Very interesting. I too have been through this and have similar objectives. I mainly considered GivEnergy and Huawei. I've gone with a Huawei system 15kWh battery with 6kWh hybrid inverter from 8kWh PV powering a heat pump and also on Octopus Go with a Zappi and Eddie. The battery technology is the same Lithium iron phosphate (LiFePO4) but the Huawei is a high voltage battery at around 385V instead of GivEnergy 50V. The advantage with the Huawei inverter is that it can power the house with AC at 6kW max from solar whilst the battery simultaneously charges at 5kW (if there was enough solar!) and the battery can provide 5kW output. Whereas GivEnergy's hybrid shares it's 5kW maximum rating also it can only charge or discharge the battery at 2.5kW max. So if the house load was 4kW you'd only get 1kW into the battery. If your house load was 1kW you'd only get 2.5kW into the battery - so your solar goes to waste. I also found it was slow to ramp up, so every time you switch something on the first 16 seconds or so of extra demand is fed from the grid before the solar or battery ramps up to 100% of demand. All these spikes of grid energy add up during the day. That was when I enquired early in the year and they may have improved the spec as they recognised it was a disadvantage. The Huawei is much faster to respond so doesn't clock up all those initial load switches. The Huawei can provide grid tied mode which goes into standby when the grid fails, automatic backup (with an additional backup box) mode which is meant to keep critical circuits going, and a full off grid working mode. Theoretically the full off grid mode could power your house up to 5kW but as with any system primarily working grid tied it has to shut down or isolate when the grid fails otherwise it will attempt powering the grid which could be a safety issue down the line at a wire break that's expected to be dead. You are right to not be concerned about optimisers. As I was reminded only the other day, there are reverse biased connected diodes in solar panels to ensure that if a column of PV cells goes high impedance due to, say a leaf falling on a cell, the cell is protected from becoming reverse biased by the combined voltage of all the other panels in the string which could add to a high voltage. The diode becomes forward biased instead which limits the reversal and the current bypasses the affected column so the affected cell is only reverse biased by the other fewer cells in the column. So PV panels automatically optimise to an extent anyway. You may lose a couple of columns from a leaf but not the whole panel. If the shadow crosses all columns the panel output will be lost but the other diodes in that panel bypas the current so the whole string only losses the output of one panel and the impedance it's kept low allowing the inverter to maintain optimised power transfer. Where individual optimisers help is where there is partial shading of one or more panels, perhaps through a tree canopy or dirt film, not enough to switch off the cells completely but raising the impedance of the working panels. The cells don't become reverse biased and the diodes don't bypass the current but the raised impedance can cause the inverter to limit the power draw from the whole string as it starts to see the voltage collapse under load. Optimisers maintain some useful output from the affected panels but don't don't raise the impedance of that section and the whole series connected string, which would loose more power. Power is usually optimised in the inverter by taking increasing current from the string until the voltage voltage starts to fall so it finds the sweet spot for voltage x current = power maximum (MPPT maximum power point tracking). Optimisers can cost as much as the panels though. Anyway, It's just seen you have another video about a second battery and spreadsheet calculations - something else I've been through sizing mine.
That's very interesting, I hadn't looked into the Huawei system in too much detail before, so you've given me something to think about. Thanks for explaining your system. Good to know that it can do power-cut back-up if needed too. I saw a good video this week by Gary Does Solar on optimisers explaining it in the same way as you and that makes a lot of sense. I'm pretty confident I don't need them now.
@@TimAndKatsGreenWalk Yes, it was Gary's video that reminded me about the protection diodes. He explains very well how it effectively optimises. I remember them being explained as reverse bias protection in a lecture many years ago but I'd forgotten.
SolarEdge Energy Bank does allow backup, you just need the right inverter and a backup module. Other advantage that makes a big difference is that any generation that would normally be clipped by the inverter is used to charge the battery so if your 6kW array is maxing out and you have a 5kW inverter the extra kW goes into the battery instead of being clipped and effectively wasted
Yes, I'd seen that about the SolarEdge system, quite a neat feature. I've calculated that our E/W array will max out at about 5.3 kW so possibly not super relevant for us, but neat nonetheless.
It only allows backup in it's three phase inverter. For single phase you need to wait till the reales next year of the 'Home HUB' with a backup interface.
I have your option 3 being installed hopefully next month. I believe the hybrid inverters are also more efficient than AC systems as there isn't as many DC to AC conversions involved. The other consideration for me was that the Givenergy system can be completely controlled locally without internet through the modbus interface that in my case will be going to Home Assistant. I believe this is important not only for system longevity but for control during a blackout when the internet might also go down. Time will tell if I've chosen wisely.
@@jerseyman99 I am having a Solar Edge system fitted and chose that because I use HomeAssistant extensively and I understood the Solar Edge system could be completely controlled off-line via the Modbus. but Tim's Conversation with John I saw yesterday said not. Can you point me to any good recourses please. I literally paid the deposit yesterday!
I had similar requirements for myself and went with the following i) Solar is AC coupled using the cheapest Solis inverters ii) Battery is AC coupled with Victron Multiplus . This configuration keeps me lock in free from any brand ecosystem. Further Victron multiplus is fully open / programmable system and I am integrating it part by part to my homeassistant setup. Victron will also provide support for power outages if wired that way. Build quality of victron is like a tank ! and that's what I wanted for such a busy device in this mix. For battery , personally I built it myself ( 2 X 12kwh LFP) but commercial options such as Pylontech are economical enough.
This is my ideal setup, but it's a bit more money so I'm saving up! I want off-grid for a few circuits for sure. I like the idea of a more modular system, plus when my cheap Sofar inverter dies one day there's always the option of bringing the DC from the solar into the MultiPlus-II via MPPTs to allow a hybrid-like setup and total control over each element.
Hybrid inverter without opttimister will be significantly less efficient. Though you might have little shading from trees, you will have significant shading early morning / late evening from the roof itself. Half the panels will generate very little, which without optimisation will drag the whole system down. SolarEdge also have a very powerful app, are firesafe, and their new home-hub inverter coming out within the next month will give great data. I'm planning to install int he spring.
@@TimAndKatsGreenWalk I stand corrected. Had not considered that. Also worth bearing in mind ability of system to be grouped together to work as a Virtual Power Plant. I don't know whether Octopus do this yet, but expect they will soon if not already. SolarEdge have had success in USA in grouping many of their home storage systems to gain revenue for homeowner and claim superior value in their speed of response. Believe several trials have been done in UK but not yet sure whether this is commercially available.
Givenergy Hybrid Inverter still limits you to a max charge (when charging solely from the Grid) of 3.6 KW. And max discharge of 3.6KW from your battery to your house. So even with two 9.5KW GivEnergy batteries you are still limited to 3.6kw limit when charging solely from grid. The Hybrid Inverter 5KW figure is when you combine that with solar generation. Battery is always limited to 3.6KW discharge and charge when using the 5KW Hybrid Inverter
Yes, I was alerted to this fact by another commenter yesterday. That might well change my plans, I'm going to do some more calculations and follow this up with another video soon, hopefully.
The 3.6kW charge / discharge is only if you have a Gen 2 hybrid inverter, it is limited to 2.6kW on the Gen 1 version as I found out when I boiled the kettle to celebrate my installation and found I was importing power!
@@TimAndKatsGreenWalk so true, it still grates every time as I was expecting to be able to draw 5kW. You might want to have a look at the reviews of the GivEnergy battery before committing to that route
Interesting to listen to your thought process Tim. I have just ordered a GivEnergy 3.6kW Hybrid Inverter, 9.6kW GivEnergy battery, Zappi, Eddi & 10 x 415watt solar panels. Like you I have no shading issues & all my panels are on one side of our roof facing 122 degrees SE. I could put a few more panels on the front of my roof to catch the late afternoon sun but I decided to keep the front of the house free of any solar accoutrements. Unlike you I have no plans to go down the Heat Pump route for home heating because our microbore heating pipework is far too small (10mm) & the cost & upheaval to rip it all out & replace it is prohibitive. I do have a small 4kW Air to Air Heat Pump in our conservatory which does a fine job of making it an all year round living space. So, on that basis I'm hoping that a combination of night rate electric & daytime solar should keep the battery & hot water topped up for most of what we use during the day & some free vehicle charging when needed - when we get an EV that is. As a retired couple we are at home most days which means we probably use more energy during the day than others who may be at work. That said there's only two of us now & we have started scheduling washing machine & Dishwasher etc to run over night instead of during the day. That may change when the solar system arrives. If I find we are using more energy than our battery & solar can deliver I guess an extra battery for more storage would be an option. However, as you pointed out, the max charge rate of our planned 3.6kW Hybrid Inverter would not be enough to charge anything much more than the planned 9.6kW battery during the 4hr night rate window. Do I need to go up to a 5.6kW Hybrid Inverter? I am also deliberating on where to put the Inverter & battery, in the garage or in the loft. My garage is small & is already rammed with stuff so a major clear out would be required to make some space. However, I've heard that a loft location for batteries & inverters is not the best for component reliability due to the high / low summer / winter temperature cycles. We also need a new consumer unit & our DNO needs to unloop our incoming mains electric supply from my neighbour before we can use the Zappi. I also need a new hot water cylinder because my 38 year old cylinder & immersion heater are well past their sell by date! I'm also in the process of installing a Tado smart system for our boiler, HW & radiators. This going green lark is starting to get a bit complicated & rather expensive.
Yes, indeed, it's quite a complicated and costly business for sure! As it happens we've gone for an air-to-air heat pump system rather than air-to-water because of similar issues with pipes etc. This way was far less intrusive and it'll also enable us to get rid of our radiators, which will free up a fair amount of wall space (and we'll get cooling in the summer as a bonus). I'm planning on doing a video about all that at some point soon. I don't think you'd get a faster charge rate from the 5 kW inverter, the charge and discharge rates are the same according to the data sheet (2.6 kW for both gen 1 hybrid inverters, 3.6 kW for both gen 2 hybrid inverters), so the 3.6 kW one is probably fine for you. Thankfully we have enough space in our garage for the equipment but I have a friend who has their battery in the loft and hasn't had any trouble with it so far, but I don't know what the long term issues might be. We're just waiting for it to all become available now, which seems to be taking forever! Good luck with your system and all your other plans!
@@TimAndKatsGreenWalk I have now decided that the garage is the place for the solar gear so I need to start re-organizing to make some space. I feel a visit to the local dump might be in order! I look forward to the video on your air to air HP system(s). I spent 45 years in the Air Con / refrigeration industry as a product design engineer / manager & in sales so I know all about the pros & cons of A2A & A2W heat pumps & many other systems besides. Heat pumps have been around forever & I remember selling selling large single packaged rooftop mounted ducted systems to many high street chain stores as far back as the early 1970's. A2W heat pumps (& to a lesser extent Water to Water / Ground loop) heat pumps are fine for new build homes but to retrofit them to older houses is far more difficult as well being more expensive. That said Air 2 Air heat pump split systems with ducted or hi / low wall type indoor units that cool as well as heat are becoming very popular for home workers who want to have the same facilities at home as they might enjoy in an office building or indeed the car that they drive. It's ironic that in the 17+ years that I was based from home rather than an office, I never had AC in my home work place - & still don't. The high wall split I have in my conservatory was a retirement present from the last company I worked for. LOL. Keep producing & sharing your videos because it's so important to have a balanced range of views & information about all subjects on YT for everyone to access & learn from.
@@colingoode3702 ha! That's very interesting. Well, I can say that so far we're very pleased with the A2A system, it's been very effective at keeping the house at a nice steady temperature with very little power usage, so exactly what we were after. I'm also very much looking forward to next summer when we get another heat wave and I can run the air conditioning for free using our solar panels (assuming they actually get installed by then)! I work from home so could have definitely done with the ability to knock a couple of degrees off the office temperature earlier this year. Thanks for your support and there will be plenty more videos coming in the future. There's still a lot we'd like to talk about and it seems a fair number of folks are interested to hear about it too, which is very nice to know.
Whilst the efficiencies you quoted for an air source heat pump are well known the actual energy use is affected by the heat losses in the house and the method you are using to transfer the heat eg. radiators, underfloor etc. We have a 4 bedroom house with underfloor heating upstairs and downstairs (EPC Rating A) and have used a heat pump for the last 12 years. In winter the worst case use is between 40Kw and 55Kw hours per day. Having said that we have replaced the old Worcester Bosch unit with an 11Kw Daikin this year so hopefully, that will be more efficient.
Yes, that's true, my numbers are an assumption based on having used ~60 kWh per day last winter using the gas boiler, and converting to a heat pump with an assumed efficiency of ~400% (which is the quoted efficiency of the system we plan on getting). What we actually end up using once we switch to that heat pump system will be the subject of a future video!
About optimizers: I had the same thought for our house, hardly any obstacles so why not make a 'bare' string and save on the optimizers (~70 euros per panel!). However, we decided to install them anyway based on advice from our installer, because these optimizers will *always* help when clouds come in play... after 3+ months now we can see that the amount of days with unobstructed full sunshine is very small, most of the time there is some (scattered) cloud cover.
I'd have thought cloud cover would affect both optimised and un-optimised arrays to a similar degree? The optimisers help when part of the array is shaded rather than the whole array, I thought. I guess there'd be brief window of time when clouds are passing over part of the array but most of the time they'd either cover the full array or none, given the typical size of a cloud. What I wish I could do is have two identical arrays for a year and test out the difference, but that's not really possible unfortunately!
@@TimAndKatsGreenWalk Yeah, no AB tests here unfortunately. One thing I forgot to mention is the way that these optimizers work together with the inverter: each panel reports its instantaneous wattage, and the inverter adds this together for the total amperage. Each optimizer can now calculate its share of the voltage (total voltage is always 400V) to reach this optimal current value. The total system now has a 'constant' voltage of 400V but fluctuating current, this makes it easier for the inverter to be efficient. With such a setup it doesn't matter much if angle of incidence, cloud cover or other obstructions limit individual panels. My layout has panels facing east, south and west - all in the same string!
@@diatonicdelirium1743 ah, yes, if they're all on the same string but facing different directions that'd definitely require optimisers. We'll have separate strings for East and West so not so important, I think.
I have recently had installed a 7.7Kw system almost identical to your option 1. However, I use excess solar to charge the batteries during the day up to about 80% at roughly mid day, then I "pause" the Givenergy battery so the excess solar charges my car. Once there is no excess solar, I restart the battery to supply our home. The solar panels have been in since May, but the battery system was only installed last week. During this last week, we have imported ZERO Kwh, so from that point of view, the system is doing what we expected so far.
OK Tim, this is my system for comparison. 6.4kW solar, evenly split facing east and west, with optimisers for each panel. I have a Tesla 13.5kWh battery, which I've set to only 10% minimum for power outage backup. I have a Solar Energy inverter, 6kW output. Heating is via Ecodan 8.5kW ASHP with underfloor heating to ground floor, radiators in bedrooms. Live in a 4 bed house built 2021, ~2k sq ft. First, forget the claimed efficiencies for ASHP. In winter, when temperature is around 0° during the day and the atmosphere is very damp (say thin fog), the ASHP runs continuously and freezes. Before I installed battery and solar this year, last winter my worst day I had 84kWh usage, this did not include car charging, and probably averaged ~60kWh when daytime temperature
Wow, thanks for all the information, that's very helpful. I have heard that about the Powerwall, that it's more difficult to make it do what you want, so that's something I'm bearing in mind with these other options. I'll be making sure that my installer gives me as much control over the system as possible. Also interesting to hear about your heat pump. We're going to be getting air-to-air, for various reasons that I won't go into here (saving that for a future video), so I'll make sure to ask our installer about freezing. I'm also in the process of building a little tool to help better calculate how variation from day to day in the required usage will impact the costs/savings, so it will account for days of very high usage. It's going to be interesting to see how that turns out (again, that'll appear in a future video). I'm committed to ditching gas and I believe heat pumps are still the most efficient way to do that, but part of the reason that I started this channel is to show a real world example of how this stuff works in practice so if I make a huge mistake at least others can learn from it! I guess time will tell.
I have option 2 SolarEdge Energy Bank with 3.68KW SE inverter and about 6KW of PV. Only had one issue so far, battery lost communication with the inverter for a few hours one day. We use about 9KWh a day and the Energy Bank should cover our usage 95% of the time. In the future I may add the back up module. I am currently waiting on Octopus to switch us over to the Go Faster tariff. I will add that so far the SolarEdge support has been excellent, they usually respond within 24 hours. The SE monitoring portal and app are also so very good, for me at least. At the moment you cannot set the battery to charge from the grid overnight via the Home Owner SE portal, you have to ask your installer to set it up. There is an update due later this year to allow home owners to do it via the portal and app.
Very interested in your excellent home storage presentation - Thanks. Just installed yesterday a Solarfast system with 8 Hanchu ESS LV batteries at 3.2 Kwh. (Total 25.6 Kwh) coupled with a Luxpower TEK Inverter. This is now linked to our existing 16 solar panels installed approx 11 years ago. We are hopefully downloading overnight at off peak rates at 3.5Kwh per hour (7 hours) with a maximum of 24.5 Kwh to cover daytime use including an electric Aga. We are using Octopus Energy. So far in 24 hours the system is doing what we expected without the benefit of much Solar input.
Wow, that's fantastic! I've ultimately decided to go for a 9.5 + 5.2 kWh battery so somewhat smaller than your monster system, I'm very jealous. I'm glad it's working out how you expected.
I've made a three part review on the SolarEdge Energy Bank. You can find them on my UA-cam channel. My opinion: Get a Pylontech AC coupled battery with a Solis/Solax inverter. Both SolarEdge and GivEnergy only allow configuration options to be accessed by the Installer. You have no access as a homeowner. In the case of GivEnergy, your warranty is also conditional of all work being done by a GivEnergy approved installer. Now at the moment, SolarEdge only allow installers access to Charge/Discharge battery profiling. That will change soon, but it is a demonstration of how little thought that they have put into how system owners want to use their batteries. Another problem with SolarEdge - your original installer has exclusive access privileges to carry out any further modifications to your system. So if you want to use another installer to add more solar panels, only the original installer can assign rights to your new installer. The new installer cannot adopt your inverter into their SolarEdge portfolio otherwise. That's a really poor philosophy. System owners, not installers should be the kings and queens of their system. Finally, there's no off grid backup option with the Energy Bank in the European single phase market. That's not a deal breaker, but if you're rural, or gas rationing starts to become a problem, it could be. As for roundtrip efficiency: They claim 94%. However when I aggregate charge/discharge throughput data, after a week I'm measuring 76% round trip. I'll be reporting on that in my next video, but I'll want to gather more data.
I agree, system owners should have better control over everything. Hopefully things will move more in that direction as the industry matures. As it happens I've already watched all three of your SolarEdge Energy Bank videos with great interest and am looking forward to any future videos about your system. I asked a question on your first video about the grid back-up functionality, and your answer was very helpful and actually informed part of this video (along with some independent research, of course). I'm now leaning towards only getting one battery in the first instance, whichever type that happens to be, and then gather data over the winter to see how it performs in reality before making any further decisions. I'm also in the process of building a toy model to help simulate the winter usage to see how much benefit we'd get from different configurations, and to give a better estimate of the costs and savings. Hopefully that will be covered in a future video within the next few weeks. Regarding Pylontech batteries, in principle that would be great but they have an annoying large footprint which I don't really have sufficient room for, so I'd prefer one of the more vertical style batteries, like SolarEdge or GivEnergy. I'll certainly be asking my installer to give me as much access as possible to whatever system we end up getting.
Thanks - very early in the implementation process but support to date has been excellent. Fortunately asked questions concerning limits on the download process. Your podcast would also have helped!! Ended up selecting the maximum battery storage for the inverter. May well have over specified!! At the moment 55% capacity available at 1500. The combination is also working with the myenergi for our Hybrid.
Been through the same thought process and currently installing the GivEnergy 5kW hybrid inverter with 3 off 5 kWh GivEnergy batteries. This is for 14 panels on an unshaded South facing roof. Factors were cost, total capacity, peak current (I have some very power-hungry machines), and also the 2kW supply in a mains outage.
@@munirshafi2647 The GivEnergy hybrid inverter provides a couple of socket outlets which are installed with the inverter and do work out of the box. I just have mine with an extension cable leading to critical items - WifFi, Boiler, CH controls etc. At considerably more expense you can get the installer to wire the supply into the critical circuits in the consumer unit. I think this is only possible if you design your whole electrical system with this in mind, as critical items will typically share a ring-main with non-critical items so it's impossible to manage the load down to 2kW.
@@munirshafi2647 Sorry, should have added, if wired into the consumer unit something would be required to isolate from the incoming mains to avoid back-feed. This is not required if you just use the sockets provided as the inverter provides this function.
Check out the MyEnergi battery announcement this week, The Libbi. Its capable of multiple battery storage stacking and back up during a power cut on a single circuit (so plugs or lights etc). I think the batteries max is 20kwh.
I wouldn't be hung up by the SolarEdge optimisers. Sure, monitoring is nice to have but if they go wrong then it's expensive to fix, unless you get them installed in the loft or don't require scaffolding to get to the roof. Plus people have made a few good points on UA-cam that they actually do very little to improve efficiency, as you've alluded to. Twin GivEnergy inverters seems to be your answer, but at present it's buggy but GE are apparently working on a fix. Some people already have this setup and it doubles the charge / discharge rate so would solve your problem. I'm going for 1 X 9.5 battery now to see how get on with the possibility of adding another battery /.inverter at a later date. Hoping the price of batteries drop as well so that might negate the 0% VAT loss. Plus with a bit of luck GE might bring out a Gen2 AC inverter next year with better charge rates.
I have 14x400w Sunpower panels with SolarEdge optimisers installed on my SE facing roof on Sep 2021. Coupled with an Eddi, Zappi, 5kW SolarEdge inverter and 8.2 AC coupled GivEnergy battery. I’m now waiting on my installer to add an additional 9.5kwh battery with a second inverter so that like you I can charge both batteries fully overnight. I had my one year anniversary last month and generated 5.6MWh and used 4.266MWh of that.
@@garyday615 very nice. I think I'm going to ask my installer about the option to use a second inverter at a later time as that does sound promising. I'll be interested to hear how you get on with that configuration.
Re SE optimisers. For our 4kwp system installed in 2015, we had an MCS forecast of 3400kwh/year and the system has generated between 3500-3700kwh/year since install. Thats with 2 out of 16 panels being shaded by a chimney for half the day that wasnt included in the MCS forecast. When you consider all the shading you could encounter, I wouldnt install a system without optimisers/micro inverters. Shading includes a patch of saharan dust, a patch of algae, a dollop of bird s**t, birds perching, fixed objects, neighbours growing trees, passing clouds.
Sorry a bit late to the party here. A few very important things to note: The size of the inverter can impact how much electricity you can draw at any one time. These numbers ARE IMPORTANT. Giv-AC 3.0 - Max DC Power - N/A, Maximum Charge/Discharge 3kw Gen 1 Hybrid Giv-HY 3.6 - Max DC Power - 4.5kw, Max Battery Output 2.6kw, Max Solar + Battery 3.6kw Giv-HY 5.0 - Max DC Power - 6.5kw, Max Battery Output 2.6kw, Max Solar + Battery 5kw Gen 2 Hybrid Giv-HY 3.6 - Max DC Power - 4.7kw, Max Battery Output 3.6kw, Max Solar + Battery 3.6kw Giv-HY 5.0 - Max DC Power - 6.5kw, Max Battery Output 5.0kw, Max Solar + Battery 5kw Option 1, your correct that the AC is limited to 3kw draw in either direction. Option 2 I suspect is MUCH more expensive than 1. Optimisers are a waste of money, adding a LOT of cost and added complexity of install and maintenance. Please watch these two videos for why. ua-cam.com/video/6Ucb-f8YPuo/v-deo.html ua-cam.com/video/E9NVLB_OYSU/v-deo.html Option 3. For powercut protection you need to specifically have an "islanding" mode installation. This essentially would give you a few sockets that allow you to run essential devices. It DOES NOT run your house and would be limited to about 3kw (ie 13a fused plug) per socket. The only device, currenntly, that does this is the Tesla Powerwall, although I am sure there are more products coming from other suppliers (pretty certain that these are available in different countries already Australia and South Africa come to mind). For an easy answer I would probably go with an AC GIvEnergy & Battery system combined with a DC Coupled system & Battery
Actually, the Gen 2 hybrid 5 kW inverter specifies 3.6 kW max charge/discharge rate for connected batteries not 5 kW, according to the data sheet, so it's the same as the 3.6 kW hybrid. I added a note to that effect in the description after I found out but I don't think many people spot that! The 5 kW output is reached by combining solar and battery though. I'm also aware of the need for extra electrical work to allow for the power-cut back-up, and that it's not the whole house that's covered, but thanks for making sure. Even the powerwall will be limited to 5 kW in islanding mode though, so you'd still have to be careful not to exceed that in a power-cut. Several other systems also have 5 kW power-cut back-up ratings but usually you'd set them up with a few circuits backed-up rather than the whole house to reduce the risk of exceeding the limit. I've decided to go with option 3 since I made this video, with back-up on some critical circuits, since I agree that for our situation optimisers aren't necessary.
We have a 5.4kWp solar PV array, Tesla Powerwall 2, Myenergi Eddi & Zappi and ASHP. Our ASHP and EV were later additions. Consequently, the solar PV and battery are now undersized, even using Octopus Go overnight electricity to supplement the solar. Our DNO is blocking our application for additional solar PV so we are likely to purchase another Powerwall to cover our winter consumption.
Thanks for the video Tim, I am glad I found your channel. I too have an E/W facing roof, and for that reason not going for solar, but only a battery solution. I too want to cover both electricity and heating at some point, which is why I am looking at a modular battery solution for now. Using the smart meter data for the past year, I can see we use on average 13kWh per day for electricity throughout the the year. I am also on Octopus Go, currently charge the EV during the 4 hours, and want to also charge batteries. The solution I have been looking at consists of 5 x US3000 Pylontech 3.5kWh batteries (48v) and a Victron Inverter 48/5000 (5000va) 48 volts with a Victron Gx device for the smart connectivity, however I am being told by various shops that this type of setup is for off-the-grid and will be hard to get installed, as they are trying to push GivEnergy products. From what I have read and watched on GivEnergy solutions, a lot more mixed reviews regarding the software side of things, which is my concern. An alternative solution with less hassle is Powerwall 2 with the gateway. Slightly more expensive, although I hear there is a big delay in getting PW installed. I've subscribed as I am very keen to see what you do next.
Yeah, I think there is still a lot of improvement to be made by a lot of battery manufacturers on the software side, which I can only hope will improve over time. I've got a friend who has a GivEnergy system and they're pretty happy with it so far. I considered a Powerwall 2 early on but decided against it in the end as I'd prefer to have a bit more control over how it operates. I hear they tend to do what they want rather than what you want, but perhaps there are ways around that. I'd love to be fully off-grid but that's not particularly practical for us right now. Maybe one day. I'd consider adding solar panels even though you have an E/W facing roof. That arrangement actually has quite a lot of benefits in terms of providing power over a wider span of time through the day, while only losing about 30% of the peak power, and maybe 25% of the total energy generation compared to a South facing roof. I'm actually quite glad we have an E/W roof now, having learnt more about the benefits. Good luck with your system, I'm sure you'll find a good solution eventually, and I'll be sure to let everyone know how I get on in future videos, regardless of they system we end up with.
I do have an E/W facing roof with roughly 3.7kWh of Solar PV on each side. This is actually a really good way of maximising solar output to power the home for more of the day. I have had my panels for West facing panels for around 11 years and 3 years ago, I added the East roof solar panels and a Tesla Powerwall 2, Eddi and Zappi. (eddi replaced an older water heater!) In the summer within half on hour of sunrise the panels are giving 1 kWh of energy and same at half hour before before sunset. It tends to give around 3.5kWh with a blip to near 5 just after midday as the sun is on both sides of the roof. For info, in 2021 I recorded 5747.5kWh of solar production. Using the Powerwall 2, I managed an 89% Night rate use, so it was very cost effective. I have since added an ASHP and this will be my first winter with it.
@@DahouiM Thanks and glad the information is helpful. We have found that during the winter the ASHP has kept us nice and warm, no problems at all when the temperature went into the negative numbers. Following researching as much as I could, I run the ASHP 24 hours per day, well the temp is set all day and it comes on as needed! We have set the home at 18c and it drops by just 2c overnight. Maintaining a core temperature for the home seems to be the key factor due to the lower flow temperature. Running the heating at 19c was too warm for me and it was jumper on/off all the time, so dropping to 18c was perfect with an extra layer! To confirm, our cavity wall has little to no insulation at the moment so my 1st year will have used more and we have a 5 bed detatched house. Our energy use for Domestic hot Water and heating has been around 3600kWh for the 12 months. The cavity insulation is being sorted for us next week and I am hoping to see maybe a 20-30% reduction in our use, when this is completed.
You can use tigo optimisers if you really need them due to shading with the GivEnergy Hybrid system. You can optionally install a tigo monitoring module into the string for viewing performance over the internet. I thought there is a GivEnergy portal for this already though? You’d need to get the GivEnergy EV charger for you to balance/manage supply between your EV and DC batteries. The Zappi can’t monitor DC. Heat pumps, look at daikin, specifically the solar pv/smart grid functionality. They can be triggered by your GivEnergy system when there is excess to heat the home or hot water. You’d need to get the GivEnergy smart plug and set the limit statically on the Daikin HP, say 1.5kW. Pretty much all Atherma 3 HP’s now have the solar PV/smart grid functionality. You can optionally install a smart meter with the Daikin HP to dynamically modulate it’s output to match PV generation, but I’ve found it jumps out of this window when heating hot water, a static limit is more deterministic and simpler to install/setup. I’m on intelligent octopus and heat the hot water tank at night with the HP. And I boost the house temp a couple of degrees.
The more useful aspect of optimisers in general, SolarEdge or Tigo, is that they can optimise multiple aspects on the same string. So if you wanted to do the south facing roof, along with your existing design you could. It may well be more optimal to have two rows of panels on all southern aspects, than three solely fitted to your south east/west roofs.
You are going to need two of either gen1 or gen2 Givenergy inverters, one for each of your batteries to meet off peak charging requirements. This could be set up with East on one set, West on the other. The only real difference of gen1 to gen2 would be the combined charge/discharge rate of 5.2kW Vs 7.2kW ( and ethernet/WiFi built in gen2). If you're wanting optimisers, go with Tigo optimisers and cloud monitoring if you want to see each panel. Source: my install!
Hi Great video and I like how you think. I am not a solar expert but I have a degree in Engineering Science and studied Electronics and Electrical Engineering and I am a Chartered Engineer. I have an AC coupled hybrid inverter system with solar pannels, battery storage , emergency circuits and sockets so that I can run off my batteries in the event of a power cut. I have a Zappi charger and an electric car. In my humble opinion and as I say I am no solar expert the best configuration is AC coupled. You can put CT clamps an the mains tails and that enables monitoring and fine control of the batteries charging discharging and charging of an electric car with solar divert using the Zappi. Having said that solar divert can still lead to excess solar less than 1.4kW being dumped to the grid. Essentially being wasted the best option in my humble opinion is using ct clamps on a AC coupled hybrid inverter system an eco + to maximise your own personal usage of solar and minimise grid exporting . A house earthing rod is required so that your house is independent of the grid earth so that in the event of a power cut you can use your own earth to get power out of the batteries Re optimisers if you have significant shading issues there maybe a benefit, however, pannels have an operating lifetime of circa 20 + years. Optimisers may fail after 5 years needing an expensive scaffolding deployment to replace a dodgy optimiser does rhe efficiency cover the cost of the scaffolding Moot point
Yeah, I like the ability of an AC coupled system to give you greater monitoring capabilities. But then the DC coupled systems have other advantages. There always seems to be a compromise! Still, I'm just looking forward to having the solar panels and battery storage, whatever that system ends up looking like.
This may be too expensive but I installed Solarege with optimisers on a E/W install with 2 x Tesla batteries with full offgrid back up. The advantage is that you can then go on the Octopus Tesla Tariff and buy AND sell at around 24.5p/kw/h 24/7. Thus you can put only one 13.5KW battery in and its note a concern if you are pulling from the grid or battery (other than conversation losses) Also if you have an E/W install, based on your graphic, you should also be able to install a few panels South. Remember on the 6kw solaredge invertor, you can over install upto 12KW of panels.
I did briefly consider the Tesla power wall, but ultimately decided against it for various reasons. I did like the off-grid backup functionality they offer though, it does seem to be streets ahead of any other system. Adding a few South facing panels is something I'm keeping in reserve for possible future expansion, but for now the E/W array should do us nicely.
I believe the solaredge backup is only available on a 3Ph system. Without the opitimsers, when you have a little shadow on one panel, the whole string will default to that lower panel level, it could therefore have a bigger impact than you think. One other thing is that in the peak of summer both the east and west roofs will be generating so you may reach say 6.5kw/h rates. I assume you are limiting your export to 3.68kw or are you doing a G99 application?. If you are limiting to 3.68kw and your inverter can produce 6kw, the advantage of the solaredge system is that if you are only consuming 1.5kw/h in peak summer, the 5kw extra (including the 0.5kw clipping amount that is not being considered) will be diverted straight to the batteries.
We really do have zero shadowing during 95% of the day, so I'm still undecided about the benefit of optimisers. But I can certainly see how having the monitoring functionality they give you would be super helpful, so that's something to consider too. I did actually calculate what the peak output of the E/W array would be and it came out to about 5.3 kW. We've already got DNO approval for 6 kW, so we're good to go, I believe. I do like that clipping charging mode for the SolarEdge system, but I think in reality it wouldn't help us much, although I may be wrong. I suspect whichever system we end up with we'll be happy with it overall, but also annoyed by the things we had to compromises on, as there are compromises with all of them unfortunately.
Yup, that's an option, for sure. I think I'm going to go for one battery initially and see how we get on. If I think the extra charge/discharge rate is worth it I'll certainly consider adding a second inverter if we get a second battery down the line.
@@TimAndKatsGreenWalk I have givenergy 5kw gen1 and 10x410w panels installed 22.10, works fine. I saw in peak 3800w on array so not bad like for October
@@TimAndKatsGreenWalk The benefit of installing a 2nd inverter and battery at a later date is it should be VAT free, as the inverter is PV kit. Just be careful getting a 5kW and wanting to add a second 3.6kW later as you would need DNO
If you go hybrid, the total output should be able to meet background house usage plus what the heat pump would require, plus cooking leaks etc. if you are not careful, you will still be pulling a lot for the grid, even if the sun is out. Look at your forecast demand profile through the day.
I have option two. It has been great at saving me money but as you said in the video hard to track the data correctly with the DC coupled battery. If I could go back I would have spent the extra on a Powerwall. I got the same system installed for my mother and for her it is fine she is not interested in changing her battery settings. For anyone who is considering it the settings are hidden at installer level so you have to set up as business owner in order to configure storage profiles and then assign them to the system. As mentioned in another comment SolarEdge does have a backup option but it is not being released in the UK until 2023.
At the end of the day if the system is working and helping reduce your bills it's all good. I have a suspicion that SE will open up those settings for users to play with eventually as it does seem odd to lock them away like that. And it's good to hear they're working on the back-up option.
One thing you didn’t consider is that a DC coupled system are more efficient because in affect you have DC to AC and an AC to DC in an AC coupled system that you don’t have in a DC coupled system. You didn’t consider the Fox ESS hybrid system, two of these would give you what you need, I have one of these and a Zappi car charger and it doesn’t work very well when you are charging with solar but I can still use it in the summer and in the winter charge with overnight Go rates anyway and I’m talking with MyEnergy about a fix for this DC coupled problem what can happen is the charger turns on when the batteries are full and then keep charging until the batteries are empty. In most circumstances optimizers are not much use unless you have shading in the middle of the day. The other thing I like about the Fox ESS system is they use series connected batteries, minimum capacity is 5kWh, very easy to add additional storage not so easy when you are adding more batteries to a parallel connected system as you have to worry about balancing losses in the cable runs. FYI I have a 3k8 solar array and 10kWh of batteries, unlike you I'm not going for electric heating (at the moment).
Yeah, there was a lot I didn't mention in the video, otherwise it would have been an hour long! I have heard of Fox ESS but haven't considered them for our system because they have a large footprint which I don't have room for. Otherwise they'd be a contender. I hope you manage to resolve your Zappi issues.
Hi Tim , Octopus go faster is available for 5 hours @ 8.5p per kw . If there is no shading on the array dont worry about not having optimisers . The givenergy 9.5 can only charge / discharge at 2.8kw . a hybrid inverter can simultaneously feed into the AC and DC circuits , For example the 5kw givenergy hybrid inverter can push 5kw AC into the house whilst pushing 5kw into the batteries however if you are going to get a heat pump the pump can draw up to 5kw so i would suggest a hybrid inverter of 7kw Solis 7kw fox batteries solax 7kw solax batteries A Zappi will work with any system using its own ct clamp
I was not able reach 2.8 kW. It is rated 2.6 but I saw 2.51 in peak average max is 2499w when charging and 2655 discharging. It is in utility room all the time temp there is 23-26 mean perfect like in the givenergy manual
All sounds about right to me, although I am only a newbie as well, but learning quick. As you have an East West split on your solar, does that mean you always have half your house in shade, thus needing optimizers, or if you have each side on a separate inverter, that does it not work like that? If you charge your battery and an EV overnight, will that stress your electrics, not sure if a constant 12kW for 4hrs could cause an issue? My guess is the most power hungry surprise will be your microwave. I was surprised how little each ring and oven used on our cooker. With 5kWs available, you should be able to run most things in your usual household routine. For us, running the house in a power cut is also essential, as it happens a couple of times a month.
So the way I believe it works (but I may be wrong!) is that because the different sides of the house will consist of one string each (with 9 panels on each string) those strings operate independently even though they go into the same inverter (say with the GivEnergy hybrid inverter, which has two string inputs). If they were all connected to the same string then yes, that would be a problem for sure. Regarding the stress overnight when charging up a load of things at the same time I believe we'll be alright because we have a 100A supply, so if we add up 30A for the car (11kW), 22A for the battery (5kW), 13A for the Eddi (3kW), we get 65A total, so should have enough head room. If I want to play it save the Eddi could run at 1.5kW (6.5A), and I could charge the car at only 3.5kW (15A) since we don't do many miles. And you're absolutely right, the microwave is surprisingly power hungry, our 900W microwave consumes about 1.5kW! No idea what the other 600W is being used for. The kettle is the big killer though, at 3kW. We're going to replace it with a 2.2kW one when it fails though, so that will help a bit. 5kW should be plenty for most things, as you say.
@@TimAndKatsGreenWalk 30A is only 7kW for car charging. Not an issue for your calculation on headroom on the supply, but you won't get quite as much charge into the car as you've allowed for.
@@johnmckay1423 yes, we don't do many miles at all, so 3.5kW each night for 4 hrs should be plenty as it happens. But if required we could use the full 7kW as I think that would be fine.
I am looking to keep my UPS option open too, because I've replaced my lead acid batteries with 2 x Seplos Mason 10.5kWh LFP with an out limit of 200A DC, which giving me 18kWhs of useable storage. (80% helps to prolong the life of the pack) I too need to change my Inverter as a result. I have two strings coming into the house, I have to have a dual string input on the Inverter. So I am going with the Sofar HY 6000-EP Inverter. This has a 27A AC output which fall inline with the current Inverter, but can charger higher rate of a 100A DC, as opposed to 60A DC for the old Inverter. Currently on a sunny day I can get 14kWh (September) off my 4kw solar array. Mine operate without optimiser and there is little to gain from what I can see in your application to installed them. We have 2 batteries because we have a ASHP 9kw, Quin Sunamp 9kw, some Infrared panels, and 2 EV's to charge up. We to use the over night Octopus Go tariff to aid our charging use, and so far have achieve good results. In your case I would go with option 3. We have also uprated of house fuse to 80A, I don't know if you have taken this into consideration?
That's very interesting. Yes, our house already has a 100A supply so we're good on that front. As it happens I've just agreed with our installer to go for option 3 so I'll have more to say on that in future videos as and when the installation gets underway.
I’m currently having option 3 on an east west two arrays. I have shading do we are using Tigo’s for optimisation, works out extra £50 a panel remember do on installation and no VAT. For you EPS read up on the Givenergy solutions, I’m trying to go full house manual switch, waiting for a quote but looks fairly straight forward. As for EV charger Givenergy currently have one out on beta I think which would talk to their hybrid inverter. There is also talk of a diverter in the pipeline that would do hot water .
Yup, my installer has talked me through the GivEnergy EPS options and I'm thinking of doing the same as you. Good to know you can run anything you like, as long as you're careful to stay within the limit. I need to look at their charger to see how it compares with the Zappi, which is the current plan.
Hi Tim. Based on the Datasheet for Givenergy 5kw hybrid inverter, it seems the max battery charge rate is 3.3kw (same as 3.6kw inverter) so am I correct to assume that having a 5kw inverter is not going to help with fully charging 2 x 9.5kWh batteries in let’s say 4 hours? Thanks
Yes, you're correct, the charge rate is about 3.3kW for the 5kW hybrid inverter, so that becomes your limit. We're able to nearly charge our 9.5+5.2kWh batteries in the four hour overnight cheap window so you certainly wouldn't be able to charge two 9.5s. If you can get a six hour cheap window though you'd be set.
Hello Tim, I would appreciate knowing who's doing your install and how good a job they do once you have figured out your system. Definitely worth an install video as follow up in due course. Just be careful with your ASHP , I've just had a quote that split the power consumption in three; heating mode 7944kWh/yr (SCOP 3.5 @ 50C), hot water 3082kWh/yr (SCOP 1.75 @ 50C) and Legionella cycle 7800kWh/yr (SCOP 1 @60C). So as you can see the Legionella cycle for the quoted 300l tank consumes nearly as much electricity as it does to heat the whole house. The rep went thru' the heating benefits but skirted around the water heating and Legionella cycle, it wasn't until I got the magnifying glass over the arithmetic that I spotted this. Needless to say I will not be purchasing an ASHP.
It looks as if the Legionella cycle was quoted to run purely on the immersion heater, and quite often. Worst case is raising 300L of water from 10 degrees to 60 degrees takes 4200 * 300 * (60 - 10) / 3600000 = 17.5kWh, ignoring cylinder losses which might be 1 or so kWh. Doing this every day would take 6400kWh. More modern heat pumps (Vaillant Arotherm Plus, Samsung HTLN) are able to reach 60 degrees with a COP of around 3, and once a week is sufficient, so this would use about 300kWh. Note that holding a lower tank temperature for a longer period of time (a few hours) is also effective.
Yes, absolutely, I'll be covering the install in a future video for sure. As it happens we're getting an air-to-air heat pump system fitted soon (also to be covered in a future video) so our hot water will be provided by the Eddi solar diverter device instead of from a heat pump. It's worth checking out the Heat Geek channel for more ASHP advice if you've not already. I'm surprised by your legionella cycle values, I'd have though most ASHP could do that at a decent SCOP. I don't have first hand experience of that though.
@@asabriggs6426 Thanks for your reply it is much appreciated. Legionella cycle is immersion only @60C for 30mins each week. I have seen on other vids that 60C for 1 minute each week should be enough. But the installation quote allowing for over kill (perhaps to avoid any hint of a risk to avoid litigation) is off putting.👍👍
@@TimAndKatsGreenWalk Thanks Tim. I've subscribed to the HG channel and there is much wisdom on offer. Immersion quoted for Legionella cycle to 60C rather than using the ASHP to heat to 60C. Odd.
A lot of solar PV reciewers such as Gary does Solar etc, are now saying optimisers and micro inverters are not required on newer PV due to the inbuilt diodes effectively making the optimisers \ micro inverters obsolete. The diodes manage the panels so any shading issues doesnt drag down the whole string to the output of the affected panel.
Gereat video, Tim. Option 3: The GE 5kW Hybrid will only alow you to charge at 3.6 kW (not 4.7), so your max capacity in four hours would be 14.4 kW. Out of interest, why can't you use optimisers on Option 3?
Yes, I discovered this about the 5 kW hybrid inverter shortly after I published this video! I knew I would get something wrong, so this is why I asked for corrections, which I'm very thankful for. I've also been told that optimiser from Tigo would work with option 3 but I think that actually I don't really need them in any case since we get no shading really.
@@theundertaker8273 I don't think that the Gen 2 is much better. We've just had a hybrid 5kW Gen 2 installed and max charge and discharge in the settings is 2600W. Last night I set to charge on cheap GO and max charge rate was 2456W. I had made a similar misunderstanding to Tim when I costed up a 2nd 9.5 battery. If you are planning on using cheap rate charging to charge and second battery, I would seriously consider installing 2x 3.6kW Hybrid inverters with a battery each. This means you can charge both batteries in a 4 hour window. I'm not sure how much better this would be for the PV charging of the battery, but if you have a split east west system this could make a lot of sense. The payback on 1x5wK hybrid and 2x9.5 doesn't add up by my calcs. A lot of DNOs let you have 8kW of inverter limited to 6kW. 2x3.6 hybrid is obviously within this.
@@MrLobsterfunkdaddy thanks for info. I went to gen1 because my installer was very shitty they even lied me with warranty thankfully I have offer on text and paper with 12years warranty for both but just 5 in givenergy portal. Thankfully I have 8.2 100% battery because older one was 80% and was smaller. 100% 8.2 dod is real 10.5 old was was real 8.2 -20%. I'm happy now just opened case with solicitors and with my installer about warranty. But overall after 1 month of battle with installer all working just warranty left but will be easy to win.
@@MrLobsterfunkdaddy could you check setting for inverter on the portal? There is a slider and maybe default cap I 2600 but you can extend this to 3600?
You're assuming cheap night time electricity is hear to stay! Who knows, probably, maybe? One thing is for sure it will also rise. Having a heating system providing efficiencies of 3/4/5 to 1 will limit your risk of a cheap tariff being removed. I'm not saying dash out and purchase a heat pump either. I'm also wondering what to replace my old gas boiler with that will heat my house efficiently. I have Solar and battery storage, a Sonnen unit which I had to wait more than 18 months for a repair on. If I relied on this for heating we would have been cold for 2 winters. Which ever one you choose consider asking what is the after sale service like. I would not recommend Sonnen.
Yes, true, although I'm pretty confident cheap overnight tariffs in one form or another are likely to remain available for a while. If anything I expect they'll become more common. We'll be getting a heat pump system installed within the next few weeks which is 400% efficient so we'll be good to go to ditch the gas boiler this winter with or without the batteries. That's the plan anyway! We'll cover that in a future video.
Great Video! I have an Air-Source Heat Pump and will hopefully soon get my solar and battery. Of course I don't know the size of your house and insulation status, but 15 kwH per day for heating in winter sounds too good to be true. Installers tend to mislead people about the actual usage of these pumps so I am really interested to see an update of this video once you have the pump, to see if your batteries cover all usage!
And it is too good to be true. 15kW for a heat pump over 24 hours in winter is unrealistic at best. Heat pumps will run in anti freeze mode for hours overnight. The theoretical figure is 15kW, with anti freeze running you can probably add another 10kW to your calculations. This from a 100% electric home, zero gas, A rated EPC, whole house. All underfloor except 2 x towel rails in bathrooms. 33.7kW GivEnergy battery storage, 6kW PV and still buy from grid in the winter. 😕
I have just had a 6.2kwp system installed will solaredge inverter and battery. I haven’t got the backup system but I do believe that it is possible with solaredge. On the subject of optimisers, if it was me in your position I would get the system which allows them. When you do get shading it would essentially kill the power from that whole string. Your installer would be best placed to give you advice though.
Well, it depends what your properties are. For some cost is the most important thing but for others not as much. There are other benefits beyond the cost savings that might make it worthwhile.
Personally I'd recommend a Victron inverter with pylontech batteries. They're modular, so you can add more at a later date if needed. You're very good at maths and spreadsheets, so I'm sure you've already considered this, but if you're getting solar installed, making sure you can supply the whole house electricity from batteries for the few days of the year where you have no solar at all and it's very cold is likely not the most efficient use of your money in terms of return on investment. I did some somewhat crude calculations looking at electrical demand each day vs number of pylontech 3.5kWh batteries needed to meet that demand: 4 batteries got me to something like 50% of days 5 got me to 80% 6 to 95% 7 to 98% But to get to 100% took 12 batteries. So there was definitely diminishing returns. and that 5% would never have paid for itself considering it took twice as many batteries to meet that demand. (This was batteries alone, no solar. It would have been a lot more complicated to calculate them combined.)
Yes, exactly, my latest spreadsheet answers this very question (it now includes batteries and solar so keep your eye out for the next spreadsheet video). I decided it was not worth going as high as 19 kWh but going to 14 kWh was just about cost effective. With solar, batteries, and heat pump heating it should all pay back in about 12 years, amazingly (assuming current prices). Although there are lots of simplifications and assumption in the calculation it's still more reliable than sticking your finger in the air!
SolarEdge optimised panels are fantastic, if you need them. I worry that your installer doesn't seem to be able to tell you things like "can I use this system as a backup in a power cut" - do check they are MCS accredited, as also you'll need that if you want to be paid for export. I also think both your battery sizes are too small if you want 20kwh usable a day (depth of discharge means you'll get less actual power in or out) and also you are betting a lot of money on tariffs like Octopus Go being around for 10 years +.
Yeah, I didn't mention depth of discharge as I didn't feel that it was super important to the overall point of the video, but I take your point (I do know what it means ;)) The GivEnergy 9.5 kWh state the DoD is 100% while the SolarEdge ones claim 9.7 kWh is available out of the 10 kWh stated capacity, so it's not too far off. The 20 kWh use per day figure was pretty approximate in any case, it was just a conveniently round number for the purposes of illustration. If anything I bet that time of day tariffs will become even more common over the next decade, but you're right, that is a risk. It's one I believe is acceptable though. Our installer is super busy right now (as they all are) so I'm not pestering them with every question I have right now, but in due course, once we're at the top of their list, we'll be having a thorough discussion about all of the options. In the mean time I'm doing my own research and asking strangers on the internet to help fill in the missing pieces of my understanding. So once we do get to have that discussion I will be as informed as I can be so that I ask all the relevant questions and end up with the best system for us.
Interesting video. I have a Givenergy 3.6 hybrid inverter as well as a Zappi and Havi controller. The Zappi is connected to a outside IP68 CU so the inverter cannot see it. A CT clap in the meter box tells the Myenergy software when we are exporting to the grid and takes that charge as needed. The GivEnergy system software says this is all export but the combination of these apps plus Octopus Energy app, gives me the complete data picture. Unlike you I have done this in stages which makes this a tad more challenging especially as I am now looking at removing the combi gas boiler and going all electric. The details matter and it is certainly far from easy with so many variables so our shared experiences hopefully save others from making mistakes. I have to say I have been very impressed with GivEnergy although I don't have experience of other systems as a reference. I was super impressed that a software update I suggested was implemented just 3 months later, so they clearly listen to feedback and their software both on your phone and PC is excellent.
That's great, thanks for explaining your system. It's good to know that you're impressed with GivEnergy. That's one thing I'm particularly looking forward to once we've got our system, looking at all the data etc. Our plan is to get rid of our gas boiler within the next couple of years and I think we're on track for that so far. It might actually happen next year some time with any luck. We'll be covering it all on the channel so hopefully folks will be able to decide if it's something they could do too, or not.
@@TimAndKatsGreenWalk Thanks...yes I'm on the same journey looking at heat pumps v air con and waiting on quotes on both to start the assessment. And then looking at the power implications ref our existing solar/battery system as I have space for 4 more panels which could be useful not least because it will mean zero VAT on the extra batteries that I will no doubt need. Anyway like you will be sharing my journey!
@@doingourbit8551 ah, of course! I thought I recognised your channel name. I'm sure I've seen some of your videos before but I've just made sure to subscribe too.
7kw exceeds the max dc input of givenergy 5kw hybrid inverter listed on the datasheet. This may or may not be a concern. Also the max current input is quite low on this inverter. We couldn't source any panels that would meet the listed max current rating. All this info is on the inverter datasheet.
Yes, I forgot to mention the limit of 6.5 kW DC input for the 5 kW hybrid inverter in the video. I believe that's ok though as the East/West split means the max power from the array is probably about 5.3 kW. I'd not considered the max current issue though, so thanks for bringing that to my attention. I'm going to look into that a bit more.
Agreed with regard to East West and performance....one thing I wasn't sure about was invalidating the warranty...I guess givenergy would advise on this?
Hi Tim. Regarding the optimisers. If you have an East and West panels as the sun moves around wont it cause shading issues on each set of panels at one point or another in a way that optimisers will be of some benefit as they are likely to prolong the generation period of the panels as they slowly become shaded?
AC coupled battery storage is a much better option imo. Firstly you can combine both the solar generation and the battery to output more power than a DC coupled sytem where you are restricted by the max AC discharge rate of the the inverter. Basically you get rid of that bottleneck in the system. Secondly an AC coupled battery is much more flexible in installation and when setting up with EV charge points, as you 'can't see' the DC coupled battery which is hidden behind the hybrid inverter. Thirdly the conversion losses compared to DC coupled system is nothing to lose sleep over, it's negligible. Cheers.
Interesting video. I have just selected and am having installed tomorrow the GivEnergy 9.5 battery to compliment an existing solar array. I am also putting a second new array on the back of the house. A couple of thoughts on the issues you saw. Firstly - you could always add a second GivEnergy ac inverter into the mix to give you 6kw charge and discharge. (My plan is to add a second battery into the mix once I have seen how the second solar array performs - maybe adding a second ac inverter, maybe just daisy chaining) Second thought is have you considered going down the micro inverter route for you arrays. My second array is going to be an enphase microinverter solution. Shading issues don’t exist, ultimate flexibility and maximum efficiency (and lots of panel level data).
In my last house we had a 7kW array with Enphase microinverters but no batteries. The data detail was great, but since the output of the array was AC, if we added batteries there would be a conversion loss to back to DC to charge the batteries, yes?
Yes, I did wonder about a second inverter. Since this video I've decided to go with just one battery for now and then see how it goes. If I decide I do need a second battery after all I'll certainly consider the second inverter as an option at that stage. I hadn't considered micro inverters but it's an interesting option. Probably a bit late now given where we are with our install coming up soon, but if I ever get an additional array like you I'll have a think about whether that would be a good option or not.
Great Video I have two Electric cars and a ZAPPI charger Looking at option 3 mysel, butt is it compatible with the ZAPPI, ? Two 9.5 is what I want also with a 5 kW inverter
Yes, we ultimately went with option 3, although with a 9.5 and 5.2 kWh battery as it turns out the charge rate is only 3.6 kW, not the 4.7 I said in the video (I've got loads more videos showing the install and the monthly stats etc. so you can see how it's been performing). You can set up the zappi to have a small export margin (say 100W) so that it can still work with the batteries by waiting until the batteries are full before sending excess solar to your car. Myenergi have a tips section on their website giving the details, I believe.
Hello there, finding your videos very informative . My question to you would be: other than cost, why have you not considered the Solar Edge AC coupled 10kWh storage Battery, and have you considered Mains power failure back-up?
The SE inverters are by nature hybrid when connected to their own batteries, so AC coupling would be unnecessary really. Unless you wanted to add two SE inverters which would add to the cost. I mention the backup functionality under the pros and cons lists, at the moment SE don't support it but I believe they are working on it.
When, oh when, will Sodium-Ion batteries be available to punters in the UK? This would be game-changer. All these rock-stars like Faradion et al tell us how they're going into production, revolutionizing grid storage and heavy vehicles, soon they'll be in EVs, but .. "Please can I have one for my home microgrid?" "Uh, wha.. wot dat?"
Why can’t you use optimisers with GivEnergy DC charging? Surely they just bypass individual cells? Or do they have to communicate? What is the best solution then for 3 phases - as I am limited to 4kw on each phase
Solar Edge optimisers require a Solar Edge inverter to work (it's the inverter that controls the optimisers), so you couldn't connect your panels directly to a GivEnergy hybrid inverter. However there are other types of optimisers that might work with GivEnergy inverters, such as Tigo (although I don't know much about them). There are now a handful of three phase systems available and in fact GivEnergy have recently released their own three phase system. That might be worth a look.
Fantastic video I'm installing a hybrid inverter with 13.5kw of pylontech batteries with no solar at this point. I'm interested to know how you plan to heat the house on batteries only thank you
Well, it turns out I'd need more than two batteries to cover all our heating needs for the coldest days. I've just finished editing a follow-up video showing the calculations so hopefully that'll be up in the next couple of days.
Another informative video, have you posted anything regarding G98/G99/G100 DNO applications (Costs/time/pros & cons)? Does your 5kW inverter also result in supporting higher house loads and reduce probability of needing grid power (thinking of your kettle and toaster example)? Thanks 👍🏼
No, I've not done a video about DNO applications. I don't know much about the process really, since my installer handled that. The 5 kW inverter is so far proving pretty good at keeping grid use very low but you only get the full 5 kW when you've got some solar to support the 3.6 kW you can get from the battery. In the winter we won't get the full 5 kW very often I suspect!
Thanks for the quick reply. So if battery is full and no house load your max grid export is 5kW (assuming you are generating that)? I think one of the DNO application options limits the export but I’m still researching that.
@@Stickneytube yup, G98 limits you to 3.68 kW, while G99 goes higher (although there can still be a limit imposed by the DNO). Your inverter is what determines the maximum export rates so yes, I can export 5 kW at the most. G98 is usually automatically granted, which is why a lot of standard installs keep below the 3.68 kW limit to ensure a quick and easy DNO application. If you have enough roof space for more than that though I'd go for as much as you can and put in for G99 application. It'll take longer to go through and isn't guaranteed but the extra capacity will be worth it, I reckon. You can always try ringing your DNO before deciding to see how likely they are to grant G99 approval and at what limit.
Charging overnight will pull your average kwh unit rate down. We average 8pkwh ourselves. Our setup is slightly different, we have 2 solaredge se5000 and a pair of Lux 3.6 AC coupled inverters. This allows fully charging the batteries overnight in the four hour period. The setup means on a bright sunny day we can achieve over 10kw of discharge (solar+ac inverters). The Lux provides a 16 amp EPS system which work well, however if there is a power cut we loose the solar. Anything option is victron setup with a g100 rating. This allows completely off grid but victron is not cheap. Optimisers are down to shading, we have a bit of shading on our setup which helps and this shading is down to the seasons and the height of the sun. I can show you a couple figures etc on the setup. Ours is not the cheapest setup.
I have pylontech and from experience they are very good. You can start small and add if you change your mind. Also very cost effective. If you are still flexible I recommend them
Yes, that's something I'm considering for the future but I've now decided to start with one battery and see how it goes. If I decide to add a second battery in the future this is definitely something I'll consider.
The 10kWh StorEdge battery and HD Wave inverter from SolarEdge cannot work off grid. New single phase models of battery and inverter will be released by SolarEdge next year with this capability. A three phase system already exists.
People always say that they don't need Power Optimizers as they have no shading, but what is shading? Soiling, snow, clouds, birds on modules, trees (they grow) chimneys, aerials, telephone cables that are in front of the modules. What about the other benefits? You do need Power Optimizers due to module mismatch, as each module will differ +/- 3% regardless of azimuth or tilt. Safety, with the S series Power Optimizers, they have a thermal sensor that can detect the rise in tempertature and shut the inverter down to 1 volt per Power Optimizer (SafeDC), with AFCI, you can also stop an Arc at module level, and reduce the risk of fire. What about the monitoring, you want to see what each module is doing, you would'nt drive a car without a speedo, or fuel gauge. Maintenance, being about to power your inverter down, and removing the risk of electric shock to anyone working on the roof or near the modules. You can't do that with out SolarEdge Power Optimizers.
@@TimAndKatsGreenWalk 2% added generation as you have a MPPT at each module. Over 25 years, that will cover the cost. What about Safety, and the monitoring side? How will you know if you module is underperforming or damaged? I have a difference of 27.08 kWh between my best and lowest performing module out of nine on a south facing system, in 17 months of production. A total of 132.45 kWh that i would have missed out on, if I had gone for a traditional one MPPT inverter.
A very interesting video thank you. At the moment I am still in the process of trying to source a supplier for a solar system. However if I have interpreted your video correctly you aim to meet all of your electrical power needs by charging your battery at night using cheaper electricity. Using this model do you think there would be sufficient savings to negate the need for having solar panels installed and just having a battery system? Although I recognise that this would then attract a VAT charge. Many thanks.
Good question. I am working on video covering a thorough calculation for the winter heating savings which will hopefully be ready in the next couple of weeks. That will be ignoring the summer use though. This model is primarily aimed at covering the heating requirements during the winter when there isn't sufficient solar to cover all of the electrical needs, but during the summer that's when you gain the most benefit from pairing the solar panels to the battery. Having said that you can do a quick and dirty calculation based on your average daily electricity use and then just multiply that by the difference in price between a standard flat electricity tariff and the off-peak rate to get the total savings over the year. For us that would be ~5 kWh * 365 days * (34p - 7.5p) = £484 per yr. If we got a 5 kWh battery we could cover most of our needs by charging up overnight and using that charge during the day, and it'd break even in about 10 yrs, which is the typical lifetime of the battery. This wouldn't cover heating though. In the summer (probably Mar to Oct) the solar would charge the batteries so the savings would be higher as you're not charging overnight, and you also have the opportunity to get the smart export guarantee for any excess solar you generate, so I reckon you're still better off getting solar as well. But if you can only get batteries it's worth considering, for sure.
@@TimAndKatsGreenWalk Have you chaps/chapesses seen the channel 'Gary Does Solar'? He goes into exactly this subject in depth and has created a superb spreadsheet that allows you to input your conditions to compare basic electricity with PV/battery and just battery. He links his spreadsheet so you can play with it for free. The video is: ua-cam.com/video/FvjuJQZRrvA/v-deo.html
I’m not an expert but have done research like you. I have solar edge dc. It’s very easy to monitor and works well with Zappi in my experience. Re optimisers, I understand that it’s not just about shading. It’s also relevant if a single panel in a string fails or underperforms. I can see from the monitoring app that my panels facing in the same direction differ in their production by up to 10%. I think Octopus is brilliant but I wonder how sustainable their Go tariffs i.e. are they profitable for them. At 7.5p, do they even cover transmission costs? I’ve been using the Octopus Agile tariff (not available with Go) to benefit from up to 80p per kWh at certain times over the summer. I’ve been discharging my battery fully between 5pm and 7pm each day. Cost wise, I’ve seen 9.5kw GivEnergy quotes as little as £3k as part of a solar package. My Solar Edge was nearer £8k. May be not the best choice.
Good to know the Zappi works well with DC coupled systems. For the optimisers I've seen studies that show very little difference in overall generation for short strings (7 panels or so) when there's on shading, so I'm still undecided. I think the reason it makes not much difference is that in low light a string with no optimisers will start generating earlier so you gain a little benefit there which might offset any benefit from the optimisers when the light is stronger. Anyway, whatever the reason we're in that situation where it's unclear whether they'd have a material benefit to us, so I'm not currently considering them as essential and will go without if other factors are more important (everything is a compromise!). For the overnight tariffs, I expect they'll be around for a long time, and get more popular, even if the actual numbers change. It's certainly something to keep an eye on though. Amazing that you were able to get 80p/kWh at peak times.
Our Octopus payment for solar surplus is now up to 15p per kWh. They are one of the most financially secure energy retailers so it must make sense (they are charging 34p per kWh for grid-sourced electricity)
Have you taken account of the 6kWh that you can deduct from the gas consumption and switch to your immersion heater (this would only drop the ASHP requirement by 1.5kWh due to its 400% efficiency). ALSO your ASHP could also be set to run during the 4hrs night time rates.
Yes, there are some subtleties I didn't cover as it was already a long video! But yes, running the heat pump overnight is in fact something we're already doing and I accounted for the hot water gas usage in the heating calcs.
Hello, great info and details. Question, I have been offered sunsynk 3.68 inverter and a sunsynk 5.32 battery with longi panels 12. Any views on the sunsynk against Givenergy equivalent please. Much appreciated for any comments. Thank you
The specs for the 3.68 kW Sunsynk inverter are similar to the GivEnergy 3.6 kW hybrid inverter so not much to choose between them. Ditto with the 5 kWh batteries. The main difference comes with the 5 kW inverters where the Sunsynk one beats the GivEnergy one on the battery charge and discharge rates. So for you it'll come down to price and control features. I don't know much about the Sunsynk controls but from what I've seen the app support is better for GivEnergy, so that might be a consideration for you. I'd recommend tracking down the datasheets for the two different systems and comparing them to confirm what I've said (in case I've got anything wrong). But hopefully that helps a bit.
Considering a second battery but I can’t make it make financial sense yet. Woudl be mainly for heating which means winter which means not much solar - so its off peak 7.5p vs 10p gas. Even with 400% COP the savings aren’t that high for that portion - Maybe £250 for gas for 6 months of heating vs £50 optimistically for a heat pump? I’ll definiltely add it if we have the spare money but it’ll be for ‘get off gas’ reasons rather than ‘saving money’ reasons
Yes, exactly, I'm doing this as much to try and get off gas as to save money. Having said that I've just finished editing a video showing a much more detailed calculation so hopefully that'll be up in the next day or two. It turns out it's not as clear cut as I suggested in this video!
If you need optismers Solaredge is probably the one to go with but you can use tigo optimsers though I've heard they aren't great at the commissioning stage so installers don't mention them. I would probably look at Pylontech batteries as the cost per kwh is better than both givenergy and Solaredge, linked with a victron mulitplus 2 will give good data and the pylontech batteries are modular so can be added to if you need more.
Yeah, Pylontech batteries would be an option except for the fact that they lie flat and I don't really have the space available for them. That's why I'm considering one of the vertical systems instead.
PylonTech Force L1 or L2, modular again. L1 = short and fat, L2=tall and slim. I think SolarEdge optimisers have to have one on every panel (or min of 6?), whereas Tigo, Enphase, Huawei can have individual optimiser on selected shade problem panels. Tigo are ~£50.
Some can be installed outside, although a shelter is recommended to keep the elements off. They do need a bit of space around them for ventilation too, so a small cupboard is not ideal. Mine is installed in our garage with some space around it. Some people install them in the hallway.
What are the disadvantages with pylontech ? From what I know they are top notch batteries and they are modular .. £8k for 4 us5000 and then you când add to them ...
That's a good question, and as it happens I just published a new video that includes just that: ua-cam.com/video/g0KbYqfCq1w/v-deo.html. Some days will be zero, and at most they'll probably hit 5-6 kWh in late Dec.
You asked this before and I replied to your previous question. The zappi will work alongside any battery system, yes, just look on their website for how to set it up properly to work with a battery.
Take a look at the other videos on my channel, in particular the playlist about our solar and battery system, to see all the details. In short, option 3 but a bit less battery capacity.
I’ll add my thoughts although I see this video is 6 months old so you’ve probably already chosen your solution. I have a 4kW existing FIT array and had a 10.4kW array (East and West facing) with 2x GivEnergy hybrid generation 1 5kW inverters, a 9.5 and a 5.2 battery, one on each inverter. Similar but larger than your option 3. I needed two inverters due to the number of panels, and it looked like your 3.6+3.6 arrays are actually slightly larger than a single inverter capacity. Worth noting that GE don’t officially support the twin-inverter setup I have although it does generally work ok. I think you have the overnight charge rate of option 3 wrong. My gen 1 inverter can only charge at 2.6kW, the gen 2 is better but it’s only 3.3kW. With multiple inverters each with their own battery you can get higher throughput with parallel charging. Agree batteries are important but the payback for 2nd and 3rd batteries is poor, so even though we have an ASHP we’ve not got more batteries. Do maximise the panels on your roof as the first option, cheaper add more when the scaffolding is up.
Yup, the system is all in place now. Take a look at my recent tour video for the final arrangement. We've also had the ashp in place all winter (there are many videos about that too) and everything is working great. We're able to charge at 3.6 kW with our gen 2 hybrid inverter (the new spec sheet says 3.3 as you mentioned, but ours definitely supports 3.6 so not sure what's up with that).
That's a good question and the answer is simple, I'd not heard of them before you mentioned them! They look interesting though. My installer is familiar with GivEnergy and SolarEdge so those were the options we discussed. I'll keep my eye on Growatt for future reference though, thanks for brining them to my attention.
Switch to Intelligent Octopus for 6 hours (6x3=18)? or go faster 5 hours (but slightly higher off peak rate)? I’m going single Givenergy 9.5 but already have solar so will be effectively forced to go AC coupled.
Yes, that's an option I'm looking into. At present we can't use Intelligent due to not having a compatible car or charger but it might be viable in the future if they add more cars/chargers to their list so I'm keeping an eye on it.
@@TimAndKatsGreenWalk i was on intelligent but it can be a pain for batteries - they can drain during ‘extended’ hours into a car if it’s charging. So I’m trying to switch to go faster ending at 06:30 to help with early morning heating without needing battery for that
Great video and all very interesting. It is hard to gain concrete answers. I have the same idea as you except for not using solar panels. I am on GO and I thought a Givenergy 2 x 9.5kw on the 5kw Hybrid inverter would offer about 4.6kw output x 4 hours = just under 19kw but on speaking to Givenergy they told me that of the 5kw output 1.6kw is Solar only (hence Hybrid) leaving only app 3.4 kw to charge in 4 hours = 13.6kw of charge. I then said could I use 1 x 3kw AC for each 9.5 battery pack and they said; only if they are on separate phases as there is some kind of conflict with information I did ask would it work if each battery fed separate consumer units, answer no, so this brings into question if your neighbour had the same system on the same phase could this be an issue and I was told it would be an interesting point At the moment the option may be 1x 9.5 & 1 x 5.2 = 14.7 and the Hybrid 3.6 output x 4 hrs = 14.4 fully charged. My daily normal kWh is app 20kw so either I am not at present able to fully fund peak use or wait till they have got over the issues What do you or anyone else think?
Yes, all good points. I discovered after making this video that the hybrid inverter limits the charge/discharge rate of the batteries to 3.6 kW, as you found out too, so came to the same conclusion that it's not possible to charge up two 9.5 kWh batteries in 4 hrs after all. I've also heard about the complications involved with two inverters on one phase so that seemed like a nonstarter as well. It's all very complicated! I'm now looking into the new libbi battery by myenergi, which has a higher charge rate of 4.6 kW (see my latest video), which would give 18.4 kWh of capacity after 4 hrs, so that might be worth looking into. The libbi supports up to 18.4 kWh of usable capacity (in blocks of 4.6) so that could be a good option for you perhaps (although possibly a bit more expensive than the GivEnergy system).
just to add an option 3 into the mix, you could have 2 give energy AC chargers, which gives you your requirements, and additionally you remove on option 2 & option 3 the single point of failure which the hybrid inverters, and more expandability on the batterys later should you need to store more, and instead of optimisers, you could go with micro inverters
Yes, two inverters is something I've considered and I'll mention that to our installer. I'll see what they say. Although as it happens I may be leaning back towards having only one battery, but more on that in a future video...
There is a big problem with dual inverter setups right now and Givenergy plan to launch an additional piece of hardware to better manage this setup. Also I think 3kw is max, more likely 2.8/2.9kw due to heat loss & conversion losses.
@@andypryke6750 This is part of a reply to a discussion thread on Facebook and is a response from a giv energy employee. “Dual AC coupled systems for the most part work, but there are known issues with this set-up that we’re trying to iron out right now. One system may work harder than the other, and therefore the two can become unbalanced. There is also a bug with the total calculations for the amount generated in a day, or the amount of energy used in a day. These things won’t stop the system from performing, and you’ll still get the better charge and discharge settings, but it’s important for customers to be aware of these issues going in, as we do not currently have a time frame as to when these bugs will be addressed.”….
Have you considered the Intelligent Octopus tariff, same price as Go but gives you 6 hrs at cheap rate. The tradeoff is that you say by when you want your car charged and they control the actual timing of the charging. 3x6 is 18 kwh. Also, LFP is much better for deep cycle applications like a home battery. So id go AC coupled GivEnergy.
Unfortunately the Intelligent Octopus tariff is only available for certain models of EV, which doesn't include the one we're getting. But otherwise that would be worth pursuing. I'll be keeping my eye on the list of supported EVs though, in case they add our one.
@@TimAndKatsGreenWalk For the Intelligent Octopus tariff, isn't it supported EV's OR having an Ohme Home Pro EV Car Charger with any compatible make of car that can use an Ohme, which is what I thought I read earlier today?
I just want to parse out a little arithmetic and accounting here, altho you could extract these points from T&K's excellent prez. Here goes. Typically (say Octopus; some others too) you pay /Kwh: nearly 40p peak + 10p off-peak. This single factor: off-peak vs peak - is the #1 ISSUE. It *OVERWHELMS* all else. The small print of your electric provider deal, and your home-insurance is *CRITICAL*. If your battery + heating system is correctly sized, off-peak covers nearly everything. So.. PV panels save you off-peak so under 10p/KWh. Typically, about 300 GBP/year. Batteries+inverter save you about half total single-rate spend: say 1500 GBP/year. So a battery+inverter spend of 7K5 GBP pays off in 5 years. Solar panels spend 5K GBP never pays off, if you take interest charges into account. Running your heat-pump off battery, is *CRITICAL*, and in fact, as in my case, it may not be possible to run a heat-pump at all without the battery!?! If you are forced to get 3-phase conversion, it can totally overwhelm all other costs. Still worse, provider might give you a 3-year lead time. You are at the mercy of your provider.
Yeah, I calculated we'd save about £2k a year by combining PV, batteries, and heat pump. Total cost of all that was about £22k so accounting for replacing the inverter after 10 years, it'd pay off in about 12 years. The PV and battery make the heat pump significantly cheaper to run, as you point out.
You are assuming that your batteries will be fully discharged before the nightly cheap tariff. Given that you will have a solar array that would not be a common occurrence. December will be the worst month for the solar array. My 5.9KW array generated 104Kwh. The Giv energy kit can be installed outside as it is waterproof - that is where mine is going.
I have DIY experience with power walls and solar. I use LFP batteries & Victron hardware. If the inverters you’re buying don’t contain automatic crossover switches for grid outages, Sterling sells them. Interesting you’re using Octopus Go & not Intelligent; Intelligent off-peak is 23:30 - 05:30. BTW Tesla has been using LFP batteries in their RWD cars since Sept. ‘21.
Yeah, I've looked into Intelligent but at present they don't support all cars or chargers, so we wouldn't be able to use it at the moment. Hopefully they'll add more supported cars and chargers in due course though, so I'm keeping my eye on it, for sure. I recently found out about Tesla using LFP batteries, which is very interesting. I wonder if more EVs will start using them in future.
This presents as if it is an advert for GivEnergy under the guise of being objective. Tim obfuscates when SolarEdge has an advantage - for instance the solaredge option does have power cut backup.
I'm sorry it came across that way to you. That was not my intention and this is not an advert. This is also an old video now so things will have changed since I published it. I also said I didn't know if solaredge had power cut backup or not, as I couldn't find that information at the time.
Octopus Go is only available if you have an electric vehicle (and it it has to be one of a few selected models & you have Octopus recommended charger unit).
There are so many batteries out there now if I included every one in this video it'd be 5 hours long. I did look at the LG Chem batteries but they weren't ones my installer worked with. These were the two types they did so these are the ones I compared.
@@TimAndKatsGreenWalk there you go I’ve learnt something today. Inverters, have you looked at the Sun Synk 3.6 or above which has most of your requirements built in.
@@wakkadakkaify option 3 but with a 9.5 + 5.2 kWh battery combo. I did some more detailed calculations and decided two 9.5s were unnecessary, and I couldn't charge them in 4 hrs anyway (see more recent videos about that).
Very interesting. I too have been through this and have similar objectives. I mainly considered GivEnergy and Huawei. I've gone with a Huawei system 15kWh battery with 6kWh hybrid inverter from 8kWh PV powering a heat pump and also on Octopus Go with a Zappi and Eddie.
The battery technology is the same Lithium iron phosphate (LiFePO4) but the Huawei is a high voltage battery at around 385V instead of GivEnergy 50V. The advantage with the Huawei inverter is that it can power the house with AC at 6kW max from solar whilst the battery simultaneously charges at 5kW (if there was enough solar!) and the battery can provide 5kW output. Whereas GivEnergy's hybrid shares it's 5kW maximum rating also it can only charge or discharge the battery at 2.5kW max. So if the house load was 4kW you'd only get 1kW into the battery. If your house load was 1kW you'd only get 2.5kW into the battery - so your solar goes to waste. I also found it was slow to ramp up, so every time you switch something on the first 16 seconds or so of extra demand is fed from the grid before the solar or battery ramps up to 100% of demand. All these spikes of grid energy add up during the day. That was when I enquired early in the year and they may have improved the spec as they recognised it was a disadvantage.
The Huawei is much faster to respond so doesn't clock up all those initial load switches.
The Huawei can provide grid tied mode which goes into standby when the grid fails, automatic backup (with an additional backup box) mode which is meant to keep critical circuits going, and a full off grid working mode. Theoretically the full off grid mode could power your house up to 5kW but as with any system primarily working grid tied it has to shut down or isolate when the grid fails otherwise it will attempt powering the grid which could be a safety issue down the line at a wire break that's expected to be dead.
You are right to not be concerned about optimisers. As I was reminded only the other day, there are reverse biased connected diodes in solar panels to ensure that if a column of PV cells goes high impedance due to, say a leaf falling on a cell, the cell is protected from becoming reverse biased by the combined voltage of all the other panels in the string which could add to a high voltage. The diode becomes forward biased instead which limits the reversal and the current bypasses the affected column so the affected cell is only reverse biased by the other fewer cells in the column. So PV panels automatically optimise to an extent anyway. You may lose a couple of columns from a leaf but not the whole panel. If the shadow crosses all columns the panel output will be lost but the other diodes in that panel bypas the current so the whole string only losses the output of one panel and the impedance it's kept low allowing the inverter to maintain optimised power transfer.
Where individual optimisers help is where there is partial shading of one or more panels, perhaps through a tree canopy or dirt film, not enough to switch off the cells completely but raising the impedance of the working panels. The cells don't become reverse biased and the diodes don't bypass the current but the raised impedance can cause the inverter to limit the power draw from the whole string as it starts to see the voltage collapse under load.
Optimisers maintain some useful output from the affected panels but don't don't raise the impedance of that section and the whole series connected string, which would loose more power. Power is usually optimised in the inverter by taking increasing current from the string until the voltage voltage starts to fall so it finds the sweet spot for voltage x current = power maximum (MPPT maximum power point tracking). Optimisers can cost as much as the panels though.
Anyway, It's just seen you have another video about a second battery and spreadsheet calculations - something else I've been through sizing mine.
That's very interesting, I hadn't looked into the Huawei system in too much detail before, so you've given me something to think about. Thanks for explaining your system. Good to know that it can do power-cut back-up if needed too.
I saw a good video this week by Gary Does Solar on optimisers explaining it in the same way as you and that makes a lot of sense. I'm pretty confident I don't need them now.
@@TimAndKatsGreenWalk Yes, it was Gary's video that reminded me about the protection diodes. He explains very well how it effectively optimises. I remember them being explained as reverse bias protection in a lecture many years ago but I'd forgotten.
@@johnh9449 yes, Gary's videos are excellent. A level of quality I aspire to.
SolarEdge Energy Bank does allow backup, you just need the right inverter and a backup module. Other advantage that makes a big difference is that any generation that would normally be clipped by the inverter is used to charge the battery so if your 6kW array is maxing out and you have a 5kW inverter the extra kW goes into the battery instead of being clipped and effectively wasted
Yes, I'd seen that about the SolarEdge system, quite a neat feature. I've calculated that our E/W array will max out at about 5.3 kW so possibly not super relevant for us, but neat nonetheless.
@@Dr4co2023 oh, nice, that's good to know, thanks.
It only allows backup in it's three phase inverter. For single phase you need to wait till the reales next year of the 'Home HUB' with a backup interface.
I have your option 3 being installed hopefully next month. I believe the hybrid inverters are also more efficient than AC systems as there isn't as many DC to AC conversions involved. The other consideration for me was that the Givenergy system can be completely controlled locally without internet through the modbus interface that in my case will be going to Home Assistant. I believe this is important not only for system longevity but for control during a blackout when the internet might also go down. Time will tell if I've chosen wisely.
Yes indeed, I hope it works out well for you.
SolarEdge inverters support Modbus
@@jerseyman99 I am having a Solar Edge system fitted and chose that because I use HomeAssistant extensively and I understood the Solar Edge system could be completely controlled off-line via the Modbus. but Tim's Conversation with John I saw yesterday said not. Can you point me to any good recourses please. I literally paid the deposit yesterday!
I had similar requirements for myself and went with the following i) Solar is AC coupled using the cheapest Solis inverters ii) Battery is AC coupled with Victron Multiplus . This configuration keeps me lock in free from any brand ecosystem. Further Victron multiplus is fully open / programmable system and I am integrating it part by part to my homeassistant setup. Victron will also provide support for power outages if wired that way. Build quality of victron is like a tank ! and that's what I wanted for such a busy device in this mix. For battery , personally I built it myself ( 2 X 12kwh LFP) but commercial options such as Pylontech are economical enough.
This is my ideal setup, but it's a bit more money so I'm saving up! I want off-grid for a few circuits for sure.
I like the idea of a more modular system, plus when my cheap Sofar inverter dies one day there's always the option of bringing the DC from the solar into the MultiPlus-II via MPPTs to allow a hybrid-like setup and total control over each element.
Just want to know have you ever thought about hybrid all in one battery energy storage system? This is somehow like one for all
Would you be able to share what exactly you have purchased in regards to the inverter battery , please ?
@@lianapilat2910 They were self built using the SEPLOS kit
Hybrid inverter without opttimister will be significantly less efficient. Though you might have little shading from trees, you will have significant shading early morning / late evening from the roof itself. Half the panels will generate very little, which without optimisation will drag the whole system down. SolarEdge also have a very powerful app, are firesafe, and their new home-hub inverter coming out within the next month will give great data. I'm planning to install int he spring.
Two separate strings mean the two sides of the roof operate independently.
@@TimAndKatsGreenWalk I stand corrected. Had not considered that. Also worth bearing in mind ability of system to be grouped together to work as a Virtual Power Plant. I don't know whether Octopus do this yet, but expect they will soon if not already. SolarEdge have had success in USA in grouping many of their home storage systems to gain revenue for homeowner and claim superior value in their speed of response. Believe several trials have been done in UK but not yet sure whether this is commercially available.
Givenergy Hybrid Inverter still limits you to a max charge (when charging solely from the Grid) of 3.6 KW. And max discharge of 3.6KW from your battery to your house. So even with two 9.5KW GivEnergy batteries you are still limited to 3.6kw limit when charging solely from grid.
The Hybrid Inverter 5KW figure is when you combine that with solar generation. Battery is always limited to 3.6KW discharge and charge when using the 5KW Hybrid Inverter
Yes, I was alerted to this fact by another commenter yesterday. That might well change my plans, I'm going to do some more calculations and follow this up with another video soon, hopefully.
The 3.6kW charge / discharge is only if you have a Gen 2 hybrid inverter, it is limited to 2.6kW on the Gen 1 version as I found out when I boiled the kettle to celebrate my installation and found I was importing power!
@@tonycooper7139 oh how frustrating for you! If we do go for that option I'll make sure to get a gen 2 inverter.
@@TimAndKatsGreenWalk so true, it still grates every time as I was expecting to be able to draw 5kW. You might want to have a look at the reviews of the GivEnergy battery before committing to that route
@@tonycooper7139 indeed. It seems every system has a compromise somewhere. No one system does everything we would like.
Interesting to listen to your thought process Tim. I have just ordered a GivEnergy 3.6kW Hybrid Inverter, 9.6kW GivEnergy battery, Zappi, Eddi & 10 x 415watt solar panels. Like you I have no shading issues & all my panels are on one side of our roof facing 122 degrees SE. I could put a few more panels on the front of my roof to catch the late afternoon sun but I decided to keep the front of the house free of any solar accoutrements.
Unlike you I have no plans to go down the Heat Pump route for home heating because our microbore heating pipework is far too small (10mm) & the cost & upheaval to rip it all out & replace it is prohibitive. I do have a small 4kW Air to Air Heat Pump in our conservatory which does a fine job of making it an all year round living space.
So, on that basis I'm hoping that a combination of night rate electric & daytime solar should keep the battery & hot water topped up for most of what we use during the day & some free vehicle charging when needed - when we get an EV that is.
As a retired couple we are at home most days which means we probably use more energy during the day than others who may be at work. That said there's only two of us now & we have started scheduling washing machine & Dishwasher etc to run over night instead of during the day. That may change when the solar system arrives. If I find we are using more energy than our battery & solar can deliver I guess an extra battery for more storage would be an option. However, as you pointed out, the max charge rate of our planned 3.6kW Hybrid Inverter would not be enough to charge anything much more than the planned 9.6kW battery during the 4hr night rate window. Do I need to go up to a 5.6kW Hybrid Inverter? I am also deliberating on where to put the Inverter & battery, in the garage or in the loft. My garage is small & is already rammed with stuff so a major clear out would be required to make some space. However, I've heard that a loft location for batteries & inverters is not the best for component reliability due to the high / low summer / winter temperature cycles. We also need a new consumer unit & our DNO needs to unloop our incoming mains electric supply from my neighbour before we can use the Zappi. I also need a new hot water cylinder because my 38 year old cylinder & immersion heater are well past their sell by date! I'm also in the process of installing a Tado smart system for our boiler, HW & radiators. This going green lark is starting to get a bit complicated & rather expensive.
Yes, indeed, it's quite a complicated and costly business for sure!
As it happens we've gone for an air-to-air heat pump system rather than air-to-water because of similar issues with pipes etc. This way was far less intrusive and it'll also enable us to get rid of our radiators, which will free up a fair amount of wall space (and we'll get cooling in the summer as a bonus). I'm planning on doing a video about all that at some point soon.
I don't think you'd get a faster charge rate from the 5 kW inverter, the charge and discharge rates are the same according to the data sheet (2.6 kW for both gen 1 hybrid inverters, 3.6 kW for both gen 2 hybrid inverters), so the 3.6 kW one is probably fine for you.
Thankfully we have enough space in our garage for the equipment but I have a friend who has their battery in the loft and hasn't had any trouble with it so far, but I don't know what the long term issues might be. We're just waiting for it to all become available now, which seems to be taking forever!
Good luck with your system and all your other plans!
@@TimAndKatsGreenWalk I have now decided that the garage is the place for the solar gear so I need to start re-organizing to make some space. I feel a visit to the local dump might be in order!
I look forward to the video on your air to air HP system(s). I spent 45 years in the Air Con / refrigeration industry as a product design engineer / manager & in sales so I know all about the pros & cons of A2A & A2W heat pumps & many other systems besides. Heat pumps have been around forever & I remember selling selling large single packaged rooftop mounted ducted systems to many high street chain stores as far back as the early 1970's. A2W heat pumps (& to a lesser extent Water to Water / Ground loop) heat pumps are fine for new build homes but to retrofit them to older houses is far more difficult as well being more expensive. That said Air 2 Air heat pump split systems with ducted or hi / low wall type indoor units that cool as well as heat are becoming very popular for home workers who want to have the same facilities at home as they might enjoy in an office building or indeed the car that they drive. It's ironic that in the 17+ years that I was based from home rather than an office, I never had AC in my home work place - & still don't. The high wall split I have in my conservatory was a retirement present from the last company I worked for. LOL.
Keep producing & sharing your videos because it's so important to have a balanced range of views & information about all subjects on YT for everyone to access & learn from.
@@colingoode3702 ha! That's very interesting. Well, I can say that so far we're very pleased with the A2A system, it's been very effective at keeping the house at a nice steady temperature with very little power usage, so exactly what we were after. I'm also very much looking forward to next summer when we get another heat wave and I can run the air conditioning for free using our solar panels (assuming they actually get installed by then)! I work from home so could have definitely done with the ability to knock a couple of degrees off the office temperature earlier this year. Thanks for your support and there will be plenty more videos coming in the future. There's still a lot we'd like to talk about and it seems a fair number of folks are interested to hear about it too, which is very nice to know.
Whilst the efficiencies you quoted for an air source heat pump are well known the actual energy use is affected by the heat losses in the house and the method you are using to transfer the heat eg. radiators, underfloor etc. We have a 4 bedroom house with underfloor heating upstairs and downstairs (EPC Rating A) and have used a heat pump for the last 12 years. In winter the worst case use is between 40Kw and 55Kw hours per day. Having said that we have replaced the old Worcester Bosch unit with an 11Kw Daikin this year so hopefully, that will be more efficient.
Yes, that's true, my numbers are an assumption based on having used ~60 kWh per day last winter using the gas boiler, and converting to a heat pump with an assumed efficiency of ~400% (which is the quoted efficiency of the system we plan on getting). What we actually end up using once we switch to that heat pump system will be the subject of a future video!
About optimizers: I had the same thought for our house, hardly any obstacles so why not make a 'bare' string and save on the optimizers (~70 euros per panel!).
However, we decided to install them anyway based on advice from our installer, because these optimizers will *always* help when clouds come in play... after 3+ months now we can see that the amount of days with unobstructed full sunshine is very small, most of the time there is some (scattered) cloud cover.
I'd have thought cloud cover would affect both optimised and un-optimised arrays to a similar degree? The optimisers help when part of the array is shaded rather than the whole array, I thought. I guess there'd be brief window of time when clouds are passing over part of the array but most of the time they'd either cover the full array or none, given the typical size of a cloud. What I wish I could do is have two identical arrays for a year and test out the difference, but that's not really possible unfortunately!
@@TimAndKatsGreenWalk Yeah, no AB tests here unfortunately.
One thing I forgot to mention is the way that these optimizers work together with the inverter: each panel reports its instantaneous wattage, and the inverter adds this together for the total amperage. Each optimizer can now calculate its share of the voltage (total voltage is always 400V) to reach this optimal current value.
The total system now has a 'constant' voltage of 400V but fluctuating current, this makes it easier for the inverter to be efficient.
With such a setup it doesn't matter much if angle of incidence, cloud cover or other obstructions limit individual panels.
My layout has panels facing east, south and west - all in the same string!
@@diatonicdelirium1743 ah, yes, if they're all on the same string but facing different directions that'd definitely require optimisers. We'll have separate strings for East and West so not so important, I think.
I have recently had installed a 7.7Kw system almost identical to your option 1. However, I use excess solar to charge the batteries during the day up to about 80% at roughly mid day, then I "pause" the Givenergy battery so the excess solar charges my car. Once there is no excess solar, I restart the battery to supply our home. The solar panels have been in since May, but the battery system was only installed last week. During this last week, we have imported ZERO Kwh, so from that point of view, the system is doing what we expected so far.
That's excellent, I'm pleased to hear that. I hope to achieve similar performance with our system when it eventually gets installed!
OK Tim, this is my system for comparison. 6.4kW solar, evenly split facing east and west, with optimisers for each panel. I have a Tesla 13.5kWh battery, which I've set to only 10% minimum for power outage backup. I have a Solar Energy inverter, 6kW output. Heating is via Ecodan 8.5kW ASHP with underfloor heating to ground floor, radiators in bedrooms. Live in a 4 bed house built 2021, ~2k sq ft. First, forget the claimed efficiencies for ASHP. In winter, when temperature is around 0° during the day and the atmosphere is very damp (say thin fog), the ASHP runs continuously and freezes. Before I installed battery and solar this year, last winter my worst day I had 84kWh usage, this did not include car charging, and probably averaged ~60kWh when daytime temperature
Wow, thanks for all the information, that's very helpful. I have heard that about the Powerwall, that it's more difficult to make it do what you want, so that's something I'm bearing in mind with these other options. I'll be making sure that my installer gives me as much control over the system as possible.
Also interesting to hear about your heat pump. We're going to be getting air-to-air, for various reasons that I won't go into here (saving that for a future video), so I'll make sure to ask our installer about freezing. I'm also in the process of building a little tool to help better calculate how variation from day to day in the required usage will impact the costs/savings, so it will account for days of very high usage. It's going to be interesting to see how that turns out (again, that'll appear in a future video). I'm committed to ditching gas and I believe heat pumps are still the most efficient way to do that, but part of the reason that I started this channel is to show a real world example of how this stuff works in practice so if I make a huge mistake at least others can learn from it! I guess time will tell.
I used tigo optimisers on each of my 17 panels and it has been great to understand what is happening.
I have option 2 SolarEdge Energy Bank with 3.68KW SE inverter and about 6KW of PV. Only had one issue so far, battery lost communication with the inverter for a few hours one day. We use about 9KWh a day and the Energy Bank should cover our usage 95% of the time. In the future I may add the back up module. I am currently waiting on Octopus to switch us over to the Go Faster tariff.
I will add that so far the SolarEdge support has been excellent, they usually respond within 24 hours. The SE monitoring portal and app are also so very good, for me at least. At the moment you cannot set the battery to charge from the grid overnight via the Home Owner SE portal, you have to ask your installer to set it up. There is an update due later this year to allow home owners to do it via the portal and app.
Good to know. I expect the user experience for all of these systems will gradually improve over time.
Very interested in your excellent home storage presentation - Thanks. Just installed yesterday a Solarfast system with 8 Hanchu ESS LV batteries at 3.2 Kwh. (Total 25.6 Kwh) coupled with a Luxpower TEK Inverter. This is now linked to our existing 16 solar panels installed approx 11 years ago. We are hopefully downloading overnight at off peak rates at 3.5Kwh per hour (7 hours) with a maximum of 24.5 Kwh to cover daytime use including an electric Aga. We are using Octopus Energy. So far in 24 hours the system is doing what we expected without the benefit of much Solar input.
Wow, that's fantastic! I've ultimately decided to go for a 9.5 + 5.2 kWh battery so somewhat smaller than your monster system, I'm very jealous. I'm glad it's working out how you expected.
I've made a three part review on the SolarEdge Energy Bank. You can find them on my UA-cam channel.
My opinion:
Get a Pylontech AC coupled battery with a Solis/Solax inverter.
Both SolarEdge and GivEnergy only allow configuration options to be accessed by the Installer. You have no access as a homeowner. In the case of GivEnergy, your warranty is also conditional of all work being done by a GivEnergy approved installer. Now at the moment, SolarEdge only allow installers access to Charge/Discharge battery profiling. That will change soon, but it is a demonstration of how little thought that they have put into how system owners want to use their batteries.
Another problem with SolarEdge - your original installer has exclusive access privileges to carry out any further modifications to your system. So if you want to use another installer to add more solar panels, only the original installer can assign rights to your new installer. The new installer cannot adopt your inverter into their SolarEdge portfolio otherwise. That's a really poor philosophy. System owners, not installers should be the kings and queens of their system.
Finally, there's no off grid backup option with the Energy Bank in the European single phase market. That's not a deal breaker, but if you're rural, or gas rationing starts to become a problem, it could be.
As for roundtrip efficiency: They claim 94%. However when I aggregate charge/discharge throughput data, after a week I'm measuring 76% round trip. I'll be reporting on that in my next video, but I'll want to gather more data.
I agree, system owners should have better control over everything. Hopefully things will move more in that direction as the industry matures.
As it happens I've already watched all three of your SolarEdge Energy Bank videos with great interest and am looking forward to any future videos about your system. I asked a question on your first video about the grid back-up functionality, and your answer was very helpful and actually informed part of this video (along with some independent research, of course).
I'm now leaning towards only getting one battery in the first instance, whichever type that happens to be, and then gather data over the winter to see how it performs in reality before making any further decisions. I'm also in the process of building a toy model to help simulate the winter usage to see how much benefit we'd get from different configurations, and to give a better estimate of the costs and savings. Hopefully that will be covered in a future video within the next few weeks.
Regarding Pylontech batteries, in principle that would be great but they have an annoying large footprint which I don't really have sufficient room for, so I'd prefer one of the more vertical style batteries, like SolarEdge or GivEnergy. I'll certainly be asking my installer to give me as much access as possible to whatever system we end up getting.
Thanks - very early in the implementation process but support to date has been excellent. Fortunately asked questions concerning limits on the download process. Your podcast would also have helped!! Ended up selecting the maximum battery storage for the inverter. May well have over specified!! At the moment 55% capacity available at 1500. The combination is also working with the myenergi for our Hybrid.
Very nice. I think with this sort of stuff you'll never be disappointed with "the maximum possible capacity"!
Been through the same thought process and currently installing the GivEnergy 5kW hybrid inverter with 3 off 5 kWh GivEnergy batteries. This is for 14 panels on an unshaded South facing roof. Factors were cost, total capacity, peak current (I have some very power-hungry machines), and also the 2kW supply in a mains outage.
Sounds good, I hope it works out well.
Does that 2kw power cut supply work straight out of the box or does the installer have to install a change over switch ?
@@munirshafi2647 The GivEnergy hybrid inverter provides a couple of socket outlets which are installed with the inverter and do work out of the box. I just have mine with an extension cable leading to critical items - WifFi, Boiler, CH controls etc. At considerably more expense you can get the installer to wire the supply into the critical circuits in the consumer unit. I think this is only possible if you design your whole electrical system with this in mind, as critical items will typically share a ring-main with non-critical items so it's impossible to manage the load down to 2kW.
@@munirshafi2647 Sorry, should have added, if wired into the consumer unit something would be required to isolate from the incoming mains to avoid back-feed. This is not required if you just use the sockets provided as the inverter provides this function.
Check out the MyEnergi battery announcement this week, The Libbi. Its capable of multiple battery storage stacking and back up during a power cut on a single circuit (so plugs or lights etc). I think the batteries max is 20kwh.
Yup, I saw that yesterday! Looks very interesting.
I wouldn't be hung up by the SolarEdge optimisers. Sure, monitoring is nice to have but if they go wrong then it's expensive to fix, unless you get them installed in the loft or don't require scaffolding to get to the roof.
Plus people have made a few good points on UA-cam that they actually do very little to improve efficiency, as you've alluded to.
Twin GivEnergy inverters seems
to be your answer, but at present it's buggy but GE are apparently working on a fix. Some people already have this setup and it doubles the charge / discharge rate so would solve your problem.
I'm going for 1 X 9.5 battery now to see how get on with the possibility of adding another battery /.inverter at a later date. Hoping the price of batteries drop as well so that might negate the 0% VAT loss. Plus with a bit of luck GE might bring out a Gen2 AC inverter next year with better charge rates.
Yeah, I'm starting to think one battery to start with then see how we get on. As you say, the technology is likely to improve and get cheaper.
I have 14x400w Sunpower
panels with SolarEdge optimisers installed on my SE facing roof on Sep 2021. Coupled with an Eddi, Zappi, 5kW SolarEdge inverter and 8.2 AC coupled GivEnergy battery. I’m now waiting on my installer to add an additional 9.5kwh battery with a second inverter so that like you I can charge both batteries fully overnight. I had my one year anniversary last month and generated 5.6MWh and used 4.266MWh of that.
@@garyday615 very nice. I think I'm going to ask my installer about the option to use a second inverter at a later time as that does sound promising. I'll be interested to hear how you get on with that configuration.
Re SE optimisers. For our 4kwp system installed in 2015, we had an MCS forecast of 3400kwh/year and the system has generated between 3500-3700kwh/year since install. Thats with 2 out of 16 panels being shaded by a chimney for half the day that wasnt included in the MCS forecast. When you consider all the shading you could encounter, I wouldnt install a system without optimisers/micro inverters. Shading includes a patch of saharan dust, a patch of algae, a dollop of bird s**t, birds perching, fixed objects, neighbours growing trees, passing clouds.
@@philedge2372 yup, all good points to consider.
Sorry a bit late to the party here. A few very important things to note:
The size of the inverter can impact how much electricity you can draw at any one time. These numbers ARE IMPORTANT.
Giv-AC 3.0 - Max DC Power - N/A, Maximum Charge/Discharge 3kw
Gen 1 Hybrid
Giv-HY 3.6 - Max DC Power - 4.5kw, Max Battery Output 2.6kw, Max Solar + Battery 3.6kw
Giv-HY 5.0 - Max DC Power - 6.5kw, Max Battery Output 2.6kw, Max Solar + Battery 5kw
Gen 2 Hybrid
Giv-HY 3.6 - Max DC Power - 4.7kw, Max Battery Output 3.6kw, Max Solar + Battery 3.6kw
Giv-HY 5.0 - Max DC Power - 6.5kw, Max Battery Output 5.0kw, Max Solar + Battery 5kw
Option 1, your correct that the AC is limited to 3kw draw in either direction.
Option 2 I suspect is MUCH more expensive than 1.
Optimisers are a waste of money, adding a LOT of cost and added complexity of install and maintenance.
Please watch these two videos for why.
ua-cam.com/video/6Ucb-f8YPuo/v-deo.html
ua-cam.com/video/E9NVLB_OYSU/v-deo.html
Option 3. For powercut protection you need to specifically have an "islanding" mode installation. This essentially would give you a few sockets that allow you to run essential devices. It DOES NOT run your house and would be limited to about 3kw (ie 13a fused plug) per socket.
The only device, currenntly, that does this is the Tesla Powerwall, although I am sure there are more products coming from other suppliers (pretty certain that these are available in different countries already Australia and South Africa come to mind).
For an easy answer I would probably go with an AC GIvEnergy & Battery system combined with a DC Coupled system & Battery
Actually, the Gen 2 hybrid 5 kW inverter specifies 3.6 kW max charge/discharge rate for connected batteries not 5 kW, according to the data sheet, so it's the same as the 3.6 kW hybrid. I added a note to that effect in the description after I found out but I don't think many people spot that! The 5 kW output is reached by combining solar and battery though. I'm also aware of the need for extra electrical work to allow for the power-cut back-up, and that it's not the whole house that's covered, but thanks for making sure. Even the powerwall will be limited to 5 kW in islanding mode though, so you'd still have to be careful not to exceed that in a power-cut. Several other systems also have 5 kW power-cut back-up ratings but usually you'd set them up with a few circuits backed-up rather than the whole house to reduce the risk of exceeding the limit. I've decided to go with option 3 since I made this video, with back-up on some critical circuits, since I agree that for our situation optimisers aren't necessary.
We have a 5.4kWp solar PV array, Tesla Powerwall 2, Myenergi Eddi & Zappi and ASHP. Our ASHP and EV were later additions. Consequently, the solar PV and battery are now undersized, even using Octopus Go overnight electricity to supplement the solar. Our DNO is blocking our application for additional solar PV so we are likely to purchase another Powerwall to cover our winter consumption.
Ah, that's a shame the DNO are blocking you. I hope that the second battery helps though.
Sadly a Tesla battery is part of your DNO allowance. The only option you have is a DC battery.
Great video, simply for garnering a wealth of informative answers in the comments! Thanks.
Thank you. Indeed one of the reasons I started this channel was to hopefully learn more from other folks, and that is exactly what's happening!
Thanks for the video Tim, I am glad I found your channel. I too have an E/W facing roof, and for that reason not going for solar, but only a battery solution. I too want to cover both electricity and heating at some point, which is why I am looking at a modular battery solution for now. Using the smart meter data for the past year, I can see we use on average 13kWh per day for electricity throughout the the year. I am also on Octopus Go, currently charge the EV during the 4 hours, and want to also charge batteries. The solution I have been looking at consists of 5 x US3000 Pylontech 3.5kWh batteries (48v) and a Victron Inverter 48/5000 (5000va) 48 volts with a Victron Gx device for the smart connectivity, however I am being told by various shops that this type of setup is for off-the-grid and will be hard to get installed, as they are trying to push GivEnergy products. From what I have read and watched on GivEnergy solutions, a lot more mixed reviews regarding the software side of things, which is my concern. An alternative solution with less hassle is Powerwall 2 with the gateway. Slightly more expensive, although I hear there is a big delay in getting PW installed. I've subscribed as I am very keen to see what you do next.
Yeah, I think there is still a lot of improvement to be made by a lot of battery manufacturers on the software side, which I can only hope will improve over time. I've got a friend who has a GivEnergy system and they're pretty happy with it so far. I considered a Powerwall 2 early on but decided against it in the end as I'd prefer to have a bit more control over how it operates. I hear they tend to do what they want rather than what you want, but perhaps there are ways around that. I'd love to be fully off-grid but that's not particularly practical for us right now. Maybe one day.
I'd consider adding solar panels even though you have an E/W facing roof. That arrangement actually has quite a lot of benefits in terms of providing power over a wider span of time through the day, while only losing about 30% of the peak power, and maybe 25% of the total energy generation compared to a South facing roof. I'm actually quite glad we have an E/W roof now, having learnt more about the benefits.
Good luck with your system, I'm sure you'll find a good solution eventually, and I'll be sure to let everyone know how I get on in future videos, regardless of they system we end up with.
I do have an E/W facing roof with roughly 3.7kWh of Solar PV on each side. This is actually a really good way of maximising solar output to power the home for more of the day. I have had my panels for West facing panels for around 11 years and 3 years ago, I added the East roof solar panels and a Tesla Powerwall 2, Eddi and Zappi. (eddi replaced an older water heater!)
In the summer within half on hour of sunrise the panels are giving 1 kWh of energy and same at half hour before before sunset. It tends to give around 3.5kWh with a blip to near 5 just after midday as the sun is on both sides of the roof.
For info, in 2021 I recorded 5747.5kWh of solar production. Using the Powerwall 2, I managed an 89% Night rate use, so it was very cost effective. I have since added an ASHP and this will be my first winter with it.
@@Jaw0lf very nice. Sounds like a good setup.
@@Jaw0lf very useful comment. What is your winter experience with the heat pump? I am planning to install one soon
@@DahouiM Thanks and glad the information is helpful. We have found that during the winter the ASHP has kept us nice and warm, no problems at all when the temperature went into the negative numbers. Following researching as much as I could, I run the ASHP 24 hours per day, well the temp is set all day and it comes on as needed! We have set the home at 18c and it drops by just 2c overnight. Maintaining a core temperature for the home seems to be the key factor due to the lower flow temperature. Running the heating at 19c was too warm for me and it was jumper on/off all the time, so dropping to 18c was perfect with an extra layer!
To confirm, our cavity wall has little to no insulation at the moment so my 1st year will have used more and we have a 5 bed detatched house. Our energy use for Domestic hot Water and heating has been around 3600kWh for the 12 months.
The cavity insulation is being sorted for us next week and I am hoping to see maybe a 20-30% reduction in our use, when this is completed.
You can use tigo optimisers if you really need them due to shading with the GivEnergy Hybrid system. You can optionally install a tigo monitoring module into the string for viewing performance over the internet. I thought there is a GivEnergy portal for this already though?
You’d need to get the GivEnergy EV charger for you to balance/manage supply between your EV and DC batteries. The Zappi can’t monitor DC.
Heat pumps, look at daikin, specifically the solar pv/smart grid functionality. They can be triggered by your GivEnergy system when there is excess to heat the home or hot water. You’d need to get the GivEnergy smart plug and set the limit statically on the Daikin HP, say 1.5kW. Pretty much all Atherma 3 HP’s now have the solar PV/smart grid functionality. You can optionally install a smart meter with the Daikin HP to dynamically modulate it’s output to match PV generation, but I’ve found it jumps out of this window when heating hot water, a static limit is more deterministic and simpler to install/setup.
I’m on intelligent octopus and heat the hot water tank at night with the HP. And I boost the house temp a couple of degrees.
Interesting about the Tigo optimisers, I'll bear that in mind, thanks.
The more useful aspect of optimisers in general, SolarEdge or Tigo, is that they can optimise multiple aspects on the same string. So if you wanted to do the south facing roof, along with your existing design you could. It may well be more optimal to have two rows of panels on all southern aspects, than three solely fitted to your south east/west roofs.
You are going to need two of either gen1 or gen2 Givenergy inverters, one for each of your batteries to meet off peak charging requirements. This could be set up with East on one set, West on the other.
The only real difference of gen1 to gen2 would be the combined charge/discharge rate of 5.2kW Vs 7.2kW ( and ethernet/WiFi built in gen2).
If you're wanting optimisers, go with Tigo optimisers and cloud monitoring if you want to see each panel.
Source: my install!
Yup, I didn't talk about double inverter setups but that is a consideration.
Hi Great video and I like how you think. I am not a solar expert but I have a degree in Engineering Science and studied Electronics and Electrical Engineering and I am a Chartered Engineer. I have an AC coupled hybrid inverter system with solar pannels, battery storage , emergency circuits and sockets so that I can run off my batteries in the event of a power cut. I have a Zappi charger and an electric car. In my humble opinion and as I say I am no solar expert the best configuration is AC coupled. You can put CT clamps an the mains tails and that enables monitoring and fine control of the batteries charging discharging and charging of an electric car with solar divert using the Zappi. Having said that solar divert can still lead to excess solar less than 1.4kW being dumped to the grid. Essentially being wasted the best option in my humble opinion is using ct clamps on a AC coupled hybrid inverter system an eco + to maximise your own personal usage of solar and minimise grid exporting . A house earthing rod is required so that your house is independent of the grid earth so that in the event of a power cut you can use your own earth to get power out of the batteries Re optimisers if you have significant shading issues there maybe a benefit, however, pannels have an operating lifetime of circa 20 + years. Optimisers may fail after 5 years needing an expensive scaffolding deployment to replace a dodgy optimiser does rhe efficiency cover the cost of the scaffolding Moot point
Yeah, I like the ability of an AC coupled system to give you greater monitoring capabilities. But then the DC coupled systems have other advantages. There always seems to be a compromise! Still, I'm just looking forward to having the solar panels and battery storage, whatever that system ends up looking like.
This may be too expensive but I installed Solarege with optimisers on a E/W install with 2 x Tesla batteries with full offgrid back up. The advantage is that you can then go on the Octopus Tesla Tariff and buy AND sell at around 24.5p/kw/h 24/7. Thus you can put only one 13.5KW battery in and its note a concern if you are pulling from the grid or battery (other than conversation losses) Also if you have an E/W install, based on your graphic, you should also be able to install a few panels South. Remember on the 6kw solaredge invertor, you can over install upto 12KW of panels.
I did briefly consider the Tesla power wall, but ultimately decided against it for various reasons. I did like the off-grid backup functionality they offer though, it does seem to be streets ahead of any other system. Adding a few South facing panels is something I'm keeping in reserve for possible future expansion, but for now the E/W array should do us nicely.
I believe the solaredge backup is only available on a 3Ph system. Without the opitimsers, when you have a little shadow on one panel, the whole string will default to that lower panel level, it could therefore have a bigger impact than you think. One other thing is that in the peak of summer both the east and west roofs will be generating so you may reach say 6.5kw/h rates. I assume you are limiting your export to 3.68kw or are you doing a G99 application?. If you are limiting to 3.68kw and your inverter can produce 6kw, the advantage of the solaredge system is that if you are only consuming 1.5kw/h in peak summer, the 5kw extra (including the 0.5kw clipping amount that is not being considered) will be diverted straight to the batteries.
We really do have zero shadowing during 95% of the day, so I'm still undecided about the benefit of optimisers. But I can certainly see how having the monitoring functionality they give you would be super helpful, so that's something to consider too. I did actually calculate what the peak output of the E/W array would be and it came out to about 5.3 kW. We've already got DNO approval for 6 kW, so we're good to go, I believe. I do like that clipping charging mode for the SolarEdge system, but I think in reality it wouldn't help us much, although I may be wrong. I suspect whichever system we end up with we'll be happy with it overall, but also annoyed by the things we had to compromises on, as there are compromises with all of them unfortunately.
We use two inverters for each of the two givenergy 10kwh batteries. This gives you 6kw charge and discharge capacity.
Yup, that's an option, for sure. I think I'm going to go for one battery initially and see how we get on. If I think the extra charge/discharge rate is worth it I'll certainly consider adding a second inverter if we get a second battery down the line.
@@TimAndKatsGreenWalk I have givenergy 5kw gen1 and 10x410w panels installed 22.10, works fine. I saw in peak 3800w on array so not bad like for October
@@TimAndKatsGreenWalk The benefit of installing a 2nd inverter and battery at a later date is it should be VAT free, as the inverter is PV kit. Just be careful getting a 5kW and wanting to add a second 3.6kW later as you would need DNO
@@MrLobsterfunkdaddy yup, good point.
You can use tigo DC optimisers on any system
If you go hybrid, the total output should be able to meet background house usage plus what the heat pump would require, plus cooking leaks etc. if you are not careful, you will still be pulling a lot for the grid, even if the sun is out. Look at your forecast demand profile through the day.
I have option two. It has been great at saving me money but as you said in the video hard to track the data correctly with the DC coupled battery. If I could go back I would have spent the extra on a Powerwall. I got the same system installed for my mother and for her it is fine she is not interested in changing her battery settings. For anyone who is considering it the settings are hidden at installer level so you have to set up as business owner in order to configure storage profiles and then assign them to the system.
As mentioned in another comment SolarEdge does have a backup option but it is not being released in the UK until 2023.
At the end of the day if the system is working and helping reduce your bills it's all good. I have a suspicion that SE will open up those settings for users to play with eventually as it does seem odd to lock them away like that. And it's good to hear they're working on the back-up option.
When you say you would have rather had a powerwall, you mean the tesla right?
One thing you didn’t consider is that a DC coupled system are more efficient because in affect you have DC to AC and an AC to DC in an AC coupled system that you don’t have in a DC coupled system.
You didn’t consider the Fox ESS hybrid system, two of these would give you what you need, I have one of these and a Zappi car charger and it doesn’t work very well when you are charging with solar but I can still use it in the summer and in the winter charge with overnight Go rates anyway and I’m talking with MyEnergy about a fix for this DC coupled problem what can happen is the charger turns on when the batteries are full and then keep charging until the batteries are empty.
In most circumstances optimizers are not much use unless you have shading in the middle of the day. The other thing I like about the Fox ESS system is they use series connected batteries, minimum capacity is 5kWh, very easy to add additional storage not so easy when you are adding more batteries to a parallel connected system as you have to worry about balancing losses in the cable runs. FYI I have a 3k8 solar array and 10kWh of batteries, unlike you I'm not going for electric heating (at the moment).
Yeah, there was a lot I didn't mention in the video, otherwise it would have been an hour long! I have heard of Fox ESS but haven't considered them for our system because they have a large footprint which I don't have room for. Otherwise they'd be a contender. I hope you manage to resolve your Zappi issues.
Hi Tim , Octopus go faster is available for 5 hours @ 8.5p per kw .
If there is no shading on the array dont worry about not having optimisers .
The givenergy 9.5 can only charge / discharge at 2.8kw .
a hybrid inverter can simultaneously feed into the AC and DC circuits , For example the 5kw givenergy hybrid inverter can push 5kw AC into the house whilst pushing 5kw into the batteries however if you are going to get a heat pump the pump can draw up to 5kw so i would suggest a hybrid inverter of 7kw
Solis 7kw fox batteries
solax 7kw solax batteries
A Zappi will work with any system using its own ct clamp
Yes, I might investigate Go Faster if it becomes necessary, but I think I've decided to go with one battery to start with and see how we go.
I was not able reach 2.8 kW. It is rated 2.6 but I saw 2.51 in peak average max is 2499w when charging and 2655 discharging. It is in utility room all the time temp there is 23-26 mean perfect like in the givenergy manual
All sounds about right to me, although I am only a newbie as well, but learning quick.
As you have an East West split on your solar, does that mean you always have half your house in shade, thus needing optimizers, or if you have each side on a separate inverter, that does it not work like that?
If you charge your battery and an EV overnight, will that stress your electrics, not sure if a constant 12kW for 4hrs could cause an issue?
My guess is the most power hungry surprise will be your microwave. I was surprised how little each ring and oven used on our cooker.
With 5kWs available, you should be able to run most things in your usual household routine.
For us, running the house in a power cut is also essential, as it happens a couple of times a month.
So the way I believe it works (but I may be wrong!) is that because the different sides of the house will consist of one string each (with 9 panels on each string) those strings operate independently even though they go into the same inverter (say with the GivEnergy hybrid inverter, which has two string inputs). If they were all connected to the same string then yes, that would be a problem for sure. Regarding the stress overnight when charging up a load of things at the same time I believe we'll be alright because we have a 100A supply, so if we add up 30A for the car (11kW), 22A for the battery (5kW), 13A for the Eddi (3kW), we get 65A total, so should have enough head room. If I want to play it save the Eddi could run at 1.5kW (6.5A), and I could charge the car at only 3.5kW (15A) since we don't do many miles. And you're absolutely right, the microwave is surprisingly power hungry, our 900W microwave consumes about 1.5kW! No idea what the other 600W is being used for. The kettle is the big killer though, at 3kW. We're going to replace it with a 2.2kW one when it fails though, so that will help a bit. 5kW should be plenty for most things, as you say.
@@TimAndKatsGreenWalk Your understanding is spot on.
@@TimAndKatsGreenWalk 30A is only 7kW for car charging. Not an issue for your calculation on headroom on the supply, but you won't get quite as much charge into the car as you've allowed for.
@@johnmckay1423 yes, we don't do many miles at all, so 3.5kW each night for 4 hrs should be plenty as it happens. But if required we could use the full 7kW as I think that would be fine.
I am looking to keep my UPS option open too, because I've replaced my lead acid batteries with 2 x Seplos Mason 10.5kWh LFP with an out limit of 200A DC, which giving me 18kWhs of useable storage. (80% helps to prolong the life of the pack) I too need to change my Inverter as a result. I have two strings coming into the house, I have to have a dual string input on the Inverter. So I am going with the Sofar HY 6000-EP Inverter. This has a 27A AC output which fall inline with the current Inverter, but can charger higher rate of a 100A DC, as opposed to 60A DC for the old Inverter. Currently on a sunny day I can get 14kWh (September) off my 4kw solar array. Mine operate without optimiser and there is little to gain from what I can see in your application to installed them. We have 2 batteries because we have a ASHP 9kw, Quin Sunamp 9kw, some Infrared panels, and 2 EV's to charge up. We to use the over night Octopus Go tariff to aid our charging use, and so far have achieve good results. In your case I would go with option 3. We have also uprated of house fuse to 80A, I don't know if you have taken this into consideration?
That's very interesting. Yes, our house already has a 100A supply so we're good on that front. As it happens I've just agreed with our installer to go for option 3 so I'll have more to say on that in future videos as and when the installation gets underway.
@@TimAndKatsGreenWalk I will look forward to that!
I’m currently having option 3 on an east west two arrays. I have shading do we are using Tigo’s for optimisation, works out extra £50 a panel remember do on installation and no VAT. For you EPS read up on the Givenergy solutions, I’m trying to go full house manual switch, waiting for a quote but looks fairly straight forward. As for EV charger Givenergy currently have one out on beta I think which would talk to their hybrid inverter. There is also talk of a diverter in the pipeline that would do hot water .
Yup, my installer has talked me through the GivEnergy EPS options and I'm thinking of doing the same as you. Good to know you can run anything you like, as long as you're careful to stay within the limit. I need to look at their charger to see how it compares with the Zappi, which is the current plan.
Hi Tim. Based on the Datasheet for Givenergy 5kw hybrid inverter, it seems the max battery charge rate is 3.3kw (same as 3.6kw inverter) so am I correct to assume that having a 5kw inverter is not going to help with fully charging 2 x 9.5kWh batteries in let’s say 4 hours? Thanks
Yes, you're correct, the charge rate is about 3.3kW for the 5kW hybrid inverter, so that becomes your limit. We're able to nearly charge our 9.5+5.2kWh batteries in the four hour overnight cheap window so you certainly wouldn't be able to charge two 9.5s. If you can get a six hour cheap window though you'd be set.
Hello Tim, I would appreciate knowing who's doing your install and how good a job they do once you have figured out your system. Definitely worth an install video as follow up in due course.
Just be careful with your ASHP , I've just had a quote that split the power consumption in three; heating mode 7944kWh/yr (SCOP 3.5 @ 50C), hot water 3082kWh/yr (SCOP 1.75 @ 50C) and Legionella cycle 7800kWh/yr (SCOP 1 @60C). So as you can see the Legionella cycle for the quoted 300l tank consumes nearly as much electricity as it does to heat the whole house.
The rep went thru' the heating benefits but skirted around the water heating and Legionella cycle, it wasn't until I got the magnifying glass over the arithmetic that I spotted this.
Needless to say I will not be purchasing an ASHP.
It looks as if the Legionella cycle was quoted to run purely on the immersion heater, and quite often. Worst case is raising 300L of water from 10 degrees to 60 degrees takes 4200 * 300 * (60 - 10) / 3600000 = 17.5kWh, ignoring cylinder losses which might be 1 or so kWh. Doing this every day would take 6400kWh.
More modern heat pumps (Vaillant Arotherm Plus, Samsung HTLN) are able to reach 60 degrees with a COP of around 3, and once a week is sufficient, so this would use about 300kWh. Note that holding a lower tank temperature for a longer period of time (a few hours) is also effective.
Yes, absolutely, I'll be covering the install in a future video for sure. As it happens we're getting an air-to-air heat pump system fitted soon (also to be covered in a future video) so our hot water will be provided by the Eddi solar diverter device instead of from a heat pump. It's worth checking out the Heat Geek channel for more ASHP advice if you've not already. I'm surprised by your legionella cycle values, I'd have though most ASHP could do that at a decent SCOP. I don't have first hand experience of that though.
@@asabriggs6426 Thanks for your reply it is much appreciated. Legionella cycle is immersion only @60C for 30mins each week. I have seen on other vids that 60C for 1 minute each week should be enough. But the installation quote allowing for over kill (perhaps to avoid any hint of a risk to avoid litigation) is off putting.👍👍
@@TimAndKatsGreenWalk Thanks Tim. I've subscribed to the HG channel and there is much wisdom on offer.
Immersion quoted for Legionella cycle to 60C rather than using the ASHP to heat to 60C. Odd.
@@davidreece1642 yeah, that is odd.
A lot of solar PV reciewers such as Gary does Solar etc, are now saying optimisers and micro inverters are not required on newer PV due to the inbuilt diodes effectively making the optimisers \ micro inverters obsolete. The diodes manage the panels so any shading issues doesnt drag down the whole string to the output of the affected panel.
Yup, I love Gary's videos. I've decided not to use optimisers now since we get no shading anyway.
Gereat video, Tim.
Option 3: The GE 5kW Hybrid will only alow you to charge at 3.6 kW (not 4.7), so your max capacity in four hours would be 14.4 kW.
Out of interest, why can't you use optimisers on Option 3?
Yes, I discovered this about the 5 kW hybrid inverter shortly after I published this video! I knew I would get something wrong, so this is why I asked for corrections, which I'm very thankful for. I've also been told that optimiser from Tigo would work with option 3 but I think that actually I don't really need them in any case since we get no shading really.
Gen1 is even less. It is max 2.5kw (real world data)
@@theundertaker8273 I don't think that the Gen 2 is much better. We've just had a hybrid 5kW Gen 2 installed and max charge and discharge in the settings is 2600W. Last night I set to charge on cheap GO and max charge rate was 2456W.
I had made a similar misunderstanding to Tim when I costed up a 2nd 9.5 battery.
If you are planning on using cheap rate charging to charge and second battery, I would seriously consider installing 2x 3.6kW Hybrid inverters with a battery each. This means you can charge both batteries in a 4 hour window. I'm not sure how much better this would be for the PV charging of the battery, but if you have a split east west system this could make a lot of sense. The payback on 1x5wK hybrid and 2x9.5 doesn't add up by my calcs. A lot of DNOs let you have 8kW of inverter limited to 6kW. 2x3.6 hybrid is obviously within this.
@@MrLobsterfunkdaddy thanks for info. I went to gen1 because my installer was very shitty they even lied me with warranty thankfully I have offer on text and paper with 12years warranty for both but just 5 in givenergy portal. Thankfully I have 8.2 100% battery because older one was 80% and was smaller. 100% 8.2 dod is real 10.5 old was was real 8.2 -20%. I'm happy now just opened case with solicitors and with my installer about warranty. But overall after 1 month of battle with installer all working just warranty left but will be easy to win.
@@MrLobsterfunkdaddy could you check setting for inverter on the portal? There is a slider and maybe default cap I 2600 but you can extend this to 3600?
You're assuming cheap night time electricity is hear to stay! Who knows, probably, maybe? One thing is for sure it will also rise. Having a heating system providing efficiencies of 3/4/5 to 1 will limit your risk of a cheap tariff being removed. I'm not saying dash out and purchase a heat pump either. I'm also wondering what to replace my old gas boiler with that will heat my house efficiently. I have Solar and battery storage, a Sonnen unit which I had to wait more than 18 months for a repair on. If I relied on this for heating we would have been cold for 2 winters. Which ever one you choose consider asking what is the after sale service like. I would not recommend Sonnen.
Yes, true, although I'm pretty confident cheap overnight tariffs in one form or another are likely to remain available for a while. If anything I expect they'll become more common. We'll be getting a heat pump system installed within the next few weeks which is 400% efficient so we'll be good to go to ditch the gas boiler this winter with or without the batteries. That's the plan anyway! We'll cover that in a future video.
Great Video! I have an Air-Source Heat Pump and will hopefully soon get my solar and battery. Of course I don't know the size of your house and insulation status, but 15 kwH per day for heating in winter sounds too good to be true. Installers tend to mislead people about the actual usage of these pumps so I am really interested to see an update of this video once you have the pump, to see if your batteries cover all usage!
Take a look at the channel, there are loads more videos since this one covering the heat pump 😉
And it is too good to be true. 15kW for a heat pump over 24 hours in winter is unrealistic at best. Heat pumps will run in anti freeze mode for hours overnight. The theoretical figure is 15kW, with anti freeze running you can probably add another 10kW to your calculations. This from a 100% electric home, zero gas, A rated EPC, whole house. All underfloor except 2 x towel rails in bathrooms. 33.7kW GivEnergy battery storage, 6kW PV and still buy from grid in the winter. 😕
I have just had a 6.2kwp system installed will solaredge inverter and battery. I haven’t got the backup system but I do believe that it is possible with solaredge. On the subject of optimisers, if it was me in your position I would get the system which allows them. When you do get shading it would essentially kill the power from that whole string. Your installer would be best placed to give you advice though.
Break even isn’t good enough. There needs to be a significant saving to off-set the risk of costs falling in the medium term.
Well, it depends what your properties are. For some cost is the most important thing but for others not as much. There are other benefits beyond the cost savings that might make it worthwhile.
Personally I'd recommend a Victron inverter with pylontech batteries. They're modular, so you can add more at a later date if needed. You're very good at maths and spreadsheets, so I'm sure you've already considered this, but if you're getting solar installed, making sure you can supply the whole house electricity from batteries for the few days of the year where you have no solar at all and it's very cold is likely not the most efficient use of your money in terms of return on investment.
I did some somewhat crude calculations looking at electrical demand each day vs number of pylontech 3.5kWh batteries needed to meet that demand:
4 batteries got me to something like 50% of days
5 got me to 80%
6 to 95%
7 to 98%
But to get to 100% took 12 batteries.
So there was definitely diminishing returns. and that 5% would never have paid for itself considering it took twice as many batteries to meet that demand.
(This was batteries alone, no solar. It would have been a lot more complicated to calculate them combined.)
Yes, exactly, my latest spreadsheet answers this very question (it now includes batteries and solar so keep your eye out for the next spreadsheet video). I decided it was not worth going as high as 19 kWh but going to 14 kWh was just about cost effective. With solar, batteries, and heat pump heating it should all pay back in about 12 years, amazingly (assuming current prices). Although there are lots of simplifications and assumption in the calculation it's still more reliable than sticking your finger in the air!
SolarEdge optimised panels are fantastic, if you need them. I worry that your installer doesn't seem to be able to tell you things like "can I use this system as a backup in a power cut" - do check they are MCS accredited, as also you'll need that if you want to be paid for export. I also think both your battery sizes are too small if you want 20kwh usable a day (depth of discharge means you'll get less actual power in or out) and also you are betting a lot of money on tariffs like Octopus Go being around for 10 years +.
Yeah, I didn't mention depth of discharge as I didn't feel that it was super important to the overall point of the video, but I take your point (I do know what it means ;)) The GivEnergy 9.5 kWh state the DoD is 100% while the SolarEdge ones claim 9.7 kWh is available out of the 10 kWh stated capacity, so it's not too far off. The 20 kWh use per day figure was pretty approximate in any case, it was just a conveniently round number for the purposes of illustration.
If anything I bet that time of day tariffs will become even more common over the next decade, but you're right, that is a risk. It's one I believe is acceptable though.
Our installer is super busy right now (as they all are) so I'm not pestering them with every question I have right now, but in due course, once we're at the top of their list, we'll be having a thorough discussion about all of the options. In the mean time I'm doing my own research and asking strangers on the internet to help fill in the missing pieces of my understanding. So once we do get to have that discussion I will be as informed as I can be so that I ask all the relevant questions and end up with the best system for us.
Interesting video. I have a Givenergy 3.6 hybrid inverter as well as a Zappi and Havi controller. The Zappi is connected to a outside IP68 CU so the inverter cannot see it. A CT clap in the meter box tells the Myenergy software when we are exporting to the grid and takes that charge as needed. The GivEnergy system software says this is all export but the combination of these apps plus Octopus Energy app, gives me the complete data picture. Unlike you I have done this in stages which makes this a tad more challenging especially as I am now looking at removing the combi gas boiler and going all electric. The details matter and it is certainly far from easy with so many variables so our shared experiences hopefully save others from making mistakes. I have to say I have been very impressed with GivEnergy although I don't have experience of other systems as a reference. I was super impressed that a software update I suggested was implemented just 3 months later, so they clearly listen to feedback and their software both on your phone and PC is excellent.
That's great, thanks for explaining your system. It's good to know that you're impressed with GivEnergy. That's one thing I'm particularly looking forward to once we've got our system, looking at all the data etc. Our plan is to get rid of our gas boiler within the next couple of years and I think we're on track for that so far. It might actually happen next year some time with any luck. We'll be covering it all on the channel so hopefully folks will be able to decide if it's something they could do too, or not.
@@TimAndKatsGreenWalk Thanks...yes I'm on the same journey looking at heat pumps v air con and waiting on quotes on both to start the assessment. And then looking at the power implications ref our existing solar/battery system as I have space for 4 more panels which could be useful not least because it will mean zero VAT on the extra batteries that I will no doubt need. Anyway like you will be sharing my journey!
@@doingourbit8551 ah, of course! I thought I recognised your channel name. I'm sure I've seen some of your videos before but I've just made sure to subscribe too.
Yes, I just checked and I had watched some one of your videos before. Great stuff!
7kw exceeds the max dc input of givenergy 5kw hybrid inverter listed on the datasheet. This may or may not be a concern. Also the max current input is quite low on this inverter. We couldn't source any panels that would meet the listed max current rating. All this info is on the inverter datasheet.
Yes, I forgot to mention the limit of 6.5 kW DC input for the 5 kW hybrid inverter in the video. I believe that's ok though as the East/West split means the max power from the array is probably about 5.3 kW. I'd not considered the max current issue though, so thanks for bringing that to my attention. I'm going to look into that a bit more.
Agreed with regard to East West and performance....one thing I wasn't sure about was invalidating the warranty...I guess givenergy would advise on this?
Hi Tim. Regarding the optimisers. If you have an East and West panels as the sun moves around wont it cause shading issues on each set of panels at one point or another in a way that optimisers will be of some benefit as they are likely to prolong the generation period of the panels as they slowly become shaded?
The inverter has two string inputs so each side is separate and won't affect the other when shaded. It works pretty well without optimisers.
AC coupled battery storage is a much better option imo. Firstly you can combine both the solar generation and the battery to output more power than a DC coupled sytem where you are restricted by the max AC discharge rate of the the inverter. Basically you get rid of that bottleneck in the system. Secondly an AC coupled battery is much more flexible in installation and when setting up with EV charge points, as you 'can't see' the DC coupled battery which is hidden behind the hybrid inverter. Thirdly the conversion losses compared to DC coupled system is nothing to lose sleep over, it's negligible. Cheers.
They both have pros and cons. Depends what your preferences are, really.
Interesting video.
I have just selected and am having installed tomorrow the GivEnergy 9.5 battery to compliment an existing solar array. I am also putting a second new array on the back of the house.
A couple of thoughts on the issues you saw.
Firstly - you could always add a second GivEnergy ac inverter into the mix to give you 6kw charge and discharge.
(My plan is to add a second battery into the mix once I have seen how the second solar array performs - maybe adding a second ac inverter, maybe just daisy chaining)
Second thought is have you considered going down the micro inverter route for you arrays. My second array is going to be an enphase microinverter solution. Shading issues don’t exist, ultimate flexibility and maximum efficiency (and lots of panel level data).
In my last house we had a 7kW array with Enphase microinverters but no batteries. The data detail was great, but since the output of the array was AC, if we added batteries there would be a conversion loss to back to DC to charge the batteries, yes?
Yes, I did wonder about a second inverter. Since this video I've decided to go with just one battery for now and then see how it goes. If I decide I do need a second battery after all I'll certainly consider the second inverter as an option at that stage. I hadn't considered micro inverters but it's an interesting option. Probably a bit late now given where we are with our install coming up soon, but if I ever get an additional array like you I'll have a think about whether that would be a good option or not.
Great video, thank you. I think battery wont charge same rate last 20 %.
Yes, you're probably right. I've got a bit more to figure out for sure, so thanks for pointing that out, I'll factor that in to my final decision.
Check out the Fronius GEN24 Primo and the BYD battery modules.
Great Video
I have two Electric cars and a ZAPPI charger
Looking at option 3 mysel, butt is it compatible with the ZAPPI, ?
Two 9.5 is what I want also with a 5 kW inverter
Yes, we ultimately went with option 3, although with a 9.5 and 5.2 kWh battery as it turns out the charge rate is only 3.6 kW, not the 4.7 I said in the video (I've got loads more videos showing the install and the monthly stats etc. so you can see how it's been performing). You can set up the zappi to have a small export margin (say 100W) so that it can still work with the batteries by waiting until the batteries are full before sending excess solar to your car. Myenergi have a tips section on their website giving the details, I believe.
Hello there, finding your videos very informative . My question to you would be: other than cost, why have you not considered the Solar Edge AC coupled 10kWh storage Battery, and have you considered Mains power failure back-up?
The SE inverters are by nature hybrid when connected to their own batteries, so AC coupling would be unnecessary really. Unless you wanted to add two SE inverters which would add to the cost. I mention the backup functionality under the pros and cons lists, at the moment SE don't support it but I believe they are working on it.
When, oh when, will Sodium-Ion batteries be available to punters in the UK? This would be game-changer. All these rock-stars like Faradion et al tell us how they're going into production, revolutionizing grid storage and heavy vehicles, soon they'll be in EVs, but ..
"Please can I have one for my home microgrid?" "Uh, wha.. wot dat?"
Yeah, that'll be a great addition to the market.
Why can’t you use optimisers with GivEnergy DC charging? Surely they just bypass individual cells? Or do they have to communicate? What is the best solution then for 3 phases - as I am limited to 4kw on each phase
Solar Edge optimisers require a Solar Edge inverter to work (it's the inverter that controls the optimisers), so you couldn't connect your panels directly to a GivEnergy hybrid inverter. However there are other types of optimisers that might work with GivEnergy inverters, such as Tigo (although I don't know much about them). There are now a handful of three phase systems available and in fact GivEnergy have recently released their own three phase system. That might be worth a look.
Fantastic video I'm installing a hybrid inverter with 13.5kw of pylontech batteries with no solar at this point. I'm interested to know how you plan to heat the house on batteries only thank you
Well, it turns out I'd need more than two batteries to cover all our heating needs for the coldest days. I've just finished editing a follow-up video showing the calculations so hopefully that'll be up in the next couple of days.
@@TimAndKatsGreenWalk fantastic look forward to seeing it
Another informative video, have you posted anything regarding G98/G99/G100 DNO applications (Costs/time/pros & cons)? Does your 5kW inverter also result in supporting higher house loads and reduce probability of needing grid power (thinking of your kettle and toaster example)? Thanks 👍🏼
No, I've not done a video about DNO applications. I don't know much about the process really, since my installer handled that. The 5 kW inverter is so far proving pretty good at keeping grid use very low but you only get the full 5 kW when you've got some solar to support the 3.6 kW you can get from the battery. In the winter we won't get the full 5 kW very often I suspect!
Thanks for the quick reply. So if battery is full and no house load your max grid export is 5kW (assuming you are generating that)? I think one of the DNO application options limits the export but I’m still researching that.
@@Stickneytube yup, G98 limits you to 3.68 kW, while G99 goes higher (although there can still be a limit imposed by the DNO). Your inverter is what determines the maximum export rates so yes, I can export 5 kW at the most. G98 is usually automatically granted, which is why a lot of standard installs keep below the 3.68 kW limit to ensure a quick and easy DNO application. If you have enough roof space for more than that though I'd go for as much as you can and put in for G99 application. It'll take longer to go through and isn't guaranteed but the extra capacity will be worth it, I reckon. You can always try ringing your DNO before deciding to see how likely they are to grant G99 approval and at what limit.
Charging overnight will pull your average kwh unit rate down. We average 8pkwh ourselves. Our setup is slightly different, we have 2 solaredge se5000 and a pair of Lux 3.6 AC coupled inverters. This allows fully charging the batteries overnight in the four hour period. The setup means on a bright sunny day we can achieve over 10kw of discharge (solar+ac inverters). The Lux provides a 16 amp EPS system which work well, however if there is a power cut we loose the solar. Anything option is victron setup with a g100 rating. This allows completely off grid but victron is not cheap. Optimisers are down to shading, we have a bit of shading on our setup which helps and this shading is down to the seasons and the height of the sun. I can show you a couple figures etc on the setup. Ours is not the cheapest setup.
That sounds like a good setup. I'm hoping we'll manage to achieve almost all of what we want but time will tell.
Great Video. Very interesting discussion. Have you installed the system? If yes what is the final solution?
Not yet, it should be coming in the next month, hopefully. I went with option 3.
@@TimAndKatsGreenWalk thank you. Are you still going for two batteries or just one.
@@DahouiM well, sort of 1.5. I'm going for one 9.5 kWh plus one 5.2 kWh battery. See my recent video about Cosy vs Go tariffs for the reason why.
@@TimAndKatsGreenWalk thank. I’ll watch it this evening
I have pylontech and from experience they are very good. You can start small and add if you change your mind. Also very cost effective. If you are still flexible I recommend them
I placed my order today for a 4.6kw array with Givenergy 3.6kw Gen 2 hybrid inverter and 9.5kwh battery 🔋
Excellent.
Hey, Tim what did you go for in the end? I am having same decision problems.
Option 3. Although I've gone for one 9.5 kWh and one 5.2 kWh battery for reasons I'll explain in the next video!
From your bio, I see you're on the edge of the Cotswolds. Would you mind sharing the company you're using for your solar installation?
Sure thing. B-line project services. That should pop up if you search for it. They're pretty busy like all the others though!
@@TimAndKatsGreenWalk Thanks. My Dad's just outside Cheltenham and he's been looking for an installer without much success.
Have you considered having a duplex system. 2x Givenergy AC inverters each with their own battery. Charge at 6Kw. bit more expensive but ...
Yes, that's something I'm considering for the future but I've now decided to start with one battery and see how it goes. If I decide to add a second battery in the future this is definitely something I'll consider.
The 10kWh StorEdge battery and HD Wave inverter from SolarEdge cannot work off grid. New single phase models of battery and inverter will be released by SolarEdge next year with this capability. A three phase system already exists.
People always say that they don't need Power Optimizers as they have no shading, but what is shading? Soiling, snow, clouds, birds on modules, trees (they grow) chimneys, aerials, telephone cables that are in front of the modules. What about the other benefits? You do need Power Optimizers due to module mismatch, as each module will differ +/- 3% regardless of azimuth or tilt. Safety, with the S series Power Optimizers, they have a thermal sensor that can detect the rise in tempertature and shut the inverter down to 1 volt per Power Optimizer (SafeDC), with AFCI, you can also stop an Arc at module level, and reduce the risk of fire. What about the monitoring, you want to see what each module is doing, you would'nt drive a car without a speedo, or fuel gauge. Maintenance, being about to power your inverter down, and removing the risk of electric shock to anyone working on the roof or near the modules. You can't do that with out SolarEdge Power Optimizers.
There are a few studies now suggesting optimisers are only marginally beneficial in most cases, and the added cost might not be worth it 🤷
@@TimAndKatsGreenWalk 2% added generation as you have a MPPT at each module. Over 25 years, that will cover the cost. What about Safety, and the monitoring side? How will you know if you module is underperforming or damaged? I have a difference of 27.08 kWh between my best and lowest performing module out of nine on a south facing system, in 17 months of production. A total of 132.45 kWh that i would have missed out on, if I had gone for a traditional one MPPT inverter.
A very interesting video thank you. At the moment I am still in the process of trying to source a supplier for a solar system. However if I have interpreted your video correctly you aim to meet all of your electrical power needs by charging your battery at night using cheaper electricity. Using this model do you think there would be sufficient savings to negate the need for having solar panels installed and just having a battery system? Although I recognise that this would then attract a VAT charge. Many thanks.
Good question. I am working on video covering a thorough calculation for the winter heating savings which will hopefully be ready in the next couple of weeks. That will be ignoring the summer use though. This model is primarily aimed at covering the heating requirements during the winter when there isn't sufficient solar to cover all of the electrical needs, but during the summer that's when you gain the most benefit from pairing the solar panels to the battery. Having said that you can do a quick and dirty calculation based on your average daily electricity use and then just multiply that by the difference in price between a standard flat electricity tariff and the off-peak rate to get the total savings over the year. For us that would be ~5 kWh * 365 days * (34p - 7.5p) = £484 per yr. If we got a 5 kWh battery we could cover most of our needs by charging up overnight and using that charge during the day, and it'd break even in about 10 yrs, which is the typical lifetime of the battery. This wouldn't cover heating though. In the summer (probably Mar to Oct) the solar would charge the batteries so the savings would be higher as you're not charging overnight, and you also have the opportunity to get the smart export guarantee for any excess solar you generate, so I reckon you're still better off getting solar as well. But if you can only get batteries it's worth considering, for sure.
@@TimAndKatsGreenWalk Have you chaps/chapesses seen the channel 'Gary Does Solar'? He goes into exactly this subject in depth and has created a superb spreadsheet that allows you to input your conditions to compare basic electricity with PV/battery and just battery. He links his spreadsheet so you can play with it for free. The video is: ua-cam.com/video/FvjuJQZRrvA/v-deo.html
I’m not an expert but have done research like you. I have solar edge dc.
It’s very easy to monitor and works well with Zappi in my experience.
Re optimisers, I understand that it’s not just about shading. It’s also relevant if a single panel in a string fails or underperforms. I can see from the monitoring app that my panels facing in the same direction differ in their production by up to 10%.
I think Octopus is brilliant but I wonder how sustainable their Go tariffs i.e. are they profitable for them. At 7.5p, do they even cover transmission costs?
I’ve been using the Octopus Agile tariff (not available with Go) to benefit from up to 80p per kWh at certain times over the summer. I’ve been discharging my battery fully between 5pm and 7pm each day.
Cost wise, I’ve seen 9.5kw GivEnergy quotes as little as £3k as part of a solar package. My Solar Edge was nearer £8k. May be not the best choice.
Good to know the Zappi works well with DC coupled systems. For the optimisers I've seen studies that show very little difference in overall generation for short strings (7 panels or so) when there's on shading, so I'm still undecided. I think the reason it makes not much difference is that in low light a string with no optimisers will start generating earlier so you gain a little benefit there which might offset any benefit from the optimisers when the light is stronger. Anyway, whatever the reason we're in that situation where it's unclear whether they'd have a material benefit to us, so I'm not currently considering them as essential and will go without if other factors are more important (everything is a compromise!). For the overnight tariffs, I expect they'll be around for a long time, and get more popular, even if the actual numbers change. It's certainly something to keep an eye on though. Amazing that you were able to get 80p/kWh at peak times.
Our Octopus payment for solar surplus is now up to 15p per kWh. They are one of the most financially secure energy retailers so it must make sense (they are charging 34p per kWh for grid-sourced electricity)
Have you taken account of the 6kWh that you can deduct from the gas consumption and switch to your immersion heater (this would only drop the ASHP requirement by 1.5kWh due to its 400% efficiency).
ALSO your ASHP could also be set to run during the 4hrs night time rates.
Yes, there are some subtleties I didn't cover as it was already a long video! But yes, running the heat pump overnight is in fact something we're already doing and I accounted for the hot water gas usage in the heating calcs.
Hello, great info and details. Question, I have been offered sunsynk 3.68 inverter and a sunsynk 5.32 battery with longi panels 12. Any views on the sunsynk against Givenergy equivalent please. Much appreciated for any comments. Thank you
The specs for the 3.68 kW Sunsynk inverter are similar to the GivEnergy 3.6 kW hybrid inverter so not much to choose between them. Ditto with the 5 kWh batteries. The main difference comes with the 5 kW inverters where the Sunsynk one beats the GivEnergy one on the battery charge and discharge rates. So for you it'll come down to price and control features. I don't know much about the Sunsynk controls but from what I've seen the app support is better for GivEnergy, so that might be a consideration for you. I'd recommend tracking down the datasheets for the two different systems and comparing them to confirm what I've said (in case I've got anything wrong). But hopefully that helps a bit.
Considering a second battery but I can’t make it make financial sense yet. Woudl be mainly for heating which means winter which means not much solar - so its off peak 7.5p vs 10p gas. Even with 400% COP the savings aren’t that high for that portion - Maybe £250 for gas for 6 months of heating vs £50 optimistically for a heat pump? I’ll definiltely add it if we have the spare money but it’ll be for ‘get off gas’ reasons rather than ‘saving money’ reasons
Yes, exactly, I'm doing this as much to try and get off gas as to save money. Having said that I've just finished editing a video showing a much more detailed calculation so hopefully that'll be up in the next day or two. It turns out it's not as clear cut as I suggested in this video!
If you need optismers Solaredge is probably the one to go with but you can use tigo optimsers though I've heard they aren't great at the commissioning stage so installers don't mention them. I would probably look at Pylontech batteries as the cost per kwh is better than both givenergy and Solaredge, linked with a victron mulitplus 2 will give good data and the pylontech batteries are modular so can be added to if you need more.
Yeah, Pylontech batteries would be an option except for the fact that they lie flat and I don't really have the space available for them. That's why I'm considering one of the vertical systems instead.
PylonTech Force L1 or L2, modular again. L1 = short and fat, L2=tall and slim. I think SolarEdge optimisers have to have one on every panel (or min of 6?), whereas Tigo, Enphase, Huawei can have individual optimiser on selected shade problem panels. Tigo are ~£50.
Do you need an enclosed space to install storage battery? Sorry, if it is a stupid question...
Some can be installed outside, although a shelter is recommended to keep the elements off. They do need a bit of space around them for ventilation too, so a small cupboard is not ideal. Mine is installed in our garage with some space around it. Some people install them in the hallway.
@@TimAndKatsGreenWalk Thanks a lot. That’s another thing I need to consider.
Solaredge DC-coupled + Eddi user here - all fine, it's just a case a configuring the Eddi correctly.
That's good to know, thanks.
So what about Puredrive 2 vs Givenergy? Which is better?
You'll have to do your own research, I'm afraid, I can't cover every system, there are loads!
I noted that Soalx X1 -Hybrid G4, 6kw inveter has 6kw charge/discharge rate, please correct me. Thanks
Are you asking a question or making a statement? I don't really understand what you're saying, sorry.
Sorry Tim, I mean Soalx X1 -Hybrid G4, 6kw inveter has 6kw charge/discharge rate. it is good option.
What are the disadvantages with pylontech ? From what I know they are top notch batteries and they are modular .. £8k for 4 us5000 and then you când add to them ...
It depends what you're after. They're not right for me but I'm sure they'd be great for someone else's needs.
What’s your guesstimate as to how much the solar panels will produce over winter (good days and bad days)?
That's a good question, and as it happens I just published a new video that includes just that: ua-cam.com/video/g0KbYqfCq1w/v-deo.html. Some days will be zero, and at most they'll probably hit 5-6 kWh in late Dec.
Is thw ZAPPI char compatible with the givenergy system
I am specing 2 9.5 using octopus GO like you
You asked this before and I replied to your previous question. The zappi will work alongside any battery system, yes, just look on their website for how to set it up properly to work with a battery.
What did you go for in the end?
Take a look at the other videos on my channel, in particular the playlist about our solar and battery system, to see all the details. In short, option 3 but a bit less battery capacity.
Use tigo optimisers only on the ones that get shade.
I hadn't realised Tigo optimiser could work with any system so this is good to know, thanks!
@@TimAndKatsGreenWalkNp. also you can add them to a gateway and monitor them individually with cloud connect
@@zamankhan4444 yup, very handy.
I’ll add my thoughts although I see this video is 6 months old so you’ve probably already chosen your solution.
I have a 4kW existing FIT array and had a 10.4kW array (East and West facing) with 2x GivEnergy hybrid generation 1 5kW inverters, a 9.5 and a 5.2 battery, one on each inverter. Similar but larger than your option 3.
I needed two inverters due to the number of panels, and it looked like your 3.6+3.6 arrays are actually slightly larger than a single inverter capacity. Worth noting that GE don’t officially support the twin-inverter setup I have although it does generally work ok.
I think you have the overnight charge rate of option 3 wrong. My gen 1 inverter can only charge at 2.6kW, the gen 2 is better but it’s only 3.3kW. With multiple inverters each with their own battery you can get higher throughput with parallel charging.
Agree batteries are important but the payback for 2nd and 3rd batteries is poor, so even though we have an ASHP we’ve not got more batteries.
Do maximise the panels on your roof as the first option, cheaper add more when the scaffolding is up.
Yup, the system is all in place now. Take a look at my recent tour video for the final arrangement. We've also had the ashp in place all winter (there are many videos about that too) and everything is working great. We're able to charge at 3.6 kW with our gen 2 hybrid inverter (the new spec sheet says 3.3 as you mentioned, but ours definitely supports 3.6 so not sure what's up with that).
Im looking at Growat, Give and SolarEdge, is there any reason you haven't looked at Growatt? Many thanks
That's a good question and the answer is simple, I'd not heard of them before you mentioned them! They look interesting though. My installer is familiar with GivEnergy and SolarEdge so those were the options we discussed. I'll keep my eye on Growatt for future reference though, thanks for brining them to my attention.
@@TimAndKatsGreenWalk They seem pretty big but the app seems the least UX friendly
Get voltacon hybrid inverter, pylontech batterys were you can have 16 x 5kw batts on one data line x 4 on a hub....
Too late for that, I'm afraid.
Switch to Intelligent Octopus for 6 hours (6x3=18)? or go faster 5 hours (but slightly higher off peak rate)? I’m going single Givenergy 9.5 but already have solar so will be effectively forced to go AC coupled.
Yes, that's an option I'm looking into. At present we can't use Intelligent due to not having a compatible car or charger but it might be viable in the future if they add more cars/chargers to their list so I'm keeping an eye on it.
@@TimAndKatsGreenWalk i was on intelligent but it can be a pain for batteries - they can drain during ‘extended’ hours into a car if it’s charging. So I’m trying to switch to go faster ending at 06:30 to help with early morning heating without needing battery for that
@@MrKlawUK ah, interesting, that's worth knowing, thank you.
Great video and all very interesting. It is hard to gain concrete answers. I have the same idea as you except for not using solar panels. I am on GO and I thought a Givenergy 2 x 9.5kw on the 5kw Hybrid inverter would offer about 4.6kw output x 4 hours = just under 19kw but on speaking to Givenergy they told me that of the 5kw output 1.6kw is Solar only (hence Hybrid) leaving only app 3.4 kw to charge in 4 hours = 13.6kw of charge. I then said could I use 1 x 3kw AC for each 9.5 battery pack and they said; only if they are on separate phases as there is some kind of conflict with information
I did ask would it work if each battery fed separate consumer units, answer no, so this brings into question if your neighbour had the same system on the same phase could this be an issue and I was told it would be an interesting point
At the moment the option may be 1x 9.5 & 1 x 5.2 = 14.7 and the Hybrid 3.6 output x 4 hrs = 14.4 fully charged. My daily normal kWh is app 20kw so either I am not at present able to fully fund peak use or wait till they have got over the issues
What do you or anyone else think?
Yes, all good points. I discovered after making this video that the hybrid inverter limits the charge/discharge rate of the batteries to 3.6 kW, as you found out too, so came to the same conclusion that it's not possible to charge up two 9.5 kWh batteries in 4 hrs after all. I've also heard about the complications involved with two inverters on one phase so that seemed like a nonstarter as well. It's all very complicated! I'm now looking into the new libbi battery by myenergi, which has a higher charge rate of 4.6 kW (see my latest video), which would give 18.4 kWh of capacity after 4 hrs, so that might be worth looking into. The libbi supports up to 18.4 kWh of usable capacity (in blocks of 4.6) so that could be a good option for you perhaps (although possibly a bit more expensive than the GivEnergy system).
@@TimAndKatsGreenWalk Thank you for responding. I am carrying out further investigation and will come back yo you
just to add an option 3 into the mix, you could have 2 give energy AC chargers, which gives you your requirements, and additionally you remove on option 2 & option 3 the single point of failure which the hybrid inverters, and more expandability on the batterys later should you need to store more, and instead of optimisers, you could go with micro inverters
Yes, two inverters is something I've considered and I'll mention that to our installer. I'll see what they say. Although as it happens I may be leaning back towards having only one battery, but more on that in a future video...
There is a big problem with dual inverter setups right now and Givenergy plan to launch an additional piece of hardware to better manage this setup.
Also I think 3kw is max, more likely 2.8/2.9kw due to heat loss & conversion losses.
@@RH-xj8hm what is the big problem?
@@andypryke6750
This is part of a reply to a discussion thread on Facebook and is a response from a giv energy employee.
“Dual AC coupled systems for the most part work, but there are known issues with this set-up that we’re trying to iron out right now. One system may work harder than the other, and therefore the two can become unbalanced. There is also a bug with the total calculations for the amount generated in a day, or the amount of energy used in a day. These things won’t stop the system from performing, and you’ll still get the better charge and discharge settings, but it’s important for customers to be aware of these issues going in, as we do not currently have a time frame as to when these bugs will be addressed.”….
You could look at using Intelligent tariff from Octopus which gives you 6 hours of off peak.
Unfortunately that tariff only works with certain cars and chargers, which we don't have, but they might add more in time so I'm keeping my eye on it.
Have you considered the Intelligent Octopus tariff, same price as Go but gives you 6 hrs at cheap rate. The tradeoff is that you say by when you want your car charged and they control the actual timing of the charging. 3x6 is 18 kwh.
Also, LFP is much better for deep cycle applications like a home battery. So id go AC coupled GivEnergy.
Unfortunately the Intelligent Octopus tariff is only available for certain models of EV, which doesn't include the one we're getting. But otherwise that would be worth pursuing. I'll be keeping my eye on the list of supported EVs though, in case they add our one.
@@TimAndKatsGreenWalk For the Intelligent Octopus tariff, isn't it supported EV's OR having an Ohme Home Pro EV Car Charger with any compatible make of car that can use an Ohme, which is what I thought I read earlier today?
@@btcrpm yes, true, although unfortunately that still doesn't help me as we're getting a Zappi. But hopefully that'll be supported too eventually.
I just want to parse out a little arithmetic and accounting here, altho you could extract these points from T&K's excellent prez. Here goes.
Typically (say Octopus; some others too) you pay /Kwh: nearly 40p peak + 10p off-peak.
This single factor: off-peak vs peak - is the #1 ISSUE. It *OVERWHELMS* all else.
The small print of your electric provider deal, and your home-insurance is *CRITICAL*.
If your battery + heating system is correctly sized, off-peak covers nearly everything. So..
PV panels save you off-peak so under 10p/KWh. Typically, about 300 GBP/year.
Batteries+inverter save you about half total single-rate spend: say 1500 GBP/year.
So a battery+inverter spend of 7K5 GBP pays off in 5 years.
Solar panels spend 5K GBP never pays off, if you take interest charges into account.
Running your heat-pump off battery, is *CRITICAL*, and in fact, as in my case, it may not be possible to run a heat-pump at all without the battery!?!
If you are forced to get 3-phase conversion, it can totally overwhelm all other costs. Still worse, provider might give you a 3-year lead time. You are at the mercy of your provider.
Yeah, I calculated we'd save about £2k a year by combining PV, batteries, and heat pump. Total cost of all that was about £22k so accounting for replacing the inverter after 10 years, it'd pay off in about 12 years. The PV and battery make the heat pump significantly cheaper to run, as you point out.
You are assuming that your batteries will be fully discharged before the nightly cheap tariff. Given that you will have a solar array that would not be a common occurrence. December will be the worst month for the solar array. My 5.9KW array generated 104Kwh. The Giv energy kit can be installed outside as it is waterproof - that is where mine is going.
Take a look at the video I posted earlier today 😉
I have DIY experience with power walls and solar.
I use LFP batteries & Victron hardware.
If the inverters you’re buying don’t contain automatic crossover switches for grid outages, Sterling sells them.
Interesting you’re using Octopus Go & not Intelligent; Intelligent off-peak is 23:30 - 05:30.
BTW Tesla has been using LFP batteries in their RWD cars since Sept. ‘21.
Yeah, I've looked into Intelligent but at present they don't support all cars or chargers, so we wouldn't be able to use it at the moment. Hopefully they'll add more supported cars and chargers in due course though, so I'm keeping my eye on it, for sure. I recently found out about Tesla using LFP batteries, which is very interesting. I wonder if more EVs will start using them in future.
This presents as if it is an advert for GivEnergy under the guise of being objective. Tim obfuscates when SolarEdge has an advantage - for instance the solaredge option does have power cut backup.
I'm sorry it came across that way to you. That was not my intention and this is not an advert. This is also an old video now so things will have changed since I published it. I also said I didn't know if solaredge had power cut backup or not, as I couldn't find that information at the time.
Octopus Go is only available if you have an electric vehicle (and it it has to be one of a few selected models & you have Octopus recommended charger unit).
Go does require an EV, yes, but I think you're thinking of Intelligent Octopus for the specific cars or charger types. You can have any EV with Go.
@@TimAndKatsGreenWalk this is what I was told by Octopus when I spoke to them last week. Where did you get your info from and when?
@@barryfitzpatrick4987 the Octopus website last week.
@@barryfitzpatrick4987 octopus.energy/go/
@@barryfitzpatrick4987 octopus.energy/intelligent-octopus/
what about using lg chem batteries
There are so many batteries out there now if I included every one in this video it'd be 5 hours long. I did look at the LG Chem batteries but they weren't ones my installer worked with. These were the two types they did so these are the ones I compared.
Look at switching to Octopus intelligent tariff. Same as Go but two extra hours off peak.
Yeah, I'd spotted that. It's something I'll be looking into later for sure.
Ah, it's not currently compatible with the car we're getting (Fiat 500e). I'll keep my eye on it though.
@@TimAndKatsGreenWalk there you go I’ve learnt something today.
Inverters, have you looked at the Sun Synk 3.6 or above which has most of your requirements built in.
@@gavlarp257 oh, I have not. I'll take a look, thanks!
Very informative presentation
Thank you.
the GivEnergy hybrid 5 gen 2 also charges battery only at 3.6kW !
Yup, I have been made aware of that. I knew there was going to be something I missed!
@@TimAndKatsGreenWalk what did you go with in the end?
@@wakkadakkaify option 3 but with a 9.5 + 5.2 kWh battery combo. I did some more detailed calculations and decided two 9.5s were unnecessary, and I couldn't charge them in 4 hrs anyway (see more recent videos about that).