. I have solar but no EV. As a lower elecy user storage makes no sense for me given the payback time. An EV would likely change that. Perhaps one should add (the obvious?) that so far as I read, while solar/battery is not now thought to damage property sale price, the investment is not thought to enhance it much either (as an architect you may know more, but estate agents venture this opinion), such that if there's a reasonable prospect of a move in the next several years or more, that should cause pause, albeit that as elecy prices increase the advantage of money-saving tech will be more attractive to potential buyers.
I always thought thr heat pumps were an expensive waste of time, I would like to get off gas and use storage batteries but then I need to convert my combi boiler. It's a huge nightmare, not sure what is best to do, at the moment I plan to not turn the heating on at all, I'm not paying £500 a month
Also a self employed ARB architect (I resigned from RIBA after 30 year membership in disgust at what has happened to the Institution). The coefficient of performance you quote at 3.5 for the ASHP is EXTREMELY optimistic, even as a maximum value, and would only ever apply when it is warmer outside than the latent temperature inside. When it is colder outside, there is literally no heat to be gained from the environment and you are working 'compressor only' and therefore have very expensive electric heating. ASHP in the UK are 'economic' for very short periods in spring and autumn. Also, just like the former 'green new deal', government funding is only available by using 'approved installers' who's costs are higher than non-approved installers, so once again the apparent subsidy is enjoyed more by the installer than the consumer. 'Payback' for ASHP installation is likely to be beyond the useful life of the equipment. The significantly larger radiators required lose wall space. I have recently reluctantly facilitated a whole house refurbishment with ASHP, but only on the basis of UFH at both levels (and my thoughts on UFH on a timber suspended first floor are from bitter experience still cautious despite using what at first reports seems to be a good product from Celecta) and solar electricity generation and battery storage to feed the compressor. All in, the changes to the floors, the ASHP and the solar with battery have added some £45k to the project which I fear will never be offset in use. Edit: I nearly forgot; with two rapid EV charging points along with the ASHP, Western Power determined the property needed to be upgraded to 3 phase which meant pulling in a new cable up the drive!
Thank you for sharing. I am now loosing patience with clients wanting to explore ASHP options, wasting time until the penny drops that it’s a deeply flawed technology. Its only use is in new builds, at least until the price drops substantially and people can use one with a gas boiler as a backup
Very valid point about the SCOP rating being optimistic. My Mitsubishi Ecodan 11.2kw is rated at around 3.34 and higher. Real world is nowhere near that. Closer to around 2.5 throughout the year. Really depends how much water you're heating, as this temp differential is what hurts the overall efficiency stats massively. The best COP numbers happen at very small ambient/indoor temp differences - which are times when heating isn't really necessary, late spring & mid autumn. These are what make the averages look better.
My friend is an architect and now seems to want to work abroad all the time. His family and I dont really see him as much now but he did mention RIBA being a factor this year. Why is it so badnow? Whathas changed? Cheers n stuff Leigh
A bit of misinformation on ASHP - this is not correct; one fact though is that UK "Approved installers" are charging over the top amounts, ASHP's in the UK are overpriced and are indeed barely worth it due to the suppliers and installers abusing the UK people. Outside of the UK however, ASHP are not a deeply flawed technology. My mini split (Still an air source heat pump, same tech) has a real world SCOP of 4.9 at 15c and is still well above 3 even at -5 degrees. The tech isn't flawed, UK businesses making record high profits on what I can only describe as mediocre installs is.
We've had 10kwh of batteries since April, based on their discharge readings they've saved us about £600 so about £100 per month. That does include some charging from solar but it's mostly overnight. Total cost of the system was about 11k so it's returning about 10% per year but I think if we'd just got the batteries we'd still get most of the saving
I think you ought to have included a 3rd scenario here which is installing the heat pump but switching to the dual rate electricty. You still get that 1000 saving on the car, even without the a battery. If you install a water cylinder large enough for a day's usage then it can be heated on cheap rate overnight. Your home is well insulated so you could at heat it up overnight on cheap rate (using the last few hours probably best) and lower the temp during the day when it's less cold outside anyway. You'll probably have to use some heating between sunset and cheap rate starting up but this could be kept to a minimum. Most of the year you probably won't need much peak rate heating except when it's very cold. Your water heating could be on cheap rate all year. Depending on how much other electricity you use during the day and what time your cheap rate starts etc I would expect that you would save money overall by switching to dual rate, especially given the huge savings charging your 2 cars.
I was wondering exactly the same thing. The £1000 on the car would seem to be the clincher. One thing I was wondering though - as an ASHP uses heat from the air, that external air temperature will be colder overnight, so the heat pump will have to work harder than it would during the day, to heat a given quantity of water to the same temperature. Does that temperature difference offset the savings of running the ASHP in the cheap rate period?
@@davidy7004 how much difference it makes depends on how hot you are having the water temp, as it is the difference between the air temp and water temp that is key. If your hot water is going to be 65 and your flow temp to get that is 70, then if your air temp changes between 15 and 5 then that would be either 55 or 65C difference. So night time is 18% bigger temp rise in that scenario. I think energy usage is a bit worse than linear so maybe it's 25% more electricity. But the night price was less than half the single rate price so it's still much cheaper. The problem with switching to dual rate is that it makes the day price higher than when you are on single rate so you have to watch out for that, especially if your heating is electric.
Thinking about it tho, for just hot water it would be more efficient to just install the hot water cylinder and heat it with an immersion heating element during the "low cost period" and not bother with the heat pump. From the research Iv'e looked into, the next step up is a "Zero Emission Boiler" as the way forward. They are basically a big thermal battery' with much higher energy density than just heating the water directly. You charge up with an electrical heating element and then use to heat you water on demand like a conventional boiler. So the same principle as charging at night and consuming in the day.
You also have to consider the fire hazard a battery holds. If it malfunctions and starts a thermal runaway youll have a hard time stopping it and depending on the position its been installed a 30/60min firewall wont hold it back
Good video, I'm am electrician and engineer who lives in Finland and has a ground source heat pump with underfloor heating. As you might imagine we have very cold and long winters. My house is 205m2 and we only use about 12000kwh per year. That's everything, heating, cooking, cleaning and lighting. The main thing what has to change in the UK is the insulation levels of houses. Given your average temperatures there is no way it is necessary that you should be using that much energy to heat that size of a home.. my home is also 20 years old. Also one thing to consider with batteries is their life span. They will most likely need replacing after 10 years. This of course depends on the battery type and conditions, charging controller etc
Lifepo4 batteries are generally rated at 10 years if you completely discharge them every day. If you only run them down to 80% then the charge life will double, and then you're into death by calendar date rather than by battery life.
one thing to consider is future expectation of prices. Gas is supposed to significantly increase this year and medium term may tilt things towards ASHP. Also if you had a battery too - your ASHP can benefit from the cheap rate (although you’d need a big battery..)
@@RealLifeArchitecture Do you think ASHP will actually drop in price though? Unlike solar, where panels keep getting more efficient and material costs per kWh keep coming down. Most of ASHP cost seems to be in the installation, which is a service and typically only goes up. And running costs is limited by physics and will stay proportional to the price of energy.
I like your videos, but in the real world, pensioners like me who live in an ex council house, over 120yrs old, don't "heat our homes", we heat a room that we are in , usually the living room. The rest of the house is freezing and getting covered in mould. We compensate for this by walking around the house like a polar explorer, during the winter months, dreaming of the coming summer, when it gets so hot we think we are going to die of heat stroke, because buying an air conditioner is a dream too far. I am looking at this video, because my gas boiler has given up the ghost, and I am looking for a solution to my "no hot water situation" It looks like I will be going for the more local electric heating, such as instant electric shower, and similar hand wash instant water boilers over the sink, and perhaps a portable small electric radiator, upstairs, and one for downstairs. So much for being self employed for over 50yrs, and never claimed any so called "benefits" in my whole life. If anyone reading this is considering self employment, think again, do yourself a big favour and go to work for a large company, with all the perks .
Thank you for this analysis. I have storage batteries and am very close to off grid full time. You touched on a very important point. Let me explain. I do everything I can to control when I purchase energy from my utility. For example, most of my power tools are battery operated, this allows me to charge batteries when the sun is out or off peak times when energy is cheaper or my house batteries are full, just like you do with your EV. My EV charges during the day, again when the sun is out or in your case at night off peak. My vacuum cleaner is a battery operated robotic vacuum that runs when we need to clean but what's important is that I CONTROL when to charge it. What you want to do ideally is be able to control when you use energy. Our water heater is tankless, this might raise some eyebrows but, again, I control when to use hot water. All our small usage like hand a dish washing doesn't tax the PV even though the tankless is wired for 20kW. You only use that amount of energy when it's at full house flow rate, several people showering, washing machines going etc. At our shower rate of 1.5 gpm it only uses ~5kWh which the batteries can cover. If we shower when the sun is out the PV covers the requirements of the tankless, off hours , no sun the batteries do. You would think that 5kWh is a lot for the batteries but it's not. Here's why: I take 4 or 5 minute showers which is about average for people but let's say I took an 8 minute shower. 8/60 x 5kWh = 666 watts to take a shower. That's easy for the batteries and inverters to cover. If we had a HPWH then we couldn't control when it heated water so it would cost more in the end, worse there are standby and line losses that don't occur with tankless. I heat the house water to ~40C a HPWH heats water to 49C or more, that's wasted energy. You get the idea, that's what you're basically doing with your EV, you are controlling when you use energy - this is the key to savings.
Most would be better using a point of source heater at the sink. Otherwise you use half a bowl of hot water just heating the pipes before any useful hot comes through. Or even more simple, boil a kettle
@@markthomasson5077 You can't shower with a kettle very well. What you're talking about are line losses. Tanks have two types of losses, standby and line. Standby in tanked heaters is how much the temp drops relative to the room. Line losses are from the tank to the fixture. The simple solution to line losses is lower volume lines, I use 3/8" insulated Pex to my fixtures so the line losses are almost null. On a tanked heater the water must have a minimum temp of 120°F(49°C) but even at those temps legionella still grows that's why commercial installations must run 140°F(60°C). There are great standby and line losses at those temps then you have to take that high temp and mix it down to usable. With something like a tankless you set your temp to the working temp so the line differential is much less and there are no mixing losses so unless you have a very long run there are minimal losses from the tankless to the fixtures. A 25' foot run with 3/8" Pex is only a cup or so of water so it's moot to have POI at every fixture. I run 105°F (~40°C) to my shower and since there is no tank for warm water to sit in no bacteria problems. If you have a big hot water demand HPWH is better but for a one to three person house tankless works out better. My one to two person house uses less than $5 a month at our grid rates running tankless. This high load tankless is a myth,. unless several people are showering at the same time you're using very little energy. A five minute shower at a load of 5kWh is only 5/60 x 5e3 = 417 watts then the water stops and no current is drawn. Hard to beat if you ask me. I monitored my heat and mini split for a month. I used 31kWh for hot water and 270kWh to heat the great room (25'x25'x14') from the middle of Nov. to the middle of Dec. that's $27 to heat and $3.10 for hot water. The PV covered both. If the outside temps rise to over 40°F (4.5°C) the mini covers the whole house, on really cold nights around 15°F(-9.5°C) and below I light a fire in my high efficiency fire place and with the mini I'm good.
This is just the explanation I was looking for as I've been considering these as well. It would be useful to know what difference solar panels would make, as I have them fitted already, and considering adding more.
It's sad but true that the consumer comparison is so often "how much money will I save" and not "how much carbon emission will I save", whereas the government funding is looking at the wider social cost of the carbon emissions. That said, I would definitely do the solar + battery as the first stage - possibly over-speccing the battery to help keep the cost down when you do the second stage and install the heat pump.
Hi Neil, Did you check out air to air heat pumps. You can get a 2.5 kW one for about £600. They are simple to install.I guess installation would be about £600. You could then run it at night To provide a Minimum temperature says 16°. I know this would be forced air so unless the building was moderately air tight , you might lose quite a lot. The added benefit would obviously be air-conditioning in the summer. I have installed these myself to anyway you Cant put a gas boiler.
Really interesting comparison. I've got battery storage, 2x Givenergy 8.2KwH = 16.4, with 5.6Kw of PV panels on the roof. Total installation cost 2 years ago was £12k. Also have an electric car that either gets charged from the solar generation or overnight on Economy 7. Only drawback with the system so far is that the inverter has a max input/output of 2.5Kw. However, I believe the latest inverter from Givenergy can do 3.5Kw. Perhaps you should add PV panels to your comparison? Did you consider a ground source heat pump?
I love the fact people worry about the payback period. When we renewed our kitchen in our last house the question of a payback period never came up because we did it to suit us. If you can afford to stop burning gas, coal, oil or whatever then do it. If you use a lot of electricity then a battery makes perfect sense especially as an EV owner plus you can now get EV tariffs and charge the car and battery at 7.5p per Kwh. .
Unfortunately money matters to most people. Renewable tech only gets going once cost/benefit gets to a certain point. It did this with wind and solar, it’s getting close with batteries.
Thank you for such a concise professionally detailed and edited video with visual price explanation (Genius). On Top of your 8.2kWh system saving ‘your’ systems £1,428 a year (with a break even of 3.47 yrs, you would also save a further £9,390 for the first 10 years or £23,770 for the first 20 years, after payback/breakeven or factoring in any future price increases. If you have solar and end up generating excess energy, saving this to your battery far out-ways any pay-in tariff and makes this figures even greater. PS There would potentially be some battery degregation over time. WELL DONE
Battery degradation may be an issue over the very long term, for sure. Adding solar to the mix would be interesting but I opted not to include this in the video because everyone’s house and climate is different, so the effect would be too varied.
@@daviniarobbins9298 to put it in context, our 2014 Tesla S uses the non LFP cells (that last for an insane amount of charges LFP is lower power but 5 times longer lasting)...mine are the standard 18650 lower cycle cells.... we have done nearly 170k miles in it and have lost about 7% range after 8 years. Solar is much kinder to a battery than asking 350Kw from a car at times. 100A is 5,000 watts ...nothing to a large solar battery that shouldn't really be discharged to zero too many times if you've got the calculations right. I aim for 20% at least left by morning and charger to around 90%
I have just installed a heat pump via Octopus Energy. I agree this isn't going to save much on running costs but initially I am doing this for carbon reduction . It has cost me £6k and includes replacing 11 of my 14 radiators. My boiler was due to be replaced so I would of spent maybe £2.5k ish anyway and our old radiators were a bit rusty and dilapidated. I have an Electric car and solar panels which is already saving about £900/annum overall so the next step will be a battery which will also help to reduce cost of running the heat pump a bit using cheap night rate electricity and maybe some solar that we currently export in the autumn and spring months.
Put your washing machine on timer mode and timeshift it to the cheap period: that's about 2kw a day you don't want your battery to have to supply. Also get solar if you have a South or east facing: it just takes a sunny morning and that 9kwh battery will charge to full from around 20% by lunchtime if you can fit even a 3kw system (like mine), meaning if you keep an eye on a solar forecast you can get away with only charging to 50% overnight way more often than you'd think. Without solar yeah - just charge to full every night, but consider keeping an eye on your usage patterns and setting it to discharge only at certain times or avoid others: the oven will suck huge chunks out of it, for instance, and you don't want it therefore going flat right before you start cooking, because thats likely 3kw or so which is a significant percentage of your daily usage, like the washing machine, but it's something you simply cannot timeshift to the early hours. Slow cookers and air fryers are also your friend with a battery, especially slow cookers. Laptops + external monitor and keyboard/mouse are better than desktops. And so on: you want low constant draw more than you want big hits. A dehumidifier rather than a tumble dryer (unless you have a suuuuper efficient tumble dryer but then you're an architect you can probably afford one of those and a house big enough to fit one lol! I... Do not). The exception being your kettle, unless you want to get a caravan kettle and wait five minutes for boiling water, that's an inconvenience too far for us :) I've no idea about the heating options I'm still thinking about them, but I figured before I electrify, I should look at generation and storage, so as to be able to have money to save for the heating and water. So far... Yeah it was definitely the right decision. I don't really know why the govt aren't providing grants for my kind of set up, if not just doing it at scale - I did some quick maths last night and assuming there were no savings from economies of scale it would cost 16billion to install 32gw of solar and battery storage - only 1 billion of that is panels - and take up only 1m square metres which is about 8 X 100m X 100m space per county in England, far less if we include all of UK, which of course we should. There must *easily* be that kind of suitable roof space in the UK. Provide the 5k grant for up to ~10kwh battery storage per household, space permitting OR towards a heat pump. Or other generation/insulation/storage systems. Now is not the time to limit options not with our housing stock! Anyway, the money is 5k up to 30k houses per year for 3 years: a mere 90k homes and a mere 450million over 3 years. So spend 1bn more and give over 8 x100m square space per county to solar farms, and pump as much money as possible into whatever grid storage systems are cheapest per watt at scale, and let householders pick up the best energy saving/generation/heating/storage options work best for them. Aaaaaaaaa frustrating! ANYway: Please start designing space and physical support for all this kind of stuff, if not designing it in in the first place. If govt won't legislate it's up to firms to just... Do it. ...er.... Bit of an epic comment. Enjoy the rest of your bank holiday Monday :D
That has to be the most epic comment yet! I am run off my feet with the day job just now but will get back to you in due course with a suitably epic response.
I'd add to that list: electric pressure cooker (eg instant pot). Super efficient because they're insulated, only need to be on for a short time and don't waste energy as steam (which you therefore don't have to dehumidify or vent away). Another benefit is that you don't have to plan anywhere near as much as with slow cookers!
@@RaglansElectricBaboon you are probably right but I have bad memories of being fed tasteless mush from pressure cookers in the 80’s plus, I have two boys of my own who are fussy eaters. I wonder how a pressure cooker compares to a casserole, in energy usage terms.
@@RealLifeArchitecture garbage in , garbage out. If you don't put flavour in you won't get it out :-P Instant pot is rated at 1kW and takes about 15 minutes to steam/boil cook potatoes. It's not on continuously for that time but does need to heat up first. So about 250Wh for a load of spuds. I don't know about casseroles but seeing as the instant pot can do slow cook as well I reckon there's some sciencing to be done. Get your two boys onto it!
Thank you very much for your work. I live in Eastern Canada (Quebec). Hydro Quebec is promoting a package which consits of a heat pump combined with heat storage unit within a forced air furnace. Am I wrong in assuming this is a very appealing combination? The utility 's goal is to eliminate the burning of fossil fuels. Thanks again.
Thanks for getting in touch, I love hearing from people in other parts of the world. Forced air furnaces aren’t something I am familiar with. We are just beginning to look at heat storage units in the UK. Things are starting to change, slowly.
Thanks for sharing, the numbers stack up for your circumstances, have you considered PV and battery at the same time? You would save the VAT doing them both together? I would add that your electricity consumption even without the EV seems rather high - have you looked at reducing this first?!
3.5 gain on your heat pump is very optimistic. When temperatures are below zero expect no better than 2 times. This is why they should only be used in very well insulated houses that already use little energy because direct electrical heating will be used if the heat pump output drops too low.
Really helpful and looks like my decision to install battery and solar was the right one. You might also look at Tepeo an electric system which replaces a gas boiler without having to upgrade radiators etc but works on the same principle. I don't kniow the price. the everything electric show youtube channel had a video.
I am currently planning a new build 4 bedroom bungalow and I am researching both Air and Ground source heat pumps, both have their advantages. I was quoted £13.2k for air source which included a 100L and 250L water tanks. The calculations say a saving of £878 per year. I am also looking at solar, the property will have 3 phase power so the Giv energy is no good, there are some 3 phase systems which will cost about £11k with batteries and PVs.
Interesting Topic and your correct that a battery set up will be more beneficial than Ashp . Your Ashp will almost certainly not provide the cop you quoted. Add solar Pv to your battery set up and your savings will be even more . The government hasn’t thought this push for Ashp through properly and despite what’s being said I believe the gas boiler will remain. Tests are already underway in the Uk where they have added a small percentage of hydrogen into the gas and this has had the effect of bringing down emissions to almost zero which is the main goal. Worcester and Baxi have already began manufacturing hydrogen ready boilers. Instead of rushing in buying electric cars , Ashp etc … I would suggest waiting 2 or 3 years and see what develops plus I wouldn’t base buying batteries on the premise that cheaper nighttime rates will always be available.
This is a well thought out video however there are some further understanding and calculations regarding peak power and use curve you need to consider. I know this as I followed a very similar process before installing a ASHP, solar and batteries. Your battery output is limited to your inverter output and battery discharge rate. If you exceed either of these figures you’ll draw from the grid even if your battery has change. For example. Taking the givenergy system you mentioned, the inverter has a max discharge capacity of 3.6kwh and battery 2.5kwh the most you’ll ever be able to draw is 2.5kWH at any specific time (according to Givenergy). So, you come in after work, you turn on a few of your appliances, kids doing the same and whilst you’ve got the cooker and Kettle on you’re drawing 4kwh. 2.5kwh from your batteries and 1.5kwh from the grid. At the end of the day you’ve used 10kw but only 6kw from the battery. The second issue already alluded to is battery utilisation. Your calculation assume full utilisation of the battery. Whilst you may be using more than 8.2kw a day, if your peak energy exceeds your battery delivery ability you may not exhaust your battery thus making it less efficient. So, you need to understand not just your energy use over time but also your peak energy curve and ensure your system matches it. For example, if you find your do exceed 2.5kwh at any time you could fit 2x 5kw batteries and a 5kwh inverter allowing you a max discharge rate of 5kwh. This however costs more. The only way I could get the numbers to work was to install an ASHP, solar and batteries. The heat pump was a 12kw, 20kw of batteries with 8.6kw of inverters and 6kw of solar. I had to pull in a few favours and accounting for government insensitive my projected energy costs including investment should be between £1500 and £2000 for a large 5 bed house. Investment cost written off over 10 years. HTH
Thought I’d add my situation, I’ve and east west solar setup with a Powerwall a Zappi car charger and an Eddi that diverts solar to heat water. I’m also fortunate that I got in when FIT payments were about to be fazed out so I also get about 8 p per kWh generated with amounts to around £400 a year. The Powerwall holds 13.5 kwh of energy that’s charged up during the winter when there’s little solar, on night rate electricity currently, 7.5p per kWh. That is usually enough to see us through the following day. Before the current crisis our total gas and electric bills, when all was taken into account was near to zero. That’s allowing for the FIT payment and the estimated amount I spent each month on diesel that I no longer have with our Kia Nero EV. During the summer months our car is charge up on excess solar energy.
Hi Neil, I’m coming to the same conclusion myself… the heat pump is more about saving carbon reduction than money. Just wondering why you haven’t bothered with a dual tariff for the EV before?
This is a really good video. It clearly makes the point that ASHP only reduces the heating/hot water costs. So many ASHP evangelists never mention the sky high electric costs. I deal with all forms of boilers/ASHP/Solar etc and the bottom line is there is no silver bullet that solves all problems. Ideally we could have solar feeding battery storage and then the heat pump but you just need several days of poor sunshine and you are in trouble again. In the current economic climate, the main reason I'd have for installing a heat pump is for cooling during the summer months. This is becoming a big concern in the UK, especially for homes that are well insulated for the winter but have poor ventilation during the summer.
What is your method of heating in the battery storage case? I may have missed it. I see that it needs either electric resistive heaters or heat pump or electric boiler of some type (e.g. ZEB). What is the installation implications for this as I understand your house currently uses a wet system. Great video to see your calculations. I find this subject challenging and there must definitely be space for some honest, independent, online comparison tools using input such as current gas/electric usage, number of radiators, square meterage of house, etc. I look forward to your update which will apply some of the missed factors raised in previous comments.
Certainly one of the best videos I have watched on the subject. 🙂There is a lot of greenwash and grossly unscientific discussion on you tube but this is not. (and I am well qualified to know the difference!)
Great vids. I think if you could factor in the cost of adding solar cells to charge the battery during the day and adding a grid tie system to sell on extra generated solar power to your electricity supplier, it would be interesting to see the cost and savings.
If you install solar and a battery, the solar is mostly going to replace the cheap night-time power that charges the battery. i.e. it's only generating 10p/kWh. If you do export any, it will be lucky to earn 5p/kWh. Export rates are very low now the subsidies have finished. If you just look at the hardware costs, you'd get about a 10 year pay-back. Installation cost varies widely depending whether you can do it yourself or need a load of scaffolding, but it might push it up to a 20 year pay back. OTOH, every time electricity goes up, that pay-back period will get shorter.
This is a well thought out video however there are some further understanding and calculations regarding peak power and use curve you need to consider. I know this as I followed a very similar process before installing a ASHP, solar and batteries. Your battery output is limited to your inverter output and battery discharge rate. If you exceed either of these figures you’ll draw from the grid even if your battery has change. For example. Taking the givenergy system you mentioned, the inverter has a max discharge capacity of 3.6kwh and battery 2.5kwh the most you’ll ever be able to draw is 2.5kWH at any specific time (according to Givenergy). So, you come in after work, you turn on a few of your appliances, kids doing the same and whilst you’ve got the cooker and Kettle on you’re drawing 4kwh. 2.5kwh from your batteries and 1.5kwh from the grid. At the end of the day you’ve used 10kw but only 6kw from the battery. The second issue already alluded to is battery utilisation. Your calculation assume full utilisation of the battery. Whilst you may be using more than 8.2kw a day, if your peak energy exceeds your battery delivery ability you may not exhaust your battery thus making it less efficient. So, you need to understand not just your energy use over time but also your peak energy curve and ensure your system matches it. For example, if you find your do exceed 2.5kwh at any time you could fit 2x 5kw batteries and a 5kwh inverter allowing you a max discharge rate of 5kwh. This however costs more. The only way I could get the numbers to work was to install an ASHP, solar and batteries. The heat pump was a 12kw, 20kw of batteries with 8.6kw of inverters and 6kw of solar. I had to pull in a few favours and accounting for government insensitive my projected energy costs including investment should be between £1500 and £2000 for a large 5 bed house. Investment cost written off over 10 years. HTH
If you don't have an EV solar panels and storage are a massive win at the moment. Agile export rates are as high as 18p throughout the entire day so a reasonably sized solar array (6kwp) can easily provide entire house consumption, charge battery storage bank AND also export to grid at around £3 per day. A heat pump wont be doing much during the summer months, whereas the PV and storage can generate money beyond the SEG.
@@RealLifeArchitecture an update on this. Export rates are as high as 80p a unit now and every slot in the entire day export rate is above the import rate.
Air to air heatpumps, AKA Aircon, are much cheaper to buy and fit than air to water HPs. There is minimal disturbance because no new rads have to be fitted and you get cooling on hot days. Air to air is more efficient too, because there is one fewer heat transfer process. No regular maintenance is needed either. Downsides, which no-one talks about, are low level noise, no hot water, and the de-frost cycle which periodically sucks heat from the house to clear ice from the outdoor unit on cold humid days. Aircon works well with solar pv, providing cooling at zero cost during the day. Battery storage can return the free solar electricity at night to give cool bedrooms. Aircon already benefits from the economies of large scale manufacturing. It is only the Brits who seem to be stuck in the past with water based systems.
Probably true but, as you pointed out, it’s almost unknown in the UK. I’ve been in homes from 1970’s with air heating and they have a lot of ducts built into the floors and walls. Retro fitting these won’t be easy in older properties.
Really good vid thanks, clacs were really spot on, if you added solar to charge the battery during the day this would reduce your electric bill a better way although the initial cost is roughly 6k for 4KW decent system with microinverters
You would save a good chunk of money just by switching energy tariffs to day and night rates regardless of having battery storage. Most EV owners are on these tariffs as it in pretty much all situations saves the bill payer money if they’re charging cars at home. As for the ASHP, you didn’t factor in the savings made from removing the gas meter which at your standing charge will be around £100 per year. Or the savings you’ll make in maintenance as ASHP require much less than gas fired boilers. All in all, battery storage is the better option especially if you factory in solar PV panels. You can even sell excess energy back to they grid at higher rates if you get the correct energy tariffs.
Of course the downside of ASHP's is the lifespan won't be as long as a gas boiler and any repair bills will be way way higher. Gas boilers sit inside in a nice warm house. ASHP'S sit outside and work in the worst environment.Cold wet dreary weather. Worse they are expected to work harder the worse the weather gets. This has a serious effect both for efficiency and importantly durability. If you honestly believe this "20 year lifespan" nonsense oft touted I have a bridge to sell you. All the savings will be wiped out very quickly and you will be staring at dark red ink when looking at whole life costs. I've been in the air conditioning industry since 1982 to date and believe me, whilst equipment is more energy efficient most of the progress has been making equipment adapt to enforced refrigerant changes not for another reason. One thing is for certain, those air conditioning units of 20+ years still chugging away are being replaced with units of a 7-10 year lifespan. Things ain't wot they used to be quality wise. On the upside, there are several potential upticks in efficiency on the horizon including vibrating compressor technology and molecular electronic heating which will up the COP but for now I'd be very cautious on splurging vast sums on equipment thinking you'll save in the long run. Chances are that's possibly a very costly mistake. 👍
I'm looking at both of these options, looks like for me battery and solar first. My only comment is that obvs you shouldn't subtract the EV overnight saving as this is possible without the battery. But even saying that, i would say with the current electricity costs you are looking at less than a 10 year payback for a battery.
Maybes if you were building a house from scratch installing a heat pump would be a good idea? Combined with a solar system and battery storage? I would install a better inverter though, say 6kw. An inverter that can handle up to 6kw in and out.
Thank you for a well laid out video... spoken in lay mans terms.. I have Solar panels with FIT...and was concerned which way to go in an older property... (1970's bungalow ).... the thought of going thro new radiators, replacing a gas boiler not even 5 years old etc etc.. and all the upheaval involved....... I spoke to several friends with batteries .and they all said it was batteries all the way...they had turned heating water / rad temp down to 55 degrees ,,, and were not impressed with the heating of the house...........No one I know has ASHP fitted ..These all seem to be fitted in NEW BUILDS with Under floor heating .with modern insulation etc............. . .SO...... I chose Batteries a few months ago and watching this video has made me feel " I've made the correct choice "..
Just went for Solar 4.4Kw of panels with a 17.4Kwh storage battery - will continue to run a gas central heating system until either the price of Heat-Pumps comes right down or gas boilers disappear forever - the saving isn't there yet with Heat-Pumps & I'm also wondering about reliability 👍
I agree. Maybe in 5-10 years, with mass production and the economy of scale, heat pumps will be cheaper. They still won’t get over the problem of needing underfloor heating to work efficiently but if a pump costs £1k as opposed to £10-15k you could put a couple of them on your house and run radiators, backed up with some electric storage heaters / immersion run from off peak tariffs.
@@RealLifeArchitecture It's the additional cost (and hassle) of putting in underfloor plumbing for it to be most effective - most folks have radiators which isn't so good - maybe I'd be better with electric underfloor heating with already getting solar 🤔
Instead of water Heat Pump, I fitted two split Air-Source Air Conditioners and use these as heaters in Spring and Autumn, falling back to gas on very cold days. I heat Hot Water separately and the Air Conditioners work great as heaters and the benefits of cooling in Summer. Instead of £15k plus for Heat Pump, divert Solar to Hot Water and pay for the electricity in winter to heat it (I fall back to gas). £2000 for the Air Conditioners. Solar is free so although it takes longer, an immersion heater is a lot cheaper to buy. Other than that, a small eBay Water Heat Pump for £1500 will efficiently Heat water. Even at this, I can't justify the costs against what I'm already saving with Solar, battery, hot water and car. Separated heating and Hot Water is key.
How things might have changed with electricity price rises. But My experience of using an EV tariff plus a an ASHP is that for 5 months of the year no daytime electricity is used for heating and hot water. And indeed for most of the year the heat pump runs hard overnight, lower COP because it is colder and the savings are much higher than your calculations. Pair a heat pump and a battery and charge your car overnight and it is a win, win, win situation.
What a crisp, to the point, full of facts, video with numbers based on real life products. Thank you Neal, just what I was looking for. I have solar panels but wasn’t sure if to get ASHP or battery back up. I see you have a Tesla, if not already done, I would like to see your review on its + & -. Personally o think Tesla needs a few years to iron out it’s done very basic issues plus I really despise and tablet stuck in the middle of the front dash. Thanks again for a fab video.
Thank you for the kind comment. I’ve had the Tesla over 2 years and love it. There are some things which annoy me but, on balance, it’s great. Check out this video on bidirectional charging ua-cam.com/video/Re3QkHhuG1c/v-deo.html
Good video, promotes thought! A few things missed. Depth of discharge is usually 80%, so really only 80% of the battery available or the batteries will degrade too fast. Losses in converting AC to DC for battery and the back again. Also 15kWh is a lot for two people you should be able reduce that quite easily, requiring a smaller battery. Time shift energy to cheap rate for high demand appliances, washer, dryer, dishwasher ,bread maker etc. Octopus Go are still offering 7.5p kWh cheap rate in Aug 22. That all being said, I have a 20kWh battery array going in next week to move 100% of my electricity to off peak 7.5p kWh. With peak rates moving to 50p kWh this winter that gives me a less than 5 yr ROI on a system that should run for 20 yrs. Using the monthly savings created back into an interest free loan paid for a new system gas boiler and immersion heater and moved them so in 15 years all ready to put in a new heating system. This allows me to move hot water generation to cheap rate high efficiency and off the 58% gas efficiency for hot water supply and using batteries to ‘top up’ hot water during the day. Finally adding 2.8kWh solar array to roof of our shed, cheap to install and reuses battery inverter during the day to top up battery. Allowing me to go longer without gas boiler central heating. At some point in the future when cheap rate is not as cheap will add another 8kWh to the main roofs.
I need to do something like this, I have gas and electric so really need to do something. I have read soon a combination of hydrogen and gas will be used 30% hydrogen which will reduce costs massively but you need a boiler than can support the blend
@@leejohnson197733 the batteries are in and operational, the new boiler/immersion go in tomorrow. The new boiler supports hydrogen mixes, so if they do add hydrogen should be ok. Although, not sure how viable hydrogen is going to be given the massive, to the best of my understanding, amount of electric needed to create it. The rise in price of electricity and looking at 78p per kWh in Jan means the batteries will pay for themselves in less than 3 years so my gamble should payoff.
You should mention that heat pumps act as a grid stabiliser. The more heat pumps there are, grid base load would be relatively higher and peak load lower - this would allow us to have cheaper electricity generation. Alot of people forget that heat pumps are the often most efficient way to use ANY source of energy to heat a building. It makes more sense to burn gas in a power station to make electricity for heat pumps than to pipe it to homes to burn for heat. (A modern power plant is about 40% efficient after transmission losses), 10megawatts of gas procures at the power plant 4 megawatts of electricity Electric resistive heaters would give you about 4 megawatts of heat Burning the gas in the houses would give you about 9 megawatts of heat (we are very good at getting energy out of fuel on site) - so seems rational to do this... BUT. If you use that 4 megawatts of electricity in heat pumps COP 5 you end up operation at 200% efficiency of the gas, a 100% bonus. Literally more energy than the gas itself contains ends up being put into buildings. You only need COP 2.5 to break even with on-site fuel burning, and COP 6 units work in most environments.
That was very interesting and potentially useful. As you mentioned in your pinned comment #4, the off-peak tariff is no longer offered by my supplier, which might have helped us as our son has an EV and we also have a garden spa (sounds posher than hot tub!) which could use night time electricity for heating. We are having a stand alone wall mounted air conditioner/heat pump fitted for summer comfort and winter heating supplement- our normal heating is by gas boiler & radiators with a gas fire that can also be used in the event of power cuts. Have you had any advice on the maintenance costs and battery life? I also have great concerns about the robustness and spare part availability of control systems- I have noticed a worrying trend of recent electronic failures. In the last few years since we had smart meters installed, 3 have failed with another that failed during its installation. We also had to replace an oven due to a burned PC board- never had these problems with British made ovens-our Creda with eye level grill lasted fault free for 27 years.
Ive been told that batteries like the one in the video will degreade to 80% capacity after 3000 cycles. So over 8 years of being used every day, the battery will loose 20% of its original capacity. Compared to the battery in my model 3, this one has an easy life.
Great video. My real world consists of solar panels and a Give Energy battery. At the end of the day this gives me free electricity, which runs my house and my car too. Combined with FIT (Feed in Tariff) I also receive payments, which I use to reduce my gas bill resulting in great savings. An air source heat pump would mean purchase cost of far more than I paid for a battery, replacing my rads, my combi boiler, my micro bore pipes, installing a water tank, plus cost electricity. This would mean an ROI for me which I would never see.
You also have to factor in the costs of insulation and improvements to existing pipework to make an Air Source Heat Pump a viable alternative source to a Gas Boiler - in many older properties you'd have to rip out all of the existing pipework because it's bore is too narrow - I am on a journey (it will take us about five years I reckon) to wean ourselves off Gas and move to an ALL electric based energy source, which will involve - at various stages of the process: Ripping out many of the existing radiators - particularly those on the upper floor Installing Battery Storage Moving to the dual period electricity tariff referenced in this UA-cam video Changing our ICE vehicle to an EV Installing electric underfloor heating - particularly in rooms on the upper floor Installing Solar Panels and linking them into the battery storage Significantly improving the level of insulation in the house generally - cavity wall and loft insulation? Replacing the smaller number of radiators we retain with more efficient modern alternatives Replacing our gas boiler with an electric alternative Our house was built in 1952 - I've looked at an Air Source Heat Pump and ruled it out as NOT feasible, due to the huge cost and disruption involved in making it work as a potential alternative to a Gas Boiler
We have a 2014 Nissan Leaf with a 24 kWh battery. It's done 75k miles and the usable capacity is now in the region of 75-80% or 18-19 kWh which gives us a maximum range of somewhere in the region of 75 miles on a charge. With the recent crash in second hand electric car prices and the likely number of these older, lower capacity EVs which are on the road, I'd really like to see some sensibly priced tech developed where the battery can be removed from the car and utilised as storage for the home. A quick look at autotrader shows that a car like ours can be picked up for £3-4k. A home storage system with >10 kWh is likely over £10k at this point, and the market for an EV with such low range is going to disappear quickly. I have seen some DIY type systems cropping up on UA-cam but there's no way I'd be putting my house and family at risk by installing something like that. If we can find ways to repurpose batteries from older EVs for energy storage for other purposes, then this will provide benefits for all parties concerned.
Good, interesting video. I assume it's been mentioned elsewhere, but it's not exactly an apples to apples comparison. You already have a working boiler, but you don't have any energy storage. So you've already paid a fairly hefty sunk cost when you had the gas boiler installed or when you bought the house. You might not think about it in those terms, but you of course factor the fact that a house has a functioning boiler when you buy it and would lower the price you are willing to pay if it didn't. In the end I opted to install solar rather than get a battery, as I get paid to export and save money whatever happens to the price of energy. Octopus is making a loss right now on their EV night rate and that's not sustainable forever. The day/night differential is not something you bank on being available for the whole life of the battery, which is why I think you should install solar first and a battery second, if you have the means to do so. Also, if you have a hot water cylinder, you can divert excess solar PV energy into your tank using the immersion coil, reducing your gas demand. I plan to go gas free for my hot water demand, using the night rate to heat the water in winter and on cloudy days. And in summer mostly (hopefully) running the hot water off the excess solar.
Absolutely: sunk cost of existing gas installation; HP installation decorating cost if new rads/pipes; likely higher cost of annual HP servicing than gas boiler (not safety-crucial but said to be necessary for max efficiency); these are all factors overlooked by HP advocates.
We have a converted/extended 1950's bungalow of about 200sqm that currently is heated by an all (solid) fuel central heating cooker. Our annual solid fuel cost is around £750.00. Our electricity consumption is via E7 dual rate with about 43% consumed at night on the low tariff. Our electricity costs from Oct 2020 to July 2022 was ~£950, the annual rate is not consistent for this overall period. I can reasonably convert to heat pump but I will require a 21kW unit that is probably best on 3 phase, which fortunately is immediately available. The house plumbing and rads is already sized for lower flow temperatures as required with the CH cooker although I might simply fit split units off individual units around the house. I will keep and maybe upgrade the CH cooker as it has valuable advantages over simple heating/HW
Things become much more interesting to me when EVs and home chargers support vehicle to home. For our circumstances (vehicle only used on longer journeys on weekends so mostly idle during the week), that would help justify the cost of the car.
V2G would be a killer for me - having a xxkWh battery just sat there for when it's needed would save £££ on a larger fixed larger battery purely for the house...if you have PV then it's a no-brainer
A 2nd (used?) EV with V2L (vehicle-to-load) makes a lot of sense, would have more available KW/hrs than a home battery and it likely would be cheaper. Another big advantage is that it is portable--if you had a local & sustained power outage, you could simply move your EV (storage battery) to a 2nd location (temporarily) for charging.
@@michelem.6104 exactly that - a used 24kWh Leaf used to be around £5k in the UK (more around 6-7 now) but compare that with a home battery, you're looking at that figure for around 10kWh - it will get there but the notion of energy with a vessel to store it in needs to be separated from the 'thing' that is using it - much like the 'multi-tool' batteries for gardening/DIY etc - admittedly the EV needs to have a fixed battery but OEMs need to make that energy available for V2H or V2G and charger/inverters need to catch up to make it happen at a decent price point - it seems ridiculous to me that there is duplication of hardware all around!
Air source and ground source are only viable in new builds with room for the storage tank etc, end of. With regards to battery storage, make sure you note maximum loads as the givenergy can only discharge 3.6kw meaning you will kick in mains for a top up if you put the kettle on and have a standing 400w running house (tv, wifi, fridge freezer etc). Powerwall and some others discharge at 5kw continuous and if used with solar are ac coupled meaning the solar can add to this (we personally can sometimes be feeding 9kw from our battery and solar continuously).
Can’t you use nighttime tariffs for the heat pump too? In the summer you can crank up the heat pump to get the house very cool at night, and turn it down (or even off) during the day? Similarly, in the winter can’t you crank up the heat at night, and turn down the heat during the day? If your house is well insulated, and you keep the windows closed during the day, and keep the blinds closed too, I suspect for many homes this would work just fine. I know people who use this technique who don’t even have time of use pricing, they do it in the summer because the heat pump is cheaper to operate when the temperature differential between outside and inside is smaller.
m.ua-cam.com/video/0f9GpMWdvWI/v-deo.html (by Technology Connections) discusses exactly this at some length, focusing on the aircon in summer because he's based where that matters more. There's a long intro about various forms of energy storage, so if you are mainly interested in his use of his house as a thermal store fast forward to 6:47. He gives figures of what he was saving in summer 2021 when he made the video
@@RealLifeArchitecture Off peak tariffs will be phased out? Interesting, I thought that was the direction things were going around the world. I look forward to the video to learn what jurisdictions, and why, are going a different direction.
Given your very high consumption of electricity (car) you really need to install PV asap to reduce this. Most people who install PV on their roof produce power when the sun shines and not necessarily when they need it but if you have a car to charge that becomes a lot easier to manage. Furthermore, if you had chosen a recent Hyundai or Kia you would be able to use the ~70kwh battery to perform the function of the Giv-Bat without breaking a sweat up to an instantaneous draw of 3.6kw.
Really interested in using vehicle to home charging but is it possible to set it up so it isn't tied to the grid? Otherwise the only times I see it being used in the UK is via the small scale vehicle to grid trials.
Battery storage makes sense when combined with solar. You forgot to calculate that you lose about 5% efficiency when you charge and discharge your battery (at minimum).
The heat pump if installation is done by a good experienced company you should get 4.5 kw per 1kw of electrical power in . Also with the current gas situation and the fact it's carbon free and gas is only going to go up and installation costs will it's best to get one sooner than later 👍
Off-peak electricity will become more popular with more battery installations, so given the law of supply and demand, there will be no savings (soon) by using a battery to cleverly "buy low and sell high". As you mention, the availability of the night rate (off-peak) has already been discontinued in some places.
Great video, thanks. I'm in a situation where I'm trying to move away from oil heating and stinky oil tank that comes with it (no gas where I live), so the main purpose would be for heating water and the house. I think this means air source would be the better option for me, as much as I would prefer solar + battery combo. I see you're a Bulb customer too - do you know if they will honour the reduced night tariff once we're moved to Octopus?
Hi what size battery storage would you need, to have enough stored cheap night time energy to also power a heat pump during the day? maybe the trick is to have a good balance between both systems, in other words does battery storage make a heat pump more viable financially?
Based on over 20 years as a Gas installer, over 70 heatpump installations (new build and retro) and living off grid for electricity for the past 3 years. There's not a cat in hells chance my Newbuild house will have a heatpump, if I'm "forced" to have one to tick a box, it will be "borrowed" box ticked and returned. Solar & batteries can realistically give you 100% of your domestic power for 8 or 9 months of the year, the rest you cover with mains or genny, my annual red diesel bill ( for 9kva genny) is way less than the standing charge for mains power.
You are probably correct regarding new build homes but the vast majority of homes in the UK are old and will be difficult / impossible to upgrade. The gas system will remain for the foreseeable future
Hi Neil, I came to the same conclusions as you and have installed solar with 17.4kw battery storage. I have two electric cars and will also now switch to the “go green” electric rates as we now have a smart meter installed. I am also looking at a heat battery for hot water generation as this can also be charged overnight on cheap energy or from the solar panels during the day.
One other major technology left off here, is one that the public isn't aware of too much, which is of course an MVHR My plan of action is as follows : Get solar panels + batteries first Then an MVHR Then oversize radiators Then a heat pump
That’s a good plan but heat recovery only works in buildings with good air tightness. That usually means a new build. This technology isn’t suitable for the majority of older properties in the UK. They are draughty and the may not be space for the kit. Solar plus batteries is a more usable tech, however.
@@RealLifeArchitecture I saw online that it's still good even at low levels of air tightness Also fwiw, I got a low energy architect, and they advised pretty much the same. I'll be making my house more air tight, regardless . They did however advise against external wall insulation I am also now looking potentially into "air to air" heat pumps ie: aircon but in reverse and just rip out the radiators
That battery sounds small. We started w 5kWh of battery, but it would not sustain the microwave and Induction hob simultaneously. We're now up to 20kWh of battery on a 5kW inverter (Growatt), which seems to be doing the trick.
Problem I have here in the Netherlands is that the ‘night time’ tariff = 0.32 euro while the normal tariff = 0.38 euro. So the gap isn’t large enough for this type of installation.
Very informative, the ASHP will have a 10yr lifespan and is not maintenance free, the batteries subject to chemistry should last longer and far less maintenance. Embodied carbon is a topic if being completely green is you goal and finally, continuity of supply, with battery storage you can technically with a bit more investment operate with the utility being off.
Thanks, I have an old house, very old (1686), so ASHP would be almost impossible, 24 inch walls etc. So I have gone for the usual insulation and now have Solar, home battery, and EV with V2L. I am reluctant to go above my 7.5KWh home battery as the pay back is long, and totally reliant on cheap night rate, if we all get a home battery then the suppliers may no longer offer cheap night rates. Even so I am now updating white goods to high efficiency and load shifting.
Wow those bills are quite big ! One word of caution ... How long is cheap night time electricity going to last ? With people charging EV off peak , the demand for off peak electricity will rise & the discount go down.
Really interesting video - thanks for sharing your thoughts on this. I'm an EV owner too (BMW i3 33kWh) and consume around 2800 kWh of electricity per year to drive 12k miles. In addition we consume another 6800 kWh for other household loads. Our heating is an externally mounted oil fired boiler which is around 14 years old now and is starting to need regular repairs so we were considering a heat pump, potentially ground sourced since we have a 3 acre paddock next to our house. The house is partly a 150+ year old cottage with solid stone walls, and partly an 2 story extension which was added in 2008 so we have a mixture of insulation standards which was a big concern for me if we were to install an ASHP or GSHP. I'm currently refurbishing a 10m x 10m outbuilding next to the house and intend to fit solar panels on the roof but the lead times on installations are pretty long just now for obvious reasons. I did wonder if I should try to get a battery installation in the shorter term to allow me to switch to a tariff such as Octopus Go. We were with Octopus Go at 14.5p and 5p (00:30-04:30) per unit before the energy crisis but the rates are now 35p and 7.5p so the penalty for using power outside the "Go" window is much more severe. The result is that we are better off staying on the standard variable tariff which is 29.84p peak and 21.34p from 01:30 to 08:30hrs. If we did employ battery storage then we'd probably need 2 of the GivEnergy 9.5kWh batteries to deliver the 18kWh or so that we consume daily excluding the EV. So I guess I need to do a few calculations to work out the return on investment of a battery system for my situation but it sounds like it might be feasible. Advice welcome. :)
Your situation isn’t unique, most people in the UK live in older properties, which have been altered over the years. I’ve also had several sources tell me cheaper off peak tariffs are on the way out. I am now thinking solar PV with some battery is the way to go.
@@RealLifeArchitecture yeah it's a good point - we shouldn't rely solely on a cheap tariff like Octopus Go because right now there is no way they are making a profit from 7.5p/kWh at any time of day! Even the Agile Octopus tariff is currently maxed out at 35p/kWh for the entire day whereas it used to go negative on occasion. I dread to think what the unit prices are going to be come the winter because even 29p/21p (peak/off-peak) is artificially low due to the current price cap. I can only assume we're headed into 40p+/kWh territory when the new price cap is decided... I recently took part in an initiative with Octopus in conjunction with the government where they would tell you 24 hours in advance of a 2 hour window where they would actually PAY YOU to use energy. As an EV owner it was very easy for me to reschedule my charging to coincide with that window as well as running washing machine, dishwasher etc. So I ended up making £32 in total from I think five or six such 2 hour windows. I suspect that this might be more the sort of model we see in future where those who are flexible about time of use can benefit significantly by pulling power when supply is plentiful and vice versa. In terms of energy saving, the biggest difference I have made in our home recently was by installing a full set of smart thermostatic valves throughout our house. We are using the Tado system and I'd say it has reduced our heating oil consumption by 40% by allowing us to heat different parts of the house to suit our actual usage. Yes you can do that with manual TRVs as well but nobody is going to go around the house several times a day adjusting them. Our biggest saving by far was avoiding heating our lounge, which is fully inside the oldest part of our house, during the day. But also we save money by reducing heating in various other rooms such as guest bedrooms. We can also boost heating to places like the en suite after we have had our morning showers to help clear the damp air away and dry towels on the radiators. It really has made a huge difference and my wife is happy to use the app too so it's not just for tech geeks like me! :) Lastly, I recently installed an Emporia Smart Home Energy Monitor which uses up to 16 current clamp sensors to monitor individual circuits coming out from your consumer unit. This has been quite eye opening in finding where my electricity is going each day and has already led to changes such as switching off our dehumidifier except when drying clothes indoors as it was costing us over £150/year in electricity to run. Well worth a look.
Very similar setup to mine albeit we have a late 80's large bungalow. Currently running 8kw of solar for house, and 4kw solar for Tesla. Built a 9Kwh battery for car charger which gives about 70 miles a day roughly. The house has 17Kwh battery with another one on the way. Swapped out the Tuble Dryer for a heat pump one that just sips electricity. I was going to go on the cheap rate Octopus Go tariff but think I'll stay on the 30p/20p standard tariff as I really don't want a smart meter installed. Heating I am ripping out the oil burner and all the radiators...emersion heater etc... Putting in Heat Pump to Air Conditioning for heating and cooling. Will be nice to have a radiator free house, positive airflow pressure from attic into house to stop damp. And a Sunamp phase change for water heating I think the dial home newer ev chargers will be the way the government tax electric car use in future, pretty sure they passed a sneaky law during 'c o v i d' that allows entry to your property to take electric car meter readings without a warrant and without your permission. I did wonder how they were going to tax the EV's.
Hi what you are saying doesn't sound correct to me. You haven't included the cost of charging the storage battery. You have assumed its fully charged each day. Surely its not without cost to charge the battery? Also can it be charged within the 4hour cheaper electricity period?
In the ideal world, yes but it’s not always affordable. I made the video from the viewpoint of having to choose between them in the basis of return on investment
Very good Video, Some points. Heat pumps are sold on a 3 to 4 times heat output per KWH, and under perfect conditions this could be the case, A test (under controlled conditions) was done and this turned out to be 1.75, i can't find this info at the moment, i believe it was done by octopus. The next problem, they need to run 24/7 due to the lower heat output, so if you haven't got excellent insulation it's going to be very expensive, and I like to sleep in a cool bedroom, and wake up in a warm one. And the maintenance costs and servicing need to be considered. Now the battery idea is excellent, as you have pointed out. The 6k you mentioned is about right, but i expect 2k of that would be the inverter and fitting. So i would strongly suggest spending 10k and doubling up on the battery, and if you haven't already thought of it fit a hybrid inverter so you can fit solar at a later date if you get the urge. I have been running 10kwh of batteries now for about 6 months and my only problem is, I wish I had 20kwh. The problem with all of this is predicting future energy costs, I see heat pumps in any environment as a big gamble, and can see electric at the very least 50ppkwh or more for the next 2 to 3 years, and gas at 15-20ppkwh, the wholesale price of gas at the moment is over 12ppkwh. Anyway best of luck.
@@RealLifeArchitecture Looking at the wholesale prices, it's been a thing of the past for the last 12 months. Just look at the logic, everyone will be charging their cars at night cheap rate or not, as will be using them in the day, so other than the 4 to 7pm peak the grid will just about be utilised 24/7. The only way round it is solar, assuming you can get enough panels on your roof and some batteries to store it.
There is no room outside my flat to install a heat pump. You should re do this video with October's price cap prices. Electric is now going to be 49p something per kwh and gas nearly 15p kwh with standing charges of 55p E and 37p G. These are rounded up or rounded down figures. I hope you all fixed your energy.
In NZ with ASHPump air to water doing hydronic underfloor heating in a well insulated but cold climate .Night 10hr/day14hr tariff of 6p/20p daily charge 17p .It costs 11 times 6 = 66p/night to heat house .Wood burner needs to supplement space heating for about 4 hrs once a week over coldest 3 months. Well designed house (thermal mass and eaves) mean no summer cooling needed. I have EV also so 6p/kwh drives 3miles ie 2p/mile. Soon we will be able to use the EV car battery as a storage for house use saving the wall battery cost. Yearly usage is 8500kwh at 2.6 pounds a day.
If your car supported V2G or V2H you could use your car as an alternative to your battery or have a smaller lower cost fixed battery (assumes you WFH for the majority of your time).
Yes: in fact he says in another reply that both he and his wife WFH so using the car as a battery makes sense, so long as he factors in the times he needs to keep it fully charged for a planned trip; or if his business requires him to make long trips with zero notice
Good analysis. But there is one area that you missed. The battery system is electronic/electrical. Yes, batteries aren't perfect, but they are good and rapidly improving. The heat pump is largely mechanical for the guts of it. My experience is that mechanical systems don't have the same reliability. Looking at my own home, it is the "good ideas" with mechanical systems that are the ones that fail. Would a heat pump get anywhere near 44 years of life? I think not. My view is to stick to "non - mechanical" systems where possible.
Thing to consider is the lifetime of a heatpump is 20 years while gas boiler is 15+ years, also proves heatpumps are still worth it if swapping out a gas boiler anyway
That's a matter of opinion, because we don't really know the reliability of the heat pumps that are coming into today's markets. There have been big improvements in efficiencies, but only time can tell us those come with hidden obsolescence, not necessarily deliberate. Yeah you can find heatpumps from 20 years ago that are still running. Their SCOP might be around 2 or maybe 3 at best. Today manufacturers are claiming 4. The tech has changed over the lifetime of that unit built at the turn of the century and we cannot assume all the changes will turn out to be for the better I'm not saying that you are wrong. What I'm saying is don't be too sure about any opinion (including mine) of a tech that has doubled its efficiency over the lifetime of an appliance.
Thank you I was going to get a heat pump as I have a gas combi system and my house is of similar size to yours and I have an eclectic car which I do charge only on off-peak electricity a power wall is definitely the way to go plus I am thinking of installing solar panels on my garage roof to charge the car as well and whatever leftover charge can go to the battery now solar cells have come down in price dramatically so I am going to fit 5 full panels to my garage get a controller fit it but not connect it I will get a specialist to do that and check over the system as I am competent in wiring 240 and 12volt I used to rewire houses with my dad who was a certified electrician I used to help him out on big jobs I always go above code as you can never be too careful with current so he will connect to the easee robot car charger as it's over a 1000 pounds for that unit and I don't want to blow it or void its warranty. same with the battery when I can afford to get it installed in my garage which will feed the house during the day I am at home all day as I am disabled now but can still do some jobs it just takes me a lot longer than before between rests. lol but I do believe it will save me a lot of money and when I can afford it get a small wind generator on the house roof to power at night and during the day as well helping me to get off the grid and finally get a company in to install solar panels to the house roof with another power wall so two power walls and then I should be able to stick the fingers up to the power companies and tell them to shove it the robbing you know whats, LOL. no not really I am too kind but I will think it as they are robbing us blind to keep their shareholders sweet it was the worst thing the conservatives ever did was to privatize the utilities of our houses power and gas and water biggest mistake ever this was predicted by Enoch Powell and everybody laughed at him now whos laughing they all said he was scaremongering well here we are now I never liked the man but I respected his views and I could see what he was saying way back then and all that he said has come to past I really wished he had got it wrong boohoo.lol bye
If anyone wishes to save money you have to go off grid and produce your own power, yes there will be a cost to purchase the equipment to do this but if it doesn't rely on an energy company to run you will genuinely save money. Example Solar Evacuated tubes to create hot water, with the circulation pump run by solar .Even this method you still rely on the the water company.
I think that the impressive thing is that electrical heating has now hit price parity with gas heating in day to day running costs. It's less about payback time and more about being a viable replacement for gas. I wouldn't rip out a serviceable gas boiler right now but I would probably replace a boiler at the end of it's lifespan - especially as the future of gas looks unstable but electricity will likely become cheaper as more renewables come online in the long term, it just seems like the safer bet if you have to pick between the two sources of energy for a new system. I'm in the process of buying a house with my partner. it has no central heating atm, we assume it had storage heaters at some point however none are in the property now. We plan to install an air-to-air heat pump system before we move in. Heat pumps make sense for us as it'll effectively cost 1/3 less to heat our home vs resistive electric heating. Another benefit of having our heating supplied via electricity is that it will improve the payback time of a solar+battery system for us when we look to get one in the future.
@@RealLifeArchitecture the OP is talking about using a heat pump, not resistive. Your own calculations in this video show the heat pump to be cheaper than gas. Why would you link to your old video saying resistive heat is more expensive than gas?
@@iareid8255 That's likely a short term thing and as renewable is getting better and cheaper all the time, it's likely going to work out cheaper than all the other alternatives. There is also the option with renewables that you can install them on your own house and with that, I think longer term, going the electric route with heating is likely going to be the better option if you can generate enough energy at home. Still, I tend to find the best solution is to reduce heat loss in the home whiles reducing heat getting into the home and overtime, replacing items around the house with more efficient ones, something we've been doing at my house for about 15-20 years and reduced our energy consumption from around 30 kilowatts per day to around 16, this is whiles having more computers and other tech gadgets around the house and I think it's likely less than 16 now because I last checked about 4 years ago and since then, I replaced my induction hob and dryer, both of which are a lot more efficient, especially the induction hob which the older one was something like 7 kilowatts whereas the new one is 3.6, so at a guess, I suspect I'm probably using around 14 kilowatts per day. Without other advancements in tech, there isn't really much more I can do apart from heat pumps, solar, wind generating and battery storage tech, all of which are quite expensive. In any case, what I found remarkable over the last 2 decades is how you can reduce your energy a lot without changing your quality of life, in fact I would say the quality of life is better because I'm using more goods even thought I'm using a lot less energy.
@@RealLifeArchitecture Many people ask me whether or not it's best to leave the immersion heater in the cylinder on all the time or turn on only as needed and I've never had an answer for them, only for them to experiment themselves. Would this be something you would cover?
You are using the most optimistic figure for airsource heatpump efficiency, you will only get 3.5Kw for every 1 Kw used by heatpump in the summer at 25deg C ambient or higher ( when you need the heating least ) - but in winter at >10 deg C you will get nearer 1.5Kw of heat for every 1Kw of power into the heatpump - this makes the battery even more attractive, and much less disruption to your house.
Would you consider the savings made by swopping the gas with heat pump and supply with battery it seems a viable option. Storage tank as buffer which heat up with night tariff with heat pump also would work.
Not a huge dent but if you also removed your gas supply, you'd be saving another 100/annually due to the standing charge removed. So rough saving of 235 annually, still 25.5 years to get ROI
A really useful video. One important thing to consider is the range of available heating options. I completed a self build in Cornwall 15 years ago and installed an air-water heat pump with underfloor heating in a concrete slab downstairs. Because of the level of insulation we only installed towel rails in the 2 upstairs bathrooms and the house was never cold, although we did run a woodturner on colder evenings, leaving the lounge door open so heat would naturally convect upstairs. We ran the whole house on economy 10 which gives 10 hours of off peak, including off-peak times in the afternoon and evening. It probably worked out slightly more expensive to run than gas, but that wasn't an option in our village so we were comparing against solid fuel, oil or propane making it a simple decision. 15 years on and the ASHP unit expired, just as we were agreeing a sale on the house, and had to be replaced - bad timing. Now I am looking at the whole thing again. We have bought a 1970's 2 bed semi in another part of the country - our son will be living there as we are working abroad for a while. I don't have any figures for current energy usage but, for me, doing nothing is not an option as the house currently has manually controlled storage heaters and an an old copper immersion tank with only an insulation jacket. The roof faces almost east-west so not ideal for solar and on a 2 bed house isn't huge anyway. Considering I have no wet heating system in the house at all, some form of solar system and/or air-air HP is looking like a promising option. Battery systems are fairly new to me but the figures seem to add up, particularly when combined with PV. Another option I have come across which may work for the house are smart a controlled water tank and storage heaters that automatically heat using PV output and cut down on electric usage over night. There is however the issue that most heating is required in the winter when PV output is generally lower. I'd be interested to learn more about the output that could be expected when installing PV on a less than optimal roof, and would welcome any recommendations for this particular set of circumstances.
Wow! That's a similar situation I'm contemplating with a prospective self build (east-west narrow strip of land); so glad the YT algorithms lead me here 👍🏿
@@RealLifeArchitecture If my 'land disposals' enquires prove fruitful and I get the nod for my self design and build (usual planning/local design guide constraints), I'd love to keep you in the progress loop 👍🏿 ps, thx for a brilliant, logical presentation - subscribed!
The quote you received for the air source heat pump seems very low to be honest. Did that also include the installation of the hot water tank and all the plumbing/electric for that? Thinking about the battery idea, it might be a good idea to charge the battery at night and use it to power stuff during the day, that alone would save you/people a fair amount of money, as you'd be paying 1/3rd the price. I have the economy 7 meter/rate in my home and it never dawned on me to run things at night, primarily because I keep forgetting modern day dryers and other appliances come with a delay timer. I often wonder how much I could've been saving if I had done that with my dryer in the garage for all these years!
We have an ASHP and home battery installed. I agree with your maths - but the ASHP gets much more attractive when a home battery is also installed. My FoxEss 18.2kWh battery cost £7,500 (with a usable 16.4kWh) which covers 100% of my home demand in the summer - we'll see about the winter. I do think ASHP economics are muddled by the current (relatively cheap) price of gas. Even at a 4:1 COP, and ASHP is effectively delivering the same heat output as gas for a similar cost (because 1kW of electricity is 4X the cost of 1kW of gas) - so no opportunity to offset the high initial cost - but that changes with a big battery + ASHP.
Looking into battery storage myself. I would need 14kw average. I've been quoted 10k for install. As an electrician I have friends who install so will see if I can get better price. Some problems are battery invert or can not power high demand items, plus ev demand could soon use up night time economy tariff. So apart from my solar putting some surplus into battery it's a big gamble.
If the night time tariff changes, it will likely be to an agile tariff with an even larger differential. Electricity companies really, really don't want EV owners charging at peak times!
If you would like to book a consultation with me you can do so here - www.reallifearchitecture.co.uk/online-services
Please read the terms and conditions before you book.
PLEASE READ BEFORE POSTING!
There are a lot of points being repeated in the comments, so for clarity;
1. I didn't use solar in this video because everyone's roof geometry and location are different. I will be investigating solar in the future as battery + solar PV is probably the most effective system.
2. An off-peak tariff would charge my EV for less without needing to install a battery but since my wife and I both work from home, the more expensive daytime tariff reduces the overall savings.
3. I checked the price of supply and installation with several vendors, some may disagree with the figures in the video but they were as accurate as I could get at the time.
4. Since making the video it seems off-peak tariffs are being phased out or the savings massively reduced.
5. I did not account for the daily standing charge in my calculations, my apologies.
6. Air-to-air heating is probably more efficent than air-to-water but is not widely used in the UK.
7. bidirectional charging, also known as vehicle-to-grid, is on its way and may make stand-alone batteries less relevant- see this video ua-cam.com/video/Re3QkHhuG1c/v-deo.html
8. A storage battery should only discharge about 80% of its capacity in normal operating conditions. This will preserve the life of the battery and most will last 10+ years.
9. The efficiency of the ASHP noted in the video is optimistic and probably only achievable during mild weather.
A well insulated & ventilated building will reduce the energy required to heat or cool a building to the extent that the method of heating is irrelevant
Thank you for clarifying the solar question - as I was sitting here thinking - if only he had solar to top up the batteries during the day, and thus offset how much draw down he has from the batteries in daylight hours - or you can extend how long the batteries hold up.
A friend of mine uses combinations of batteries and solar - in the summer months he is completely off grid, and in the winter he has to use the grid either during the night, or to top up on the really dull days - his bills are incredibly low. And he runs his electric car via this set up more or less at nil cost to fill it up.
You should also check out a solar boiler, the hot tank goes before my HR boiler, for at least half the year I'm not using any gas for heating shower/tap water. I got it at the same time as an air heat pump which supports the gas hr boiler home heating.
Previously I'd already got loft/floor/cavity insulation and solar panels.
The Solar boiler/heatpump/HR boiler combi reduced my total electricity/gas bill from €2000 to €1000
The cost was €12.000 minus €4.000 subsidie.
That was an 8 year pay back before the prices went sky high.
@real life architecht do the givenergy systems also have backup function in case of power outage?
I see also in the sales blurb it says it sits alongside an inverter, so this is not the full package??
so far from what I have seen only tesla and sonnen are offering the package that does the lot.
For what it's worth I think all of them are also being too clever for their own good by having their systems governed by monitoring from a cloud/database that can be "outaged" or hacked from a security perspective.I would be happier with a mechanical relay to govern mains/backup supply and a local timer of some sort to govern top-up from the grid if the battery needs it.
It's already known that some folks hostile to us have been targetting core infrastructure via cyber,so the less connections the better.
@@bigmacntings7451 Fairpoint - my solar system in my campervan uses an inverter with three types on input - solar, mains and the vehicle alternator - with a leisure battery back up - all together they successfully manage a 12v fridge, lighting and charge my devices, even on the darkest days of the UK year.
I now offer online consultations if your property is in the UK, check out my website for more details www.reallifearchitect.co.uk/online-consultation
Nice and succinct video. I have very similar scenario. One other consideration: If you expand storage, then you can power the Air/Ground Source Heat Pump at the much cheaper Tarrif also. However, one omission: you need to 'set aside' a proportion of the savings, as storage solution(s) won't last for ever. Totally agree the storage is the logical step, especially after going E.V.
Hopefully the 'Heat pumps' will get better efficiency with new Motor tech etc. and Storage will get more economic too.
Thanks for your comment, it’s a topic I will revisit in future videos
As someone that fits both various types of heating systems and battery storage, Battery Storage before Heat Pumps every time. There are the factors you've stated but beyond that which people often aren't informed of or don't think about is decorating after an ASHP installation, the hidden costs so to speak. With Battery Storage and solar it's generally minimal distruption and doesn't effect decor to the same degree as fitting larger radiators (if possible), having the floors up to run correctly sized pipes (if within budget) and although we will make good on our company we can't match in the decor or guarantee the floors especially if they're laminate coverings etc will come up without damage.
Also Air-to-Air heat pump systems are far more efficient than the water based ones due to the temperature delta being 15 instead of 45. Generally though if a Gas appliance is pre 2001 (non-condensing) Solar + Battery or even just battery on its own and swapping tariff will often save more money than a heat pump. The easiest thing you can try is running the current system flow temp at 55c or below to see if the property maintains temperature. If it doesn't don't swap, get more insulation and consider the battery storage, they'll make a bigger impact in the majority of cases.
That is fantastic to hear, thank you for taking the time to comment. Good to know I got the overall comparison correct.
Interesting comment regarding air to air heat pumps being more efficient than air to water. I wonder why they aren't more popular in the uk? Compared to the US!
@@TC-V8 A multitude of reasons, floor void size being a major one. The expense of changing systems entirely being the second for existing properties. Most existing properties would need smaller diameter tubing back to a central location basically a Zender setup (seems to be the most well known in the states currently).
For new builds it's a no brainer but the government doesn't want an increased summer load on the grid so there's no VAT exemptions or insentives, the mere fact if homes were built to Enerfit or Passive standards that the loading during the year would be minimal regardless doesn't come into it. As such our building practices haven't really changed since the 1930s with only slightly thicker cavity walls for slightly thicker insulation, even that hasn't increased substantially since the 1990s though.
@@TC-V8 psychological reason is that people are used to having water circulating around radiators. If I understand correctly (and please tell me if I have got this wrong) an air to air heat pump has pipework containing some fluid that's essentially a refrigerant running to every room and a condenser unit everywhere you want heat. That may be cost effective but it's not what people are used to.
@@effervescence5664 Also consider that even with an average COP of 3.5 over the year, gas is 3.5 times cheaper than electricity, currently
People typically aren't going to shell out for an ASHP if there's no real payback period. That, and in older homes, the COP might be just 2.5 which means that it would cost even more to run
Suddenly, ASHP doesn't seem like a decent idea. I'm allowed to get a maximum of 16 panels on my house, which should mean that I can run self sufficiently through electricity at least, and the remainder is energy that I could store in batteries for an ASHP
The government is pushing ASHPs before they've pushed solar panels + batteries
Nice straightforward presentation of the facts. There is one limitation I have recently become aware of the maximum supply rate to a house has a limit unless you have the main supply upgraded. This places a limit on how much most people can download during the off peak rate period. Worth including in your calculations. 👌👍
True, I have heard similar from others in the comments
Pretty bang-on with the calculations. I'll add a few points I think might be useful to know for people (I'm ASHP+Solar+battery owner):
- When replacing an older boiler like oil-fired, biomass or gas backboiler, your ROI might be sooner. We replaced a backboiler which was on it's last legs anyway & 20% less efficient than todays condensers, so overall our running cost is about the same or slightly cheaper now. A condender system boiled would have been 3k+ anyway.
- On an EV tariff which doesn't strictly require an EV, you can auto-program your ASHP thermostat to pump as much heat into your building as possible in the cheap hours, whereas you don't have a cheap gas window. If you want to do this, look into adding a buffer tank to your ASHP install too for a bit of extra thermal storage.
- EV tariffs are a double-edged sword, and only really become cheaper if you have Solar to supplement the expensive day-electricity. Otherwise your day cost will most likely outweigh your night cost, unless you have an EV to charge.
- If you do have an EV AND and heat pump AND a battery and you want all those things to charge in the cheap tarriff window, and you might have a tumble drier & pool heater if you're posh, you might need 3-phase depending on what your EV charging rate is.
- ASHP install will need to be part of an unvented, mains pressure system. If your house is currently gravity-tanked, you need to add the system upgrade into the cost. Mains pressure showers are so worth it, and the hot/cold pressure being balanced is amazing.
- ASHP will drain the battery very quickly, depending on what it's doing. For easy maths, a 10kwh battery will be drained in about 4 hours when maintaining heat in a 4-bed average UK house with other things on. When it comes to battery, my belief is go big or dont bother. 16kwh+, you really want to to last 24 hours if possible. And have more than 16a charging capability so it can be charged full in under 4 hours in the cheap EV tariff window.
- I think ASHP + battery + solar is the full package where it all starts to make sense and be greater than the sum of the parts. Otherwise, your returns might be slower/never happen.
Good points
One point with that lessens the benefit of your suggestion to run the ASHP in the cheap time slot which is going to be at night. That's when outside temperature is likely to be lower, is not lowest, so you are driving the ASHP at its least efficient.
If you've already paid for the ASHP yeah, use it.
If it's not yet installed then do the comparison vs using resistive heating (dearer to run but bobbins to install) and vs using traditional electric storage heaters (that stored the energy as heat).
It's not obvious to me which would be better. It seems fairly obvious that no one mix is best for all cases
@@trueriver1950 The real world difference in efficiency with ambiend temp difference of 10c is quite small, maybe around 20%. But the electricity rate is about 4x cheaper, so it makes sense to use that time window to it's maximum.
Resistive heating would be much much cheaper to install (and heat pumps need an annual service ideally), but a few years down the line ashp will be winning.
Actually, in January 2022 our ashp broke down and we were forced to used in-tank immersion heater for hot water and 3 oil radiators, 2 resistive space heaters & a halogen heater for around 3 weeks. The house was still cold & our electricity bill was around £270 at 18p/kwh Jan prices. That's around 2.5x as much as with the heat pump & a toasty house.
Author is using the most optimistic figure for airsource heatpump efficiency, you will only get 3.5Kw for every 1 Kw used by heatpump in the summer at 25deg C ambient or higher ( when you need the heating least ) - but in winter at >10 deg C you will get nearer 1.5Kw of heat for every 1Kw of power into the heatpump - this makes the battery even more attractive, and much less disruption to you house.
Thank you!
Hi, very interesting analysis however you calculations seem a little bit off. You refer to the running cost of you EV as a saving, however that night time saving to charge your car would be there even if you choose to do nothing other than set the car to charge overnight, so really shouldn’t form part of the overall calculation when talking about battery installation. How on earth can you say that the night time tariff isn’t worth using unless you install a battery that’s totally wrong as your main saving is in charging the car and not the battery. Your costings have to be base only on Charging the battery with cheap rate electricity and under those circumstances the payback period would be much longer. Just one other point people always talk about payback, I believe there’s more to it than that, it’s also about burning less dinosaur juice and the fact that having fitted a battery, solar system, and heat pump one’s house goes up in value. The investment isn’t lost just parked until sale time.
Thanks, agree that burning less oil and gas is important but most people won’t shift to electric power until the costs come down
@@RealLifeArchitecture ... I think the COP of 3.5 for the ASHP is overly optimistic as well.
I agree with poster wobby, the comparison would have been clearer if you had left the car out of the calculations.
It's comparing apples with oranges; the heat pump has no impact on the car.
It makes the comparison a bit muddied, and harder to contemplate for those without EVs.
As you're using so much power to charge the car would it not have been worth switching to flex rate electricity and charging car overnight anyway even without a house battery?
Thanks for the eye opening vid anyhow!
Regardless of the financials a heat pump is only a boon if it is well designed & works effectively & efficiently and can get your house up to a comfortable level of warmth in winter. Not all installs will deliver that outcome.
several factors come into play.
the guilbility of the buyer
the mortgage of the seller
the quality of the equipment
the build of the house and insulation
the quality of the design
the quality of the installation
for the vast majority of UK housing stock only 3 words make real financial sense
insulation, insulation, insulation . Stopping heat transfer is the most energy efficient thing anyone can do.
Great Video! as a Givenergy installer in the UK I always get asked this question about heat pumps so thanks for making it so clear.
No problem
Love the fact that you provided very detailed numbers, in terms of kWh instead of just costs (which are too variable these days).
I have a few questions regarding your battery savings:
1. Did you factor in the round trip efficiency of lithium batteries? - My understanding is that it is about 95% for DC to DC, i dont know if there is more losses converting between AC
2. Did you factor in depth of discharge? Typically doing a 100% discharge each day is pretty stressful on a battery, even lithium. And will typically drastically shorten lifespan (based on mobile phone wear atleast)
AC to DC to AC is approx 12-15% conversion loss
@@MagicianMan ok, so factoring that in, wouldn't the battery savings then be at least 12% lower.
@@basildza The author is using the most optimistic figure for airsource heatpump efficiency, you will only get 3.5Kw for every 1 Kw used by heatpump in the summer at 25deg C ambient or higher ( when you need the heating least ) - but in winter at >10 deg C you will get nearer 1.5Kw of heat for every 1Kw of power into the heatpump - this makes the battery even more attractive, and much less disruption to you house.
@@chrissmith2114 I wasn't referring to the heat pump part at all. Was only asking about the battery savings calculation.
@@basildza That's OK, just pointing out the massive miscalculation of the article on heatpump expected output as well. which makes the slight error in battery look small compared. The truth is that heatpumps efficiency drops massively in colder weather, something the makers and the government are not keen to tell people.
Neil: Your analysis illustrates the 'problem' with heat pumps that not everyone understands: the difference in gas and electricity prices (while it remains) does not make heat pumps significantly cheaper to run than gas boilers - never mind the considerable up-front cost, which is why I think gov't grants for heat pumps are crazy when that money should be use to improve insulation. Furthermore, the reported dearth in heat pump engineers may (?) mean that the annual service to keep them running efficiently is rather more expensive than for gas boilers - something that no-one ever mentions when I read articles about HP use. For a start, if affixed up a wall, requiring a ladder to access, that, apparently, immediately adds to servicing cost of some £30-£50! Would you know what an average annual service costs? I bet it's more than for gas...
I take your helpful point about battery storage. Perhaps there's one caveat: that as more people charge EVs using night-time rates, as well as for battery storage, will that cost difference reduce over time? Much like gov't incentives to buy EVs have all but disappeared now that more have them, will 'night-rate' elecy go the same way? I guess we can only speculate...
Thanks for your useful analysis. I have solar but no EV. As a lower elecy user storage makes no sense for me given the payback time. An EV would likely change that.
Perhaps one should add (the obvious?) that so far as I read, while solar/battery is not now thought to damage property sale price, the investment is not thought to enhance it much either (as an architect you may know more, but estate agents venture this opinion), such that if there's a reasonable prospect of a move in the next several years or more, that should cause pause, albeit that as elecy prices increase the advantage of money-saving tech will be more attractive to potential buyers.
I always thought thr heat pumps were an expensive waste of time, I would like to get off gas and use storage batteries but then I need to convert my combi boiler. It's a huge nightmare, not sure what is best to do, at the moment I plan to not turn the heating on at all, I'm not paying £500 a month
I suspect millions will be in the same boat this winter
thank you, I will be making a follow up video in a few weeks time. All these points will be included.
Also a self employed ARB architect (I resigned from RIBA after 30 year membership in disgust at what has happened to the Institution). The coefficient of performance you quote at 3.5 for the ASHP is EXTREMELY optimistic, even as a maximum value, and would only ever apply when it is warmer outside than the latent temperature inside. When it is colder outside, there is literally no heat to be gained from the environment and you are working 'compressor only' and therefore have very expensive electric heating. ASHP in the UK are 'economic' for very short periods in spring and autumn. Also, just like the former 'green new deal', government funding is only available by using 'approved installers' who's costs are higher than non-approved installers, so once again the apparent subsidy is enjoyed more by the installer than the consumer. 'Payback' for ASHP installation is likely to be beyond the useful life of the equipment. The significantly larger radiators required lose wall space. I have recently reluctantly facilitated a whole house refurbishment with ASHP, but only on the basis of UFH at both levels (and my thoughts on UFH on a timber suspended first floor are from bitter experience still cautious despite using what at first reports seems to be a good product from Celecta) and solar electricity generation and battery storage to feed the compressor. All in, the changes to the floors, the ASHP and the solar with battery have added some £45k to the project which I fear will never be offset in use.
Edit: I nearly forgot; with two rapid EV charging points along with the ASHP, Western Power determined the property needed to be upgraded to 3 phase which meant pulling in a new cable up the drive!
Thank you for sharing. I am now loosing patience with clients wanting to explore ASHP options, wasting time until the penny drops that it’s a deeply flawed technology. Its only use is in new builds, at least until the price drops substantially and people can use one with a gas boiler as a backup
Very valid point about the SCOP rating being optimistic. My Mitsubishi Ecodan 11.2kw is rated at around 3.34 and higher. Real world is nowhere near that. Closer to around 2.5 throughout the year. Really depends how much water you're heating, as this temp differential is what hurts the overall efficiency stats massively. The best COP numbers happen at very small ambient/indoor temp differences - which are times when heating isn't really necessary, late spring & mid autumn. These are what make the averages look better.
My friend is an architect and now seems to want to work abroad all the time. His family and I dont really see him as much now but he did mention RIBA being a factor this year.
Why is it so badnow? Whathas changed?
Cheers n stuff
Leigh
A bit of misinformation on ASHP - this is not correct; one fact though is that UK "Approved installers" are charging over the top amounts, ASHP's in the UK are overpriced and are indeed barely worth it due to the suppliers and installers abusing the UK people. Outside of the UK however, ASHP are not a deeply flawed technology. My mini split (Still an air source heat pump, same tech) has a real world SCOP of 4.9 at 15c and is still well above 3 even at -5 degrees. The tech isn't flawed, UK businesses making record high profits on what I can only describe as mediocre installs is.
@@velianlodestone1249 Congratulations; it appears you have successfully broken the laws of thermodynamics.
We've had 10kwh of batteries since April, based on their discharge readings they've saved us about £600 so about £100 per month. That does include some charging from solar but it's mostly overnight. Total cost of the system was about 11k so it's returning about 10% per year but I think if we'd just got the batteries we'd still get most of the saving
I’m going to do the same eventually
Hi, just out of curiosity, which company did you use for the solar and a 10kwh battery.
I think you ought to have included a 3rd scenario here which is installing the heat pump but switching to the dual rate electricty. You still get that 1000 saving on the car, even without the a battery. If you install a water cylinder large enough for a day's usage then it can be heated on cheap rate overnight. Your home is well insulated so you could at heat it up overnight on cheap rate (using the last few hours probably best) and lower the temp during the day when it's less cold outside anyway. You'll probably have to use some heating between sunset and cheap rate starting up but this could be kept to a minimum. Most of the year you probably won't need much peak rate heating except when it's very cold. Your water heating could be on cheap rate all year. Depending on how much other electricity you use during the day and what time your cheap rate starts etc I would expect that you would save money overall by switching to dual rate, especially given the huge savings charging your 2 cars.
Probably true, I will be making a follow on video in a few months and will look at this further
I was wondering exactly the same thing. The £1000 on the car would seem to be the clincher.
One thing I was wondering though - as an ASHP uses heat from the air, that external air temperature will be colder overnight, so the heat pump will have to work harder than it would during the day, to heat a given quantity of water to the same temperature. Does that temperature difference offset the savings of running the ASHP in the cheap rate period?
@@davidy7004 how much difference it makes depends on how hot you are having the water temp, as it is the difference between the air temp and water temp that is key. If your hot water is going to be 65 and your flow temp to get that is 70, then if your air temp changes between 15 and 5 then that would be either 55 or 65C difference. So night time is 18% bigger temp rise in that scenario. I think energy usage is a bit worse than linear so maybe it's 25% more electricity. But the night price was less than half the single rate price so it's still much cheaper. The problem with switching to dual rate is that it makes the day price higher than when you are on single rate so you have to watch out for that, especially if your heating is electric.
@@adrianthoroughgood1191 Thanks for that. - very interesting.
Thinking about it tho, for just hot water it would be more efficient to just install the hot water cylinder and heat it with an immersion heating element during the "low cost period" and not bother with the heat pump.
From the research Iv'e looked into, the next step up is a "Zero Emission Boiler" as the way forward. They are basically a big thermal battery' with much higher energy density than just heating the water directly. You charge up with an electrical heating element and then use to heat you water on demand like a conventional boiler.
So the same principle as charging at night and consuming in the day.
You also have to consider the fire hazard a battery holds. If it malfunctions and starts a thermal runaway youll have a hard time stopping it and depending on the position its been installed a 30/60min firewall wont hold it back
Good video, I'm am electrician and engineer who lives in Finland and has a ground source heat pump with underfloor heating. As you might imagine we have very cold and long winters. My house is 205m2 and we only use about 12000kwh per year. That's everything, heating, cooking, cleaning and lighting. The main thing what has to change in the UK is the insulation levels of houses. Given your average temperatures there is no way it is necessary that you should be using that much energy to heat that size of a home.. my home is also 20 years old.
Also one thing to consider with batteries is their life span. They will most likely need replacing after 10 years. This of course depends on the battery type and conditions, charging controller etc
Thank you. It’s always great to get a perspective from somewhere different. I’m not sure about the battery life, time will tell
Lifepo4 batteries are generally rated at 10 years if you completely discharge them every day. If you only run them down to 80% then the charge life will double, and then you're into death by calendar date rather than by battery life.
one thing to consider is future expectation of prices. Gas is supposed to significantly increase this year and medium term may tilt things towards ASHP. Also if you had a battery too - your ASHP can benefit from the cheap rate (although you’d need a big battery..)
All true, but I still think ASHP need do drop in price by several factors to make them worthwhile
@@RealLifeArchitecture Do you think ASHP will actually drop in price though? Unlike solar, where panels keep getting more efficient and material costs per kWh keep coming down. Most of ASHP cost seems to be in the installation, which is a service and typically only goes up. And running costs is limited by physics and will stay proportional to the price of energy.
I like your videos, but in the real world, pensioners like me who live in an ex council house, over 120yrs old, don't "heat our homes", we heat a room that we are in , usually the living room. The rest of the house is freezing and getting covered in mould. We compensate for this by walking around the house like a polar explorer, during the winter months, dreaming of the coming summer, when it gets so hot we think we are going to die of heat stroke, because buying an air conditioner is a dream too far. I am looking at this video, because my gas boiler has given up the ghost, and I am looking for a solution to my "no hot water situation" It looks like I will be going for the more local electric heating, such as instant electric shower, and similar hand wash instant water boilers over the sink, and perhaps a portable small electric radiator, upstairs, and one for downstairs. So much for being self employed for over 50yrs, and never claimed any so called "benefits" in my whole life. If anyone reading this is considering self employment, think again, do yourself a big favour and go to work for a large company, with all the perks .
Thank you for this analysis. I have storage batteries and am very close to off grid full time. You touched on a very important point. Let me explain.
I do everything I can to control when I purchase energy from my utility. For example, most of my power tools are battery operated, this allows me to charge batteries when the sun is out or off peak times when energy is cheaper or my house batteries are full, just like you do with your EV. My EV charges during the day, again when the sun is out or in your case at night off peak. My vacuum cleaner is a battery operated robotic vacuum that runs when we need to clean but what's important is that I CONTROL when to charge it.
What you want to do ideally is be able to control when you use energy. Our water heater is tankless, this might raise some eyebrows but, again, I control when to use hot water. All our small usage like hand a dish washing doesn't tax the PV even though the tankless is wired for 20kW. You only use that amount of energy when it's at full house flow rate, several people showering, washing machines going etc. At our shower rate of 1.5 gpm it only uses ~5kWh which the batteries can cover. If we shower when the sun is out the PV covers the requirements of the tankless, off hours , no sun the batteries do. You would think that 5kWh is a lot for the batteries but it's not. Here's why: I take 4 or 5 minute showers which is about average for people but let's say I took an 8 minute shower. 8/60 x 5kWh = 666 watts to take a shower. That's easy for the batteries and inverters to cover.
If we had a HPWH then we couldn't control when it heated water so it would cost more in the end, worse there are standby and line losses that don't occur with tankless. I heat the house water to ~40C a HPWH heats water to 49C or more, that's wasted energy.
You get the idea, that's what you're basically doing with your EV, you are controlling when you use energy - this is the key to savings.
Thank for your detailed comment, you have clearly done the math. Your basic concept is a good one, if it can be measured it can be managed.
Most would be better using a point of source heater at the sink. Otherwise you use half a bowl of hot water just heating the pipes before any useful hot comes through. Or even more simple, boil a kettle
@@markthomasson5077 You can't shower with a kettle very well.
What you're talking about are line losses. Tanks have two types of losses, standby and line. Standby in tanked heaters is how much the temp drops relative to the room. Line losses are from the tank to the fixture. The simple solution to line losses is lower volume lines, I use 3/8" insulated Pex to my fixtures so the line losses are almost null. On a tanked heater the water must have a minimum temp of 120°F(49°C) but even at those temps legionella still grows that's why commercial installations must run 140°F(60°C). There are great standby and line losses at those temps then you have to take that high temp and mix it down to usable.
With something like a tankless you set your temp to the working temp so the line differential is much less and there are no mixing losses so unless you have a very long run there are minimal losses from the tankless to the fixtures. A 25' foot run with 3/8" Pex is only a cup or so of water so it's moot to have POI at every fixture. I run 105°F (~40°C) to my shower and since there is no tank for warm water to sit in no bacteria problems.
If you have a big hot water demand HPWH is better but for a one to three person house tankless works out better. My one to two person house uses less than $5 a month at our grid rates running tankless. This high load tankless is a myth,. unless several people are showering at the same time you're using very little energy. A five minute shower at a load of 5kWh is only 5/60 x 5e3 = 417 watts then the water stops and no current is drawn. Hard to beat if you ask me. I monitored my heat and mini split for a month. I used 31kWh for hot water and 270kWh to heat the great room (25'x25'x14') from the middle of Nov. to the middle of Dec. that's $27 to heat and $3.10 for hot water. The PV covered both. If the outside temps rise to over 40°F (4.5°C) the mini covers the whole house, on really cold nights around 15°F(-9.5°C) and below I light a fire in my high efficiency fire place and with the mini I'm good.
This is just the explanation I was looking for as I've been considering these as well. It would be useful to know what difference solar panels would make, as I have them fitted already, and considering adding more.
It's sad but true that the consumer comparison is so often "how much money will I save" and not "how much carbon emission will I save", whereas the government funding is looking at the wider social cost of the carbon emissions. That said, I would definitely do the solar + battery as the first stage - possibly over-speccing the battery to help keep the cost down when you do the second stage and install the heat pump.
It the way of the world. EVs didn't become popular until the costs came down, it will be the same for ASHP and batteries.
Hi Neil,
Did you check out air to air heat pumps. You can get a 2.5 kW one for about £600. They are simple to install.I guess installation would be about £600.
You could then run it at night To provide a Minimum temperature says 16°. I know this would be forced air so unless the building was moderately air tight , you might lose quite a lot. The added benefit would obviously be air-conditioning in the summer.
I have installed these myself to anyway you Cant put a gas boiler.
Really interesting comparison. I've got battery storage, 2x Givenergy 8.2KwH = 16.4, with 5.6Kw of PV panels on the roof. Total installation cost 2 years ago was £12k. Also have an electric car that either gets charged from the solar generation or overnight on Economy 7. Only drawback with the system so far is that the inverter has a max input/output of 2.5Kw. However, I believe the latest inverter from Givenergy can do 3.5Kw. Perhaps you should add PV panels to your comparison? Did you consider a ground source heat pump?
That is my plan
I love the fact people worry about the payback period. When we renewed our kitchen in our last house the question of a payback period never came up because we did it to suit us. If you can afford to stop burning gas, coal, oil or whatever then do it. If you use a lot of electricity then a battery makes perfect sense especially as an EV owner plus you can now get EV tariffs and charge the car and battery at 7.5p per Kwh.
.
Unfortunately money matters to most people. Renewable tech only gets going once cost/benefit gets to a certain point. It did this with wind and solar, it’s getting close with batteries.
Thank you for such a concise professionally detailed and edited video with visual price explanation (Genius). On Top of your 8.2kWh system saving ‘your’ systems £1,428 a year (with a break even of 3.47 yrs, you would also save a further £9,390 for the first 10 years or £23,770 for the first 20 years, after payback/breakeven or factoring in any future price increases. If you have solar and end up generating excess energy, saving this to your battery far out-ways any pay-in tariff and makes this figures even greater. PS There would potentially be some battery degregation over time. WELL DONE
Battery degradation may be an issue over the very long term, for sure. Adding solar to the mix would be interesting but I opted not to include this in the video because everyone’s house and climate is different, so the effect would be too varied.
@@RealLifeArchitecture Not only battery degradation, but also inverter replacement is often overlooked.
I think they guarantee the batteries for a set amount of time. Can't remember if it is 10 years though.
@@daviniarobbins9298 to put it in context, our 2014 Tesla S uses the non LFP cells (that last for an insane amount of charges LFP is lower power but 5 times longer lasting)...mine are the standard 18650 lower cycle cells.... we have done nearly 170k miles in it and have lost about 7% range after 8 years. Solar is much kinder to a battery than asking 350Kw from a car at times. 100A is 5,000 watts ...nothing to a large solar battery that shouldn't really be discharged to zero too many times if you've got the calculations right. I aim for 20% at least left by morning and charger to around 90%
I have just installed a heat pump via Octopus Energy. I agree this isn't going to save much on running costs but initially I am doing this for carbon reduction . It has cost me £6k and includes replacing 11 of my 14 radiators. My boiler was due to be replaced so I would of spent maybe £2.5k ish anyway and our old radiators were a bit rusty and dilapidated. I have an Electric car and solar panels which is already saving about £900/annum overall so the next step will be a battery which will also help to reduce cost of running the heat pump a bit using cheap night rate electricity and maybe some solar that we currently export in the autumn and spring months.
Thank you, the figures you quote seem to bear out my calculation.
Put your washing machine on timer mode and timeshift it to the cheap period: that's about 2kw a day you don't want your battery to have to supply.
Also get solar if you have a South or east facing: it just takes a sunny morning and that 9kwh battery will charge to full from around 20% by lunchtime if you can fit even a 3kw system (like mine), meaning if you keep an eye on a solar forecast you can get away with only charging to 50% overnight way more often than you'd think.
Without solar yeah - just charge to full every night, but consider keeping an eye on your usage patterns and setting it to discharge only at certain times or avoid others: the oven will suck huge chunks out of it, for instance, and you don't want it therefore going flat right before you start cooking, because thats likely 3kw or so which is a significant percentage of your daily usage, like the washing machine, but it's something you simply cannot timeshift to the early hours.
Slow cookers and air fryers are also your friend with a battery, especially slow cookers.
Laptops + external monitor and keyboard/mouse are better than desktops.
And so on: you want low constant draw more than you want big hits. A dehumidifier rather than a tumble dryer (unless you have a suuuuper efficient tumble dryer but then you're an architect you can probably afford one of those and a house big enough to fit one lol! I... Do not).
The exception being your kettle, unless you want to get a caravan kettle and wait five minutes for boiling water, that's an inconvenience too far for us :)
I've no idea about the heating options I'm still thinking about them, but I figured before I electrify, I should look at generation and storage, so as to be able to have money to save for the heating and water.
So far... Yeah it was definitely the right decision.
I don't really know why the govt aren't providing grants for my kind of set up, if not just doing it at scale - I did some quick maths last night and assuming there were no savings from economies of scale it would cost 16billion to install 32gw of solar and battery storage - only 1 billion of that is panels - and take up only 1m square metres which is about 8 X 100m X 100m space per county in England, far less if we include all of UK, which of course we should.
There must *easily* be that kind of suitable roof space in the UK.
Provide the 5k grant for up to ~10kwh battery storage per household, space permitting OR towards a heat pump. Or other generation/insulation/storage systems. Now is not the time to limit options not with our housing stock!
Anyway, the money is 5k up to 30k houses per year for 3 years: a mere 90k homes and a mere 450million over 3 years.
So spend 1bn more and give over 8 x100m square space per county to solar farms, and pump as much money as possible into whatever grid storage systems are cheapest per watt at scale, and let householders pick up the best energy saving/generation/heating/storage options work best for them.
Aaaaaaaaa frustrating!
ANYway: Please start designing space and physical support for all this kind of stuff, if not designing it in in the first place. If govt won't legislate it's up to firms to just... Do it.
...er.... Bit of an epic comment. Enjoy the rest of your bank holiday Monday :D
That has to be the most epic comment yet!
I am run off my feet with the day job just now but will get back to you in due course with a suitably epic response.
I'd add to that list: electric pressure cooker (eg instant pot). Super efficient because they're insulated, only need to be on for a short time and don't waste energy as steam (which you therefore don't have to dehumidify or vent away). Another benefit is that you don't have to plan anywhere near as much as with slow cookers!
@@RaglansElectricBaboon you are probably right but I have bad memories of being fed tasteless mush from pressure cookers in the 80’s plus, I have two boys of my own who are fussy eaters. I wonder how a pressure cooker compares to a casserole, in energy usage terms.
@@RealLifeArchitecture garbage in , garbage out. If you don't put flavour in you won't get it out :-P
Instant pot is rated at 1kW and takes about 15 minutes to steam/boil cook potatoes. It's not on continuously for that time but does need to heat up first. So about 250Wh for a load of spuds. I don't know about casseroles but seeing as the instant pot can do slow cook as well I reckon there's some sciencing to be done. Get your two boys onto it!
Thank you very much for your work. I live in Eastern Canada (Quebec). Hydro Quebec is promoting a package which consits of a heat pump combined with heat storage unit within a forced air furnace. Am I wrong in assuming this is a very appealing combination? The utility 's goal is to eliminate the burning of fossil fuels. Thanks again.
Thanks for getting in touch, I love hearing from people in other parts of the world. Forced air furnaces aren’t something I am familiar with. We are just beginning to look at heat storage units in the UK. Things are starting to change, slowly.
Thanks for sharing, the numbers stack up for your circumstances, have you considered PV and battery at the same time? You would save the VAT doing them both together?
I would add that your electricity consumption even without the EV seems rather high - have you looked at reducing this first?!
Solar panels on the way
3.5 gain on your heat pump is very optimistic. When temperatures are below zero expect no better than 2 times. This is why they should only be used in very well insulated houses that already use little energy because direct electrical heating will be used if the heat pump output drops too low.
Thanks, this point has been addressed in the pinned comment.
Really helpful and looks like my decision to install battery and solar was the right one. You might also look at Tepeo an electric system which replaces a gas boiler without having to upgrade radiators etc but works on the same principle. I don't kniow the price. the everything electric show youtube channel had a video.
Thank for the tip, I had not heard of Tepeo but I looked and it seems promising.
I am currently planning a new build 4 bedroom bungalow and I am researching both Air and Ground source heat pumps, both have their advantages. I was quoted £13.2k for air source which included a 100L and 250L water tanks. The calculations say a saving of £878 per year. I am also looking at solar, the property will have 3 phase power so the Giv energy is no good, there are some 3 phase systems which will cost about £11k with batteries and PVs.
Thanks for giving us those figures, very useful info.
Interesting Topic and your correct that a battery set up will be more beneficial than Ashp . Your Ashp will almost certainly not provide the cop you quoted. Add solar Pv to your battery set up and your savings will be even more . The government hasn’t thought this push for Ashp through properly and despite what’s being said I believe the gas boiler will remain. Tests are already underway in the Uk where they have added a small percentage of hydrogen into the gas and this has had the effect of bringing down emissions to almost zero which is the main goal. Worcester and Baxi have already began manufacturing hydrogen ready boilers. Instead of rushing in buying electric cars , Ashp etc … I would suggest waiting 2 or 3 years and see what develops plus I wouldn’t base buying batteries on the premise that cheaper nighttime rates will always be available.
mostly true but I think the EV tech has matured to the point where they are ready for mainstream. It's the public charing that needs to catch up.
This is a well thought out video however there are some further understanding and calculations regarding peak power and use curve you need to consider. I know this as I followed a very similar process before installing a ASHP, solar and batteries.
Your battery output is limited to your inverter output and battery discharge rate. If you exceed either of these figures you’ll draw from the grid even if your battery has change.
For example. Taking the givenergy system you mentioned, the inverter has a max discharge capacity of 3.6kwh and battery 2.5kwh the most you’ll ever be able to draw is 2.5kWH at any specific time (according to Givenergy).
So, you come in after work, you turn on a few of your appliances, kids doing the same and whilst you’ve got the cooker and Kettle on you’re drawing 4kwh. 2.5kwh from your batteries and 1.5kwh from the grid.
At the end of the day you’ve used 10kw but only 6kw from the battery.
The second issue already alluded to is battery utilisation. Your calculation assume full utilisation of the battery. Whilst you may be using more than 8.2kw a day, if your peak energy exceeds your battery delivery ability you may not exhaust your battery thus making it less efficient.
So, you need to understand not just your energy use over time but also your peak energy curve and ensure your system matches it.
For example, if you find your do exceed 2.5kwh at any time you could fit 2x 5kw batteries and a 5kwh inverter allowing you a max discharge rate of 5kwh. This however costs more.
The only way I could get the numbers to work was to install an ASHP, solar and batteries. The heat pump was a 12kw, 20kw of batteries with 8.6kw of inverters and 6kw of solar. I had to pull in a few favours and accounting for government insensitive my projected energy costs including investment should be between £1500 and £2000 for a large 5 bed house. Investment cost written off over 10 years.
HTH
Thank you for your detailed comment.
Thought I’d add my situation, I’ve and east west solar setup with a Powerwall a Zappi car charger and an Eddi that diverts solar to heat water. I’m also fortunate that I got in when FIT payments were about to be fazed out so I also get about 8 p per kWh generated with amounts to around £400 a year. The Powerwall holds 13.5 kwh of energy that’s charged up during the winter when there’s little solar, on night rate electricity currently, 7.5p per kWh. That is usually enough to see us through the following day. Before the current crisis our total gas and electric bills, when all was taken into account was near to zero. That’s allowing for the FIT payment and the estimated amount I spent each month on diesel that I no longer have with our Kia Nero EV. During the summer months our car is charge up on excess solar energy.
Hi Neil, I’m coming to the same conclusion myself… the heat pump is more about saving carbon reduction than money. Just wondering why you haven’t bothered with a dual tariff for the EV before?
Because both my wife and I work from home, our daytime use is such that it would offset or exceed the off-peak savings
This is a really good video. It clearly makes the point that ASHP only reduces the heating/hot water costs. So many ASHP evangelists never mention the sky high electric costs. I deal with all forms of boilers/ASHP/Solar etc and the bottom line is there is no silver bullet that solves all problems. Ideally we could have solar feeding battery storage and then the heat pump but you just need several days of poor sunshine and you are in trouble again. In the current economic climate, the main reason I'd have for installing a heat pump is for cooling during the summer months. This is becoming a big concern in the UK, especially for homes that are well insulated for the winter but have poor ventilation during the summer.
True
Superb techno-economics Neil, always straight to the point - many thanks
👍
What is your method of heating in the battery storage case? I may have missed it. I see that it needs either electric resistive heaters or heat pump or electric boiler of some type (e.g. ZEB). What is the installation implications for this as I understand your house currently uses a wet system.
Great video to see your calculations. I find this subject challenging and there must definitely be space for some honest, independent, online comparison tools using input such as current gas/electric usage, number of radiators, square meterage of house, etc.
I look forward to your update which will apply some of the missed factors raised in previous comments.
I assumed either battery or ASHP in the calculations. If I got a battery I would keep my gas boiler.
Certainly one of the best videos I have watched on the subject. 🙂There is a lot of greenwash and grossly unscientific discussion on you tube but this is not. (and I am well qualified to know the difference!)
Thank you
Great vids. I think if you could factor in the cost of adding solar cells to charge the battery during the day and adding a grid tie system to sell on extra generated solar power to your electricity supplier, it would be interesting to see the cost and savings.
True, but adding solar costs more and is location specific
If you install solar and a battery, the solar is mostly going to replace the cheap night-time power that charges the battery. i.e. it's only generating 10p/kWh. If you do export any, it will be lucky to earn 5p/kWh. Export rates are very low now the subsidies have finished. If you just look at the hardware costs, you'd get about a 10 year pay-back. Installation cost varies widely depending whether you can do it yourself or need a load of scaffolding, but it might push it up to a 20 year pay back. OTOH, every time electricity goes up, that pay-back period will get shorter.
This is a well thought out video however there are some further understanding and calculations regarding peak power and use curve you need to consider. I know this as I followed a very similar process before installing a ASHP, solar and batteries.
Your battery output is limited to your inverter output and battery discharge rate. If you exceed either of these figures you’ll draw from the grid even if your battery has change.
For example. Taking the givenergy system you mentioned, the inverter has a max discharge capacity of 3.6kwh and battery 2.5kwh the most you’ll ever be able to draw is 2.5kWH at any specific time (according to Givenergy).
So, you come in after work, you turn on a few of your appliances, kids doing the same and whilst you’ve got the cooker and Kettle on you’re drawing 4kwh. 2.5kwh from your batteries and 1.5kwh from the grid.
At the end of the day you’ve used 10kw but only 6kw from the battery.
The second issue already alluded to is battery utilisation. Your calculation assume full utilisation of the battery. Whilst you may be using more than 8.2kw a day, if your peak energy exceeds your battery delivery ability you may not exhaust your battery thus making it less efficient.
So, you need to understand not just your energy use over time but also your peak energy curve and ensure your system matches it.
For example, if you find your do exceed 2.5kwh at any time you could fit 2x 5kw batteries and a 5kwh inverter allowing you a max discharge rate of 5kwh. This however costs more.
The only way I could get the numbers to work was to install an ASHP, solar and batteries. The heat pump was a 12kw, 20kw of batteries with 8.6kw of inverters and 6kw of solar. I had to pull in a few favours and accounting for government insensitive my projected energy costs including investment should be between £1500 and £2000 for a large 5 bed house. Investment cost written off over 10 years.
HTH
If you don't have an EV solar panels and storage are a massive win at the moment. Agile export rates are as high as 18p throughout the entire day so a reasonably sized solar array (6kwp) can easily provide entire house consumption, charge battery storage bank AND also export to grid at around £3 per day. A heat pump wont be doing much during the summer months, whereas the PV and storage can generate money beyond the SEG.
True
@@RealLifeArchitecture an update on this. Export rates are as high as 80p a unit now and every slot in the entire day export rate is above the import rate.
Air to air heatpumps, AKA Aircon, are much cheaper to buy and fit than air to water HPs. There is minimal disturbance because no new rads have to be fitted and you get cooling on hot days. Air to air is more efficient too, because there is one fewer heat transfer process. No regular maintenance is needed either. Downsides, which no-one talks about, are low level noise, no hot water, and the de-frost cycle which periodically sucks heat from the house to clear ice from the outdoor unit on cold humid days. Aircon works well with solar pv, providing cooling at zero cost during the day. Battery storage can return the free solar electricity at night to give cool bedrooms. Aircon already benefits from the economies of large scale manufacturing. It is only the Brits who seem to be stuck in the past with water based systems.
Probably true but, as you pointed out, it’s almost unknown in the UK. I’ve been in homes from 1970’s with air heating and they have a lot of ducts built into the floors and walls. Retro fitting these won’t be easy in older properties.
Really good vid thanks, clacs were really spot on, if you added solar to charge the battery during the day this would reduce your electric bill a better way although the initial cost is roughly 6k for 4KW decent system with microinverters
Solar is on the way.
You would save a good chunk of money just by switching energy tariffs to day and night rates regardless of having battery storage.
Most EV owners are on these tariffs as it in pretty much all situations saves the bill payer money if they’re charging cars at home.
As for the ASHP, you didn’t factor in the savings made from removing the gas meter which at your standing charge will be around £100 per year. Or the savings you’ll make in maintenance as ASHP require much less than gas fired boilers.
All in all, battery storage is the better option especially if you factory in solar PV panels. You can even sell excess energy back to they grid at higher rates if you get the correct energy tariffs.
True, and I will look into this further in a future episode
Of course the downside of ASHP's is the lifespan won't be as long as a gas boiler and any repair bills will be way way higher. Gas boilers sit inside in a nice warm house.
ASHP'S sit outside and work in the worst environment.Cold wet dreary weather. Worse they are expected to work harder the worse the weather gets. This has a serious effect both for efficiency and importantly durability. If you honestly believe this "20 year lifespan" nonsense oft touted I have a bridge to sell you.
All the savings will be wiped out very quickly and you will be staring at dark red ink when looking at whole life costs.
I've been in the air conditioning industry since 1982 to date and believe me, whilst equipment is more energy efficient most of the progress has been making equipment adapt to enforced refrigerant changes not for another reason.
One thing is for certain, those air conditioning units of 20+ years still chugging away are being replaced with units of a 7-10 year lifespan. Things ain't wot they used to be quality wise.
On the upside, there are several potential upticks in efficiency on the horizon including vibrating compressor technology and molecular electronic heating which will up the COP but for now I'd be very cautious on splurging vast sums on equipment thinking you'll save in the long run. Chances are that's possibly a very costly mistake. 👍
I'm looking at both of these options, looks like for me battery and solar first. My only comment is that obvs you shouldn't subtract the EV overnight saving as this is possible without the battery. But even saying that, i would say with the current electricity costs you are looking at less than a 10 year payback for a battery.
Thanks for the comment. I will do an update later this year
Maybes if you were building a house from scratch installing a heat pump would be a good idea? Combined with a solar system and battery storage? I would install a better inverter though, say 6kw. An inverter that can handle up to 6kw in and out.
true
Thank you for a well laid out video... spoken in lay mans terms.. I have Solar panels with FIT...and was concerned which way to go in an older property... (1970's bungalow ).... the thought of going thro new radiators, replacing a gas boiler not even 5 years old etc etc.. and all the upheaval involved....... I spoke to several friends with batteries .and they all said it was batteries all the way...they had turned heating water / rad temp down to 55 degrees ,,, and were not impressed with the heating of the house...........No one I know has ASHP fitted ..These all seem to be fitted in NEW BUILDS with Under floor heating .with modern insulation etc............. . .SO...... I chose Batteries a few months ago and watching this video has made me feel " I've made the correct choice "..
Thank you for your feedback, it’s always good to know when I’m doing something right.
Just went for Solar 4.4Kw of panels with a 17.4Kwh storage battery - will continue to run a gas central heating system until either the price of Heat-Pumps comes right down or gas boilers disappear forever - the saving isn't there yet with Heat-Pumps & I'm also wondering about reliability 👍
I agree. Maybe in 5-10 years, with mass production and the economy of scale, heat pumps will be cheaper. They still won’t get over the problem of needing underfloor heating to work efficiently but if a pump costs £1k as opposed to £10-15k you could put a couple of them on your house and run radiators, backed up with some electric storage heaters / immersion run from off peak tariffs.
@@RealLifeArchitecture It's the additional cost (and hassle) of putting in underfloor plumbing for it to be most effective - most folks have radiators which isn't so good - maybe I'd be better with electric underfloor heating with already getting solar 🤔
Instead of water Heat Pump, I fitted two split Air-Source Air Conditioners and use these as heaters in Spring and Autumn, falling back to gas on very cold days. I heat Hot Water separately and the Air Conditioners work great as heaters and the benefits of cooling in Summer. Instead of £15k plus for Heat Pump, divert Solar to Hot Water and pay for the electricity in winter to heat it (I fall back to gas). £2000 for the Air Conditioners. Solar is free so although it takes longer, an immersion heater is a lot cheaper to buy. Other than that, a small eBay Water Heat Pump for £1500 will efficiently Heat water. Even at this, I can't justify the costs against what I'm already saving with Solar, battery, hot water and car.
Separated heating and Hot Water is key.
Solar PV can be added to a battery system. It's also been interesting to see a few people experimenting with solar air heaters and heat pumps.
True but every roof is different, I wanted to keep the calculations simple
How things might have changed with electricity price rises.
But My experience of using an EV tariff plus a an ASHP is that for 5 months of the year no daytime electricity is used for heating and hot water. And indeed for most of the year the heat pump runs hard overnight, lower COP because it is colder and the savings are much higher than your calculations. Pair a heat pump and a battery and charge your car overnight and it is a win, win, win situation.
What a crisp, to the point, full of facts, video with numbers based on real life products. Thank you Neal, just what I was looking for. I have solar panels but wasn’t sure if to get ASHP or battery back up. I see you have a Tesla, if not already done, I would like to see your review on its + & -. Personally o think Tesla needs a few years to iron out it’s done very basic issues plus I really despise and tablet stuck in the middle of the front dash. Thanks again for a fab video.
Thank you for the kind comment. I’ve had the Tesla over 2 years and love it. There are some things which annoy me but, on balance, it’s great. Check out this video on bidirectional charging ua-cam.com/video/Re3QkHhuG1c/v-deo.html
Good video, promotes thought! A few things missed. Depth of discharge is usually 80%, so really only 80% of the battery available or the batteries will degrade too fast. Losses in converting AC to DC for battery and the back again. Also 15kWh is a lot for two people you should be able reduce that quite easily, requiring a smaller battery. Time shift energy to cheap rate for high demand appliances, washer, dryer, dishwasher ,bread maker etc. Octopus Go are still offering 7.5p kWh cheap rate in Aug 22. That all being said, I have a 20kWh battery array going in next week to move 100% of my electricity to off peak 7.5p kWh. With peak rates moving to 50p kWh this winter that gives me a less than 5 yr ROI on a system that should run for 20 yrs. Using the monthly savings created back into an interest free loan paid for a new system gas boiler and immersion heater and moved them so in 15 years all ready to put in a new heating system. This allows me to move hot water generation to cheap rate high efficiency and off the 58% gas efficiency for hot water supply and using batteries to ‘top up’ hot water during the day. Finally adding 2.8kWh solar array to roof of our shed, cheap to install and reuses battery inverter during the day to top up battery. Allowing me to go longer without gas boiler central heating. At some point in the future when cheap rate is not as cheap will add another 8kWh to the main roofs.
Sensible, thank you for posting. 👆🏻👍
I need to do something like this, I have gas and electric so really need to do something. I have read soon a combination of hydrogen and gas will be used 30% hydrogen which will reduce costs massively but you need a boiler than can support the blend
@@leejohnson197733 the batteries are in and operational, the new boiler/immersion go in tomorrow. The new boiler supports hydrogen mixes, so if they do add hydrogen should be ok. Although, not sure how viable hydrogen is going to be given the massive, to the best of my understanding, amount of electric needed to create it. The rise in price of electricity and looking at 78p per kWh in Jan means the batteries will pay for themselves in less than 3 years so my gamble should payoff.
thank you, I will be making a follow up video in a few weeks time. All these points will be included.
You should mention that heat pumps act as a grid stabiliser. The more heat pumps there are, grid base load would be relatively higher and peak load lower - this would allow us to have cheaper electricity generation.
Alot of people forget that heat pumps are the often most efficient way to use ANY source of energy to heat a building. It makes more sense to burn gas in a power station to make electricity for heat pumps than to pipe it to homes to burn for heat. (A modern power plant is about 40% efficient after transmission losses),
10megawatts of gas procures at the power plant 4 megawatts of electricity
Electric resistive heaters would give you about 4 megawatts of heat
Burning the gas in the houses would give you about 9 megawatts of heat (we are very good at getting energy out of fuel on site) - so seems rational to do this... BUT.
If you use that 4 megawatts of electricity in heat pumps COP 5 you end up operation at 200% efficiency of the gas, a 100% bonus. Literally more energy than the gas itself contains ends up being put into buildings. You only need COP 2.5 to break even with on-site fuel burning, and COP 6 units work in most environments.
Thank you, I hadn’t thought of that. Very good point
That was very interesting and potentially useful.
As you mentioned in your pinned comment #4, the off-peak tariff is no longer offered by my supplier, which might have helped us as our son has an EV and we also have a garden spa (sounds posher than hot tub!) which could use night time electricity for heating.
We are having a stand alone wall mounted air conditioner/heat pump fitted for summer comfort and winter heating supplement- our normal heating is by gas boiler & radiators with a gas fire that can also be used in the event of power cuts.
Have you had any advice on the maintenance costs and battery life? I also have great concerns about the robustness and spare part availability of control systems- I have noticed a worrying trend of recent electronic failures. In the last few years since we had smart meters installed, 3 have failed with another that failed during its installation. We also had to replace an oven due to a burned PC board- never had these problems with British made ovens-our Creda with eye level grill lasted fault free for 27 years.
Ive been told that batteries like the one in the video will degreade to 80% capacity after 3000 cycles. So over 8 years of being used every day, the battery will loose 20% of its original capacity. Compared to the battery in my model 3, this one has an easy life.
Great video. My real world consists of solar panels and a Give Energy battery. At the end of the day this gives me free electricity, which runs my house and my car too. Combined with FIT (Feed in Tariff) I also receive payments, which I use to reduce my gas bill resulting in great savings. An air source heat pump would mean purchase cost of far more than I paid for a battery, replacing my rads, my combi boiler, my micro bore pipes, installing a water tank, plus cost electricity. This would mean an ROI for me which I would never see.
Thanks, sounds like a great set up
You also have to factor in the costs of insulation and improvements to existing pipework to make an Air Source Heat Pump a viable alternative source to a Gas Boiler - in many older properties you'd have to rip out all of the existing pipework because it's bore is too narrow - I am on a journey (it will take us about five years I reckon) to wean ourselves off Gas and move to an ALL electric based energy source, which will involve - at various stages of the process:
Ripping out many of the existing radiators - particularly those on the upper floor
Installing Battery Storage
Moving to the dual period electricity tariff referenced in this UA-cam video
Changing our ICE vehicle to an EV
Installing electric underfloor heating - particularly in rooms on the upper floor
Installing Solar Panels and linking them into the battery storage
Significantly improving the level of insulation in the house generally - cavity wall and loft insulation?
Replacing the smaller number of radiators we retain with more efficient modern alternatives
Replacing our gas boiler with an electric alternative
Our house was built in 1952 - I've looked at an Air Source Heat Pump and ruled it out as NOT feasible, due to the huge cost and disruption involved in making it work as a potential alternative to a Gas Boiler
Just get several small air con units like me. Cheap & you get cooling in Summer too.
My most recent video touched on this topic, check it out ua-cam.com/video/O_fs_Du1GzE/v-deo.html
We have a 2014 Nissan Leaf with a 24 kWh battery. It's done 75k miles and the usable capacity is now in the region of 75-80% or 18-19 kWh which gives us a maximum range of somewhere in the region of 75 miles on a charge. With the recent crash in second hand electric car prices and the likely number of these older, lower capacity EVs which are on the road, I'd really like to see some sensibly priced tech developed where the battery can be removed from the car and utilised as storage for the home.
A quick look at autotrader shows that a car like ours can be picked up for £3-4k. A home storage system with >10 kWh is likely over £10k at this point, and the market for an EV with such low range is going to disappear quickly. I have seen some DIY type systems cropping up on UA-cam but there's no way I'd be putting my house and family at risk by installing something like that.
If we can find ways to repurpose batteries from older EVs for energy storage for other purposes, then this will provide benefits for all parties concerned.
Good, interesting video.
I assume it's been mentioned elsewhere, but it's not exactly an apples to apples comparison. You already have a working boiler, but you don't have any energy storage. So you've already paid a fairly hefty sunk cost when you had the gas boiler installed or when you bought the house. You might not think about it in those terms, but you of course factor the fact that a house has a functioning boiler when you buy it and would lower the price you are willing to pay if it didn't.
In the end I opted to install solar rather than get a battery, as I get paid to export and save money whatever happens to the price of energy. Octopus is making a loss right now on their EV night rate and that's not sustainable forever. The day/night differential is not something you bank on being available for the whole life of the battery, which is why I think you should install solar first and a battery second, if you have the means to do so.
Also, if you have a hot water cylinder, you can divert excess solar PV energy into your tank using the immersion coil, reducing your gas demand. I plan to go gas free for my hot water demand, using the night rate to heat the water in winter and on cloudy days. And in summer mostly (hopefully) running the hot water off the excess solar.
I have come to the same conclusions. Will make a follow on video in the coming months.
Absolutely: sunk cost of existing gas installation; HP installation decorating cost if new rads/pipes; likely higher cost of annual HP servicing than gas boiler (not safety-crucial but said to be necessary for max efficiency); these are all factors overlooked by HP advocates.
We have a converted/extended 1950's bungalow of about 200sqm that currently is heated by an all (solid) fuel central heating cooker. Our annual solid fuel cost is around £750.00. Our electricity consumption is via E7 dual rate with about 43% consumed at night on the low tariff. Our electricity costs from Oct 2020 to July 2022 was ~£950, the annual rate is not consistent for this overall period. I can reasonably convert to heat pump but I will require a 21kW unit that is probably best on 3 phase, which fortunately is immediately available. The house plumbing and rads is already sized for lower flow temperatures as required with the CH cooker although I might simply fit split units off individual units around the house. I will keep and maybe upgrade the CH cooker as it has valuable advantages over simple heating/HW
Thank you for the input and sorry it took so long to reply.
Things become much more interesting to me when EVs and home chargers support vehicle to home. For our circumstances (vehicle only used on longer journeys on weekends so mostly idle during the week), that would help justify the cost of the car.
V2G would be a killer for me - having a xxkWh battery just sat there for when it's needed would save £££ on a larger fixed larger battery purely for the house...if you have PV then it's a no-brainer
A 2nd (used?) EV with V2L (vehicle-to-load) makes a lot of sense, would have more available KW/hrs than a home battery and it likely would be cheaper. Another big advantage is that it is portable--if you had a local & sustained power outage, you could simply move your EV (storage battery) to a 2nd location (temporarily) for charging.
@@michelem.6104 exactly that - a used 24kWh Leaf used to be around £5k in the UK (more around 6-7 now) but compare that with a home battery, you're looking at that figure for around 10kWh - it will get there but the notion of energy with a vessel to store it in needs to be separated from the 'thing' that is using it - much like the 'multi-tool' batteries for gardening/DIY etc - admittedly the EV needs to have a fixed battery but OEMs need to make that energy available for V2H or V2G and charger/inverters need to catch up to make it happen at a decent price point - it seems ridiculous to me that there is duplication of hardware all around!
V2G / Bidirectional charing will be a game changer but only for people with a garage or driveway ua-cam.com/video/Re3QkHhuG1c/v-deo.html
Air source and ground source are only viable in new builds with room for the storage tank etc, end of. With regards to battery storage, make sure you note maximum loads as the givenergy can only discharge 3.6kw meaning you will kick in mains for a top up if you put the kettle on and have a standing 400w running house (tv, wifi, fridge freezer etc). Powerwall and some others discharge at 5kw continuous and if used with solar are ac coupled meaning the solar can add to this (we personally can sometimes be feeding 9kw from our battery and solar continuously).
You are correct.
Can’t you use nighttime tariffs for the heat pump too? In the summer you can crank up the heat pump to get the house very cool at night, and turn it down (or even off) during the day? Similarly, in the winter can’t you crank up the heat at night, and turn down the heat during the day? If your house is well insulated, and you keep the windows closed during the day, and keep the blinds closed too, I suspect for many homes this would work just fine. I know people who use this technique who don’t even have time of use pricing, they do it in the summer because the heat pump is cheaper to operate when the temperature differential between outside and inside is smaller.
m.ua-cam.com/video/0f9GpMWdvWI/v-deo.html (by Technology Connections) discusses exactly this at some length, focusing on the aircon in summer because he's based where that matters more. There's a long intro about various forms of energy storage, so if you are mainly interested in his use of his house as a thermal store fast forward to 6:47.
He gives figures of what he was saving in summer 2021 when he made the video
@@trueriver1950 Yes, great video on Technology Connections' part. I'd forgotten about it, but with your reminder I now remember watching it. :)
off peak tariffs will be phased out very soon. I will be making a follow up video in a few weeks time. All these points will be included.
@@RealLifeArchitecture Off peak tariffs will be phased out? Interesting, I thought that was the direction things were going around the world. I look forward to the video to learn what jurisdictions, and why, are going a different direction.
Given your very high consumption of electricity (car) you really need to install PV asap to reduce this. Most people who install PV on their roof produce power when the sun shines and not necessarily when they need it but if you have a car to charge that becomes a lot easier to manage. Furthermore, if you had chosen a recent Hyundai or Kia you would be able to use the ~70kwh battery to perform the function of the Giv-Bat without breaking a sweat up to an instantaneous draw of 3.6kw.
True that newer EV’s can give power back. Bi directional charging could be a game changer.
Really interested in using vehicle to home charging but is it possible to set it up so it isn't tied to the grid? Otherwise the only times I see it being used in the UK is via the small scale vehicle to grid trials.
Battery storage makes sense when combined with solar. You forgot to calculate that you lose about 5% efficiency when you charge and discharge your battery (at minimum).
Thanks, I was not aware of the 5% issue
The heat pump if installation is done by a good experienced company you should get 4.5 kw per 1kw of electrical power in .
Also with the current gas situation and the fact it's carbon free and gas is only going to go up and installation costs will it's best to get one sooner than later 👍
Im not convinced, I think this technology is still developing and mass production will bring the purchase price down.
Off-peak electricity will become more popular with more battery installations, so given the law of supply and demand, there will be no savings (soon) by using a battery to cleverly "buy low and sell high".
As you mention, the availability of the night rate (off-peak) has already been discontinued in some places.
True
Great video, thanks.
I'm in a situation where I'm trying to move away from oil heating and stinky oil tank that comes with it (no gas where I live), so the main purpose would be for heating water and the house. I think this means air source would be the better option for me, as much as I would prefer solar + battery combo.
I see you're a Bulb customer too - do you know if they will honour the reduced night tariff once we're moved to Octopus?
I don't know, I am still waiting on confirmation but I suspect it will end up costing more once the move has been made.
Hi what size battery storage would you need, to have enough stored cheap night time energy to also power a heat pump during the day? maybe the trick is to have a good balance between both systems,
in other words does battery storage make a heat pump more viable financially?
Possibly but the battery would need to be about 6kWh bigger and that would cost ££££ more
Based on over 20 years as a Gas installer, over 70 heatpump installations (new build and retro) and living off grid for electricity for the past 3 years. There's not a cat in hells chance my Newbuild house will have a heatpump, if I'm "forced" to have one to tick a box, it will be "borrowed" box ticked and returned. Solar & batteries can realistically give you 100% of your domestic power for 8 or 9 months of the year, the rest you cover with mains or genny, my annual red diesel bill ( for 9kva genny) is way less than the standing charge for mains power.
You are probably correct regarding new build homes but the vast majority of homes in the UK are old and will be difficult / impossible to upgrade. The gas system will remain for the foreseeable future
Hi Neil, I came to the same conclusions as you and have installed solar with 17.4kw battery storage. I have two electric cars and will also now switch to the “go green” electric rates as we now have a smart meter installed. I am also looking at a heat battery for hot water generation as this can also be charged overnight on cheap energy or from the solar panels during the day.
The heat battery sounds interesting, who makes that?
@@RealLifeArchitecture Sunamp - a British company no less!
@@rocket3man thanks I will look into this
@@RealLifeArchitecture I think that they're Scottish as well!
One other major technology left off here, is one that the public isn't aware of too much, which is of course an MVHR
My plan of action is as follows :
Get solar panels + batteries first
Then an MVHR
Then oversize radiators
Then a heat pump
That’s a good plan but heat recovery only works in buildings with good air tightness. That usually means a new build. This technology isn’t suitable for the majority of older properties in the UK. They are draughty and the may not be space for the kit.
Solar plus batteries is a more usable tech, however.
@@RealLifeArchitecture I saw online that it's still good even at low levels of air tightness
Also fwiw, I got a low energy architect, and they advised pretty much the same. I'll be making my house more air tight, regardless . They did however advise against external wall insulation
I am also now looking potentially into "air to air" heat pumps ie: aircon but in reverse and just rip out the radiators
That battery sounds small. We started w 5kWh of battery, but it would not sustain the microwave and Induction hob simultaneously. We're now up to 20kWh of battery on a 5kW inverter (Growatt), which seems to be doing the trick.
Thanks for the info. I will be making a follow up video on this in the near future
Problem I have here in the Netherlands is that the ‘night time’ tariff = 0.32 euro while the normal tariff = 0.38 euro. So the gap isn’t large enough for this type of installation.
It’s become the same in the UK.
Off peak tariffs may be phased out soon
Very informative, the ASHP will have a 10yr lifespan and is not maintenance free, the batteries subject to chemistry should last longer and far less maintenance. Embodied carbon is a topic if being completely green is you goal and finally, continuity of supply, with battery storage you can technically with a bit more investment operate with the utility being off.
All good points but since I made the video it seems that low cost off peak electricity tariffs will be phased out.
Thanks, I have an old house, very old (1686), so ASHP would be almost impossible, 24 inch walls etc.
So I have gone for the usual insulation and now have Solar, home battery, and EV with V2L.
I am reluctant to go above my 7.5KWh home battery as the pay back is long, and totally reliant on cheap night rate, if we all get a home battery then the suppliers may no longer offer cheap night rates.
Even so I am now updating white goods to high efficiency and load shifting.
Night time tariffs appear to be on the way out regardless.
just for comps. Our 3.6kw pv and 13kwh growatt install was £11,875 in june 2022 in the south east of UK
That sounds like good value. What was the lead in time / delay between ordering and installation?
@@RealLifeArchitecture a few weeks. Think they're a bit longer now. (And a bit pricier)
Flat roof garage install, no scaffolding required.
Wow those bills are quite big ! One word of caution ... How long is cheap night time electricity going to last ? With people charging EV off peak , the demand for off peak electricity will rise & the discount go down.
I have been looking into this and it seems you are correct
Really interesting video - thanks for sharing your thoughts on this. I'm an EV owner too (BMW i3 33kWh) and consume around 2800 kWh of electricity per year to drive 12k miles. In addition we consume another 6800 kWh for other household loads.
Our heating is an externally mounted oil fired boiler which is around 14 years old now and is starting to need regular repairs so we were considering a heat pump, potentially ground sourced since we have a 3 acre paddock next to our house. The house is partly a 150+ year old cottage with solid stone walls, and partly an 2 story extension which was added in 2008 so we have a mixture of insulation standards which was a big concern for me if we were to install an ASHP or GSHP.
I'm currently refurbishing a 10m x 10m outbuilding next to the house and intend to fit solar panels on the roof but the lead times on installations are pretty long just now for obvious reasons. I did wonder if I should try to get a battery installation in the shorter term to allow me to switch to a tariff such as Octopus Go. We were with Octopus Go at 14.5p and 5p (00:30-04:30) per unit before the energy crisis but the rates are now 35p and 7.5p so the penalty for using power outside the "Go" window is much more severe. The result is that we are better off staying on the standard variable tariff which is 29.84p peak and 21.34p from 01:30 to 08:30hrs. If we did employ battery storage then we'd probably need 2 of the GivEnergy 9.5kWh batteries to deliver the 18kWh or so that we consume daily excluding the EV.
So I guess I need to do a few calculations to work out the return on investment of a battery system for my situation but it sounds like it might be feasible. Advice welcome. :)
Your situation isn’t unique, most people in the UK live in older properties, which have been altered over the years. I’ve also had several sources tell me cheaper off peak tariffs are on the way out. I am now thinking solar PV with some battery is the way to go.
@@RealLifeArchitecture yeah it's a good point - we shouldn't rely solely on a cheap tariff like Octopus Go because right now there is no way they are making a profit from 7.5p/kWh at any time of day! Even the Agile Octopus tariff is currently maxed out at 35p/kWh for the entire day whereas it used to go negative on occasion. I dread to think what the unit prices are going to be come the winter because even 29p/21p (peak/off-peak) is artificially low due to the current price cap. I can only assume we're headed into 40p+/kWh territory when the new price cap is decided...
I recently took part in an initiative with Octopus in conjunction with the government where they would tell you 24 hours in advance of a 2 hour window where they would actually PAY YOU to use energy. As an EV owner it was very easy for me to reschedule my charging to coincide with that window as well as running washing machine, dishwasher etc. So I ended up making £32 in total from I think five or six such 2 hour windows. I suspect that this might be more the sort of model we see in future where those who are flexible about time of use can benefit significantly by pulling power when supply is plentiful and vice versa.
In terms of energy saving, the biggest difference I have made in our home recently was by installing a full set of smart thermostatic valves throughout our house. We are using the Tado system and I'd say it has reduced our heating oil consumption by 40% by allowing us to heat different parts of the house to suit our actual usage. Yes you can do that with manual TRVs as well but nobody is going to go around the house several times a day adjusting them. Our biggest saving by far was avoiding heating our lounge, which is fully inside the oldest part of our house, during the day. But also we save money by reducing heating in various other rooms such as guest bedrooms. We can also boost heating to places like the en suite after we have had our morning showers to help clear the damp air away and dry towels on the radiators. It really has made a huge difference and my wife is happy to use the app too so it's not just for tech geeks like me! :)
Lastly, I recently installed an Emporia Smart Home Energy Monitor which uses up to 16 current clamp sensors to monitor individual circuits coming out from your consumer unit. This has been quite eye opening in finding where my electricity is going each day and has already led to changes such as switching off our dehumidifier except when drying clothes indoors as it was costing us over £150/year in electricity to run. Well worth a look.
Very similar setup to mine albeit we have a late 80's large bungalow. Currently running 8kw of solar for house, and 4kw solar for Tesla. Built a 9Kwh battery for car charger which gives about 70 miles a day roughly. The house has 17Kwh battery with another one on the way. Swapped out the Tuble Dryer for a heat pump one that just sips electricity. I was going to go on the cheap rate Octopus Go tariff but think I'll stay on the 30p/20p standard tariff as I really don't want a smart meter installed.
Heating I am ripping out the oil burner and all the radiators...emersion heater etc... Putting in Heat Pump to Air Conditioning for heating and cooling. Will be nice to have a radiator free house, positive airflow pressure from attic into house to stop damp. And a Sunamp phase change for water heating
I think the dial home newer ev chargers will be the way the government tax electric car use in future, pretty sure they passed a sneaky law during 'c o v i d' that allows entry to your property to take electric car meter readings without a warrant and without your permission. I did wonder how they were going to tax the EV's.
Hi what you are saying doesn't sound correct to me. You haven't included the cost of charging the storage battery. You have assumed its fully charged each day. Surely its not without cost to charge the battery? Also can it be charged within the 4hour cheaper electricity period?
The entire calculation is based on charging the battery during the cheap period...
You need both for resilience along with as much solar as you can squeeze in.
In the ideal world, yes but it’s not always affordable. I made the video from the viewpoint of having to choose between them in the basis of return on investment
Very good Video, Some points.
Heat pumps are sold on a 3 to 4 times heat output per KWH, and under perfect conditions this could be the case, A test (under controlled conditions) was done and this turned out to be 1.75, i can't find this info at the moment, i believe it was done by octopus.
The next problem, they need to run 24/7 due to the lower heat output, so if you haven't got excellent insulation it's going to be very expensive, and I like to sleep in a cool bedroom, and wake up in a warm one.
And the maintenance costs and servicing need to be considered.
Now the battery idea is excellent, as you have pointed out.
The 6k you mentioned is about right, but i expect 2k of that would be the inverter and fitting.
So i would strongly suggest spending 10k and doubling up on the battery, and if you haven't already thought of it fit a hybrid inverter so you can fit solar at a later date if you get the urge.
I have been running 10kwh of batteries now for about 6 months and my only problem is, I wish I had 20kwh.
The problem with all of this is predicting future energy costs, I see heat pumps in any environment as a big gamble, and can see electric at the very least 50ppkwh or more for the next 2 to 3 years, and gas at 15-20ppkwh, the wholesale price of gas at the moment is over 12ppkwh.
Anyway best of luck.
You make a lot of good points but I am seriously considering the solar option. Cheap off peak tariffs will soon be a thing of the past.
@@RealLifeArchitecture Looking at the wholesale prices, it's been a thing of the past for the last 12 months.
Just look at the logic, everyone will be charging their cars at night cheap rate or not, as will be using them in the day, so other than the 4 to 7pm peak the grid will just about be utilised 24/7.
The only way round it is solar, assuming you can get enough panels on your roof and some batteries to store it.
@@williamcox1176 very true, am crunching the numbers at the moment. Who know, if the channel takes off I may have the money to fund all this 🤣
There is no room outside my flat to install a heat pump.
You should re do this video with October's price cap prices. Electric is now going to be 49p something per kwh and gas nearly 15p kwh with standing charges of 55p E and 37p G. These are rounded up or rounded down figures. I hope you all fixed your energy.
Thanks, a follow up video is on the way
Curious If the recent price changes for gas have changed your calculations.
No, but since making the video it seems off peak tariffs are being eliminated by most suppliers.
In NZ with ASHPump air to water doing hydronic underfloor heating in a well insulated but cold climate .Night 10hr/day14hr tariff of 6p/20p daily charge 17p .It costs 11 times 6 = 66p/night to heat house .Wood burner needs to supplement space heating for about 4 hrs once a week over coldest 3 months. Well designed house (thermal mass and eaves) mean no summer cooling needed. I have EV also so 6p/kwh drives 3miles ie 2p/mile. Soon we will be able to use the EV car battery as a storage for house use saving the wall battery cost. Yearly usage is 8500kwh at 2.6 pounds a day.
Your running costs are way lowers in NZ than UK
If your car supported V2G or V2H you could use your car as an alternative to your battery or have a smaller lower cost fixed battery (assumes you WFH for the majority of your time).
Yes: in fact he says in another reply that both he and his wife WFH so using the car as a battery makes sense, so long as he factors in the times he needs to keep it fully charged for a planned trip; or if his business requires him to make long trips with zero notice
Thanks, my Model 3 doesn't (yet) support V2G.
Good analysis. But there is one area that you missed. The battery system is electronic/electrical. Yes, batteries aren't perfect, but they are good and rapidly improving. The heat pump is largely mechanical for the guts of it. My experience is that mechanical systems don't have the same reliability. Looking at my own home, it is the "good ideas" with mechanical systems that are the ones that fail. Would a heat pump get anywhere near 44 years of life? I think not. My view is to stick to "non - mechanical" systems where possible.
👍
Thing to consider is the lifetime of a heatpump is 20 years while gas boiler is 15+ years, also proves heatpumps are still worth it if swapping out a gas boiler anyway
I think ASHP need to drop in price substantially before they become sensible
That's a matter of opinion, because we don't really know the reliability of the heat pumps that are coming into today's markets. There have been big improvements in efficiencies, but only time can tell us those come with hidden obsolescence, not necessarily deliberate.
Yeah you can find heatpumps from 20 years ago that are still running. Their SCOP might be around 2 or maybe 3 at best. Today manufacturers are claiming 4. The tech has changed over the lifetime of that unit built at the turn of the century and we cannot assume all the changes will turn out to be for the better
I'm not saying that you are wrong. What I'm saying is don't be too sure about any opinion (including mine) of a tech that has doubled its efficiency over the lifetime of an appliance.
Thank you I was going to get a heat pump as I have a gas combi system and my house is of similar size to yours and I have an eclectic car which I do charge only on off-peak electricity a power wall is definitely the way to go plus I am thinking of installing solar panels on my garage roof to charge the car as well and whatever leftover charge can go to the battery now solar cells have come down in price dramatically so I am going to fit 5 full panels to my garage get a controller fit it but not connect it I will get a specialist to do that and check over the system as I am competent in wiring 240 and 12volt I used to rewire houses with my dad who was a certified electrician I used to help him out on big jobs I always go above code as you can never be too careful with current so he will connect to the easee robot car charger as it's over a 1000 pounds for that unit and I don't want to blow it or void its warranty. same with the battery when I can afford to get it installed in my garage which will feed the house during the day I am at home all day as I am disabled now but can still do some jobs it just takes me a lot longer than before between rests. lol but I do believe it will save me a lot of money and when I can afford it get a small wind generator on the house roof to power at night and during the day as well helping me to get off the grid and finally get a company in to install solar panels to the house roof with another power wall so two power walls and then I should be able to stick the fingers up to the power companies and tell them to shove it the robbing you know whats, LOL. no not really I am too kind but I will think it as they are robbing us blind to keep their shareholders sweet it was the worst thing the conservatives ever did was to privatize the utilities of our houses power and gas and water biggest mistake ever this was predicted by Enoch Powell and everybody laughed at him now whos laughing they all said he was scaremongering well here we are now I never liked the man but I respected his views and I could see what he was saying way back then and all that he said has come to past I really wished he had got it wrong boohoo.lol bye
Its not every day I find myself agreeing with Enoch Powell...
If anyone wishes to save money you have to go off grid and produce your own power, yes there will be a cost to purchase the equipment to do this but if it doesn't rely on an energy company to run you will genuinely save money. Example Solar Evacuated tubes to create hot water, with the circulation pump run by solar .Even this method you still rely on the the water company.
Good point
I think that the impressive thing is that electrical heating has now hit price parity with gas heating in day to day running costs. It's less about payback time and more about being a viable replacement for gas. I wouldn't rip out a serviceable gas boiler right now but I would probably replace a boiler at the end of it's lifespan - especially as the future of gas looks unstable but electricity will likely become cheaper as more renewables come online in the long term, it just seems like the safer bet if you have to pick between the two sources of energy for a new system.
I'm in the process of buying a house with my partner. it has no central heating atm, we assume it had storage heaters at some point however none are in the property now. We plan to install an air-to-air heat pump system before we move in. Heat pumps make sense for us as it'll effectively cost 1/3 less to heat our home vs resistive electric heating. Another benefit of having our heating supplied via electricity is that it will improve the payback time of a solar+battery system for us when we look to get one in the future.
Gas is still cheaper in the UK ua-cam.com/video/im9cSDPHjDk/v-deo.html for now
@@RealLifeArchitecture should it always be about cost?, do we not owe it to our children and grandchildren to stop burning carbon base fuels.
@@RealLifeArchitecture the OP is talking about using a heat pump, not resistive. Your own calculations in this video show the heat pump to be cheaper than gas. Why would you link to your old video saying resistive heat is more expensive than gas?
Philip,
renewables are why electricity is so expensive and it will not get cheaper if more come on line, the reverse will happen.
@@iareid8255 That's likely a short term thing and as renewable is getting better and cheaper all the time, it's likely going to work out cheaper than all the other alternatives.
There is also the option with renewables that you can install them on your own house and with that, I think longer term, going the electric route with heating is likely going to be the better option if you can generate enough energy at home.
Still, I tend to find the best solution is to reduce heat loss in the home whiles reducing heat getting into the home and overtime, replacing items around the house with more efficient ones, something we've been doing at my house for about 15-20 years and reduced our energy consumption from around 30 kilowatts per day to around 16, this is whiles having more computers and other tech gadgets around the house and I think it's likely less than 16 now because I last checked about 4 years ago and since then, I replaced my induction hob and dryer, both of which are a lot more efficient, especially the induction hob which the older one was something like 7 kilowatts whereas the new one is 3.6, so at a guess, I suspect I'm probably using around 14 kilowatts per day.
Without other advancements in tech, there isn't really much more I can do apart from heat pumps, solar, wind generating and battery storage tech, all of which are quite expensive.
In any case, what I found remarkable over the last 2 decades is how you can reduce your energy a lot without changing your quality of life, in fact I would say the quality of life is better because I'm using more goods even thought I'm using a lot less energy.
that has blown my mind definitely interesting food for thought
Glad you liked it. If you have any ideas for future videos, let me know
@@RealLifeArchitecture Many people ask me whether or not it's best to leave the immersion heater in the cylinder on all the time or turn on only as needed and I've never had an answer for them, only for them to experiment themselves. Would this be something you would cover?
You are using the most optimistic figure for airsource heatpump efficiency, you will only get 3.5Kw for every 1 Kw used by heatpump in the summer at 25deg C ambient or higher ( when you need the heating least ) - but in winter at >10 deg C you will get nearer 1.5Kw of heat for every 1Kw of power into the heatpump - this makes the battery even more attractive, and much less disruption to your house.
You are correct and this has been noted in the pinned comment. I will be making a follow up video in the near future
Thank you for posting this Neil. Compelling facts.
No problem
Would you consider the savings made by swopping the gas with heat pump and supply with battery it seems a viable option. Storage tank as buffer
which heat up with night tariff with heat pump also would work.
I’m going to look into this in a future video
Not a huge dent but if you also removed your gas supply, you'd be saving another 100/annually due to the standing charge removed.
So rough saving of 235 annually, still 25.5 years to get ROI
True
A really useful video. One important thing to consider is the range of available heating options. I completed a self build in Cornwall 15 years ago and installed an air-water heat pump with underfloor heating in a concrete slab downstairs. Because of the level of insulation we only installed towel rails in the 2 upstairs bathrooms and the house was never cold, although we did run a woodturner on colder evenings, leaving the lounge door open so heat would naturally convect upstairs. We ran the whole house on economy 10 which gives 10 hours of off peak, including off-peak times in the afternoon and evening. It probably worked out slightly more expensive to run than gas, but that wasn't an option in our village so we were comparing against solid fuel, oil or propane making it a simple decision. 15 years on and the ASHP unit expired, just as we were agreeing a sale on the house, and had to be replaced - bad timing.
Now I am looking at the whole thing again. We have bought a 1970's 2 bed semi in another part of the country - our son will be living there as we are working abroad for a while. I don't have any figures for current energy usage but, for me, doing nothing is not an option as the house currently has manually controlled storage heaters and an an old copper immersion tank with only an insulation jacket. The roof faces almost east-west so not ideal for solar and on a 2 bed house isn't huge anyway. Considering I have no wet heating system in the house at all, some form of solar system and/or air-air HP is looking like a promising option. Battery systems are fairly new to me but the figures seem to add up, particularly when combined with PV. Another option I have come across which may work for the house are smart a controlled water tank and storage heaters that automatically heat using PV output and cut down on electric usage over night. There is however the issue that most heating is required in the winter when PV output is generally lower.
I'd be interested to learn more about the output that could be expected when installing PV on a less than optimal roof, and would welcome any recommendations for this particular set of circumstances.
As it happens, my roof faces East/West. I will be looking into this in greater detail in the coming months.
Wow! That's a similar situation I'm contemplating with a prospective self build (east-west narrow strip of land); so glad the YT algorithms lead me here 👍🏿
@@RealLifeArchitecture If my 'land disposals' enquires prove fruitful and I get the nod for my self design and build (usual planning/local design guide constraints), I'd love to keep you in the progress loop 👍🏿 ps, thx for a brilliant, logical presentation - subscribed!
The quote you received for the air source heat pump seems very low to be honest.
Did that also include the installation of the hot water tank and all the plumbing/electric for that?
Thinking about the battery idea, it might be a good idea to charge the battery at night and use it to power stuff during the day, that alone would save you/people a fair amount of money, as you'd be paying 1/3rd the price.
I have the economy 7 meter/rate in my home and it never dawned on me to run things at night, primarily because I keep forgetting modern day dryers and other appliances come with a delay timer.
I often wonder how much I could've been saving if I had done that with my dryer in the garage for all these years!
The quote didn't include for anything other than installing the ASHP. It also seems that nighttime / off-peak tariffs will be phased out.
@@RealLifeArchitecture I'd heard the same about the night rate being phased out. More good news eh? heh
We have an ASHP and home battery installed. I agree with your maths - but the ASHP gets much more attractive when a home battery is also installed. My FoxEss 18.2kWh battery cost £7,500 (with a usable 16.4kWh) which covers 100% of my home demand in the summer - we'll see about the winter. I do think ASHP economics are muddled by the current (relatively cheap) price of gas. Even at a 4:1 COP, and ASHP is effectively delivering the same heat output as gas for a similar cost (because 1kW of electricity is 4X the cost of 1kW of gas) - so no opportunity to offset the high initial cost - but that changes with a big battery + ASHP.
Thanks for sharing, I will be making a follow up video in a few months
Looking into battery storage myself. I would need 14kw average. I've been quoted 10k for install. As an electrician I have friends who install so will see if I can get better price. Some problems are battery invert or can not power high demand items, plus ev demand could soon use up night time economy tariff. So apart from my solar putting some surplus into battery it's a big gamble.
Agreed, am hearing that nighttime traffics are being reconsidered due to increased demand
If the night time tariff changes, it will likely be to an agile tariff with an even larger differential. Electricity companies really, really don't want EV owners charging at peak times!