I've been with Octopus for about two and a half years but I changed to FLUX just over 2 weeks ago. The results are FANTASTIC. I have a 5.6kW array of panels and battery storage of 11.6kWh. My house is 100% electric - no gas. The house has all the usual domestic appliances - two large freezers and two fridges, two electric ovens and an induction hob, washing machine, tumble dryer, two large screen tv's, a hot tub and a charge point for my EV. So our daily load is significant. I run an air source heat pump for heating and hot water. Since changing to FLUX I have only used mains power for three hours a day - during the low cost FLUX cheap period between 2am and 5am. So my batteries get charged during the day from the sun when it's not too cloudy and from the mains during the cheap rate period. Each day I've used NO MAINS ELECTRIC between 5:01 am and 2:00 am the next day - it's all come from the batteries. We haven't even needed to set timers to run stuff in the cheap period, except for charging the EV. On three days it's been fairly cloudy all day and on four days it's been sunny So I've used 139.9 kWh at my cheap rate of 19.4p (£27.14) and exported 29.22 kWh at 34.76p (£10.15). So my total outlay including running my house, a hot tub, an air source heat pump and my EV has been £16.99 for the week. The EV has used about 82kWh, 47kWh from the batteries or solar and 35kWh from the mains at 19.4p So the car has cost me £6.79 to do 220 miles because most of the power was from the sun (via the house battery) and the rest from cheap rate power. If I was running my pervious car which did 50mpg on diesel that would have been around £30.00 My Octopus rates are as follows (they vary depending where you are in the UK) Cheap rate - 19.4p (import) & 8.44p (export) Standard rate - 32.4p and 21.4p Peak rate - 45.26p and 34.76p I think, looking at the temperatures and the amount of sun etc over the last week this will be a fairly average week for me over the year. so I can infer a total energy bill of around £880 a year or £73 a month. These are rough figures so please don't nit-pick - I'm just trying to give an idea of how good this tariff is likely to be. I hope it hasn't been too boring or complicated. Thanks for the video Gary - clear and easy to watch. Keep them coming
Thanks for sharing the details around your experience with Flux, Scott. Amazing results and I'm sure this will help persuade people who are not sure about Flux, to give it a go! Thanks also of the kind words about my videos :-)
Thanks for your statistical info, gives me confidence. One query is I've contacted Octopus by email concerned about my feed in tariff standing, I want to migrate the same rate from my recent move from SSE. Octopus have not replied yet after a week, so how does one communicate if I want to change my plan to Octopus Flux, or a plan that's suitable for my system??
I have much the same size system ,thou my battery is slightly smaller.. As I live alone I use very little power,so my battery is in use all the time ,I import around .25kwh a day and in the last month consumed 115kwh while exporting 138kwh via solar... I do not run an EV (in my case it just does not make financial sense to purchase a £30 000 car when my old car is running so well,) Hopefully by the end of the yearly solar season (which I think of at the end of Nov ,when I start cooking on gas ) I hope to have at least £200 in credit with Octopus , and with that cedit use to finance to dark days of winter,which is around 75days or back to cooking electric middle to late Feb....... The thing I am looking at is this, ,,Octopus standing charge for me is 42p aday,,(I think) per year thats £153 and thats just electric I think the gas is another £100 ayear, so £250 ayear down the swanny for what!!!!! I am considering switching to Utilta for my imported energy and keeping Octopus for my export.. Utilta has no standing charge and is a prepaid energy,,so in theroy I could buy and save credit with them or save the cash myself and just buy as needed..The price of there energy is more expensive but even so .I think it could work.... Regarding using your battery to store then export ,,, in my case I have to wish to do that,,I am 67 and want my battery to last my lifetime.. so I do not want too work it that hard...Treat your battery like a baby care for it and hopefully it will last ,,,regards
Many thanks for your informative video. I have joined octopus on the flux tarrif using your link to get both of us the £50 reward. Even in March I am powering numerous appliances and exporting up to 5KWh per day. So far I have not programmed my solar/battery system to download during the three hour cheap period but will do so soon Many thanks for your informative videos I have subscribed
Hi Philip, you're most welcome - and thank you so much for using my referral code - that helps me an incredible amount :-) Btw, I'm working on a web app version of the utility - it's still quite early but it's shaping up nicely and also fully functional. If you'd like to try it, please send me an email to "me" followed by an at symbol, then my channel name (all one word) and finally dot com, and I'll reply with a link to it.
Brilliant explanation of what’s available. I feel we’re in a ‘coming of age’ period for how and when we consume power and it’s positive impact on the grid. Driven by Octopus where the enablers are solar, home batteries and EV’s. Exciting times. I have an EV and am still seriously considering a move to Flux from Intelligent. It helps that we have a SW facing roof where this lends itself to the peak period for export. Great videos Gary. Looking forward to the rest of the series.
Thanks Jonathan - I totally agree. We're just getting started, I reckon :-) And yes, I was going to mention in the video that any roof with a partial/full West-facing aspect, would be very good for Flux (but I forgot!) :-)
Just had Solar installed and was looking for info on Tariffs, this is an excellent video made by a great presenter and an easy to understand description throughout
Hi Aaron - thank you so much for the super thanks - very kind of you, and I'm very happy to have been able to help you. I'll keep the videos coming... :-)
Keep on doing what your doing Gary. We all need people like yourself. My battery system on a fully south facing roof went live last Friday. Aug 18. I have sat & watched your vids in a really serious manner & treated it all like doing a O/U degree. You pack a lot of info into your tutorials so by the same measure you put a lot of effort into what we see. Thank you. I will stand by my product selection "Cos its done now". My next minefield to cross is the Tariff affair. For next few months I will stay where I am just so I get to see actual savings. My point of reference. You manage to make a very complex & outwardly very boring subject interesting. Top man. Well done you.
Hi Rich, your comment has made my day - thank you so much for sharing! And good luck in your tariff analysis - it seems we're all spoilt for choice with smart tariffs these days (at least in the UK)...
Thank you for a very useful video. I've just had 10 4.5kw panels and a 9.5 kw Givenergy battery fitted and managed to switch from Shell to Octopus with a new smart meter fitted yesterday. Flux sounds great however we have a 12kw electric boiler and have a high consumption rate especially in winter. Ican see I'm going to need to study your chart carefully before I choose Flux or Agile. Thanks again
Hi Kevin, my pleasure to provide you with that - and now, instead of the spreadsheets, you can use my free online utility, which is easier to use. Try it here: garydoessolar.com/utilities/dailymodellingutility/ Good luck with whatever tariff you finally select! :-)
You're far too kind, Chas. But wait till you see my programming skills :-) (Actually, I used to be very good at that, but the world is changing fast and I can't keep up with it!)
At 1:15 you mention the duck curve as being the energy demand. As far as I know the duck curve is related to the solar production in relation to the demand during the day; a completely different graph than only the demand curve.
You’re right - I made a mistake, which is corrected in the video description 👍🏻 I managed to use the phrase correctly in this video though 🤣 ua-cam.com/video/WpkLX0GTSE4/v-deo.html
Thanks for you reply @GaryDoesSolar, I’ve watched most of your recent videos. I’m from The Netherlands, here we have fixed, day/night (07:00 - 21:00) or dynamic (hourly, day in advance) tariffs. I find it very challenging to determine what battery installation to get and value your views 👍
@@SanneHoekstra Certainly worth considering a battery capacity that is large enough to cover your typical daily usage. That way, you can fully charge it during the off-peak period (fixed day/night tariff) or during the cheapest hourly slots (dynamic) and it'll see you through the remainder of the day...
I really commend you for providing this insight! Unfortunately this is not translatable to the Dutch energy prices. In the Netherlands we have the “salderings regeling” that meant that you can deduct every solar generated energy from your bill (during the contract period, usually 1 year). Effectively you can use the grid as a battery from a price perspective. This is not durable obviously, you can economically use the grid as a seasonal battery, while there is no seasonal energetic storage in place. With the politics lagging behind the energy companies are starting to change for yearly returned energy by households. Just to summarize, it’s a mess….
I agree with your view. Having at least 100% of your daily usage in battery available will turn out to be profitable (economically and ecologically) in the long term. Politics and price have to follow reality in the long term… 👍
*** NOTES SINCE PUBLICATION *** 1. Oops - it was pointed out to me that the "duck curve" is actually to do with solar production, not demand (sorry about that). 2. The Octopus Eco7 rates are slightly different than in the video - the off-peak rate of Eco7 is actually higher than Go. 3. I've been told that it's possible to have Octopus Go and and also to be signed up to Scottish Power's SEG export at 12p (with no extra standing charge). So that makes Go even better! 🙂 4. Here is a link to the utility I covered in the video - please feel free to use, but as it could contain bugs, no warranty is provided. Please use at your own risk: www.garydoessolar.com/utilities/fluxcalculator/index.html If anyone finds a bug, let me know and I'll try to fix. I'd also be happy to people to work on this, improving it. If you message me with a copy of your new version, I'll add it to the website, of course crediting you. 🙂 I've been asked how you can support me in my work if you're already on Octopus. I'm happy that you're getting something from my videos, but you can always buy me a "coffee" using this link: www.buymeacoffee.com/GaryDoesSolar - thank you! 🙂
Thanks Gary this will be really helpful for me. I'm currently getting quotes for different size arrays and batteries and was looking at how best to use the energy it'll create.
Glad I found this video. Convinced me to increase my battery size prior to agreeing installation. I will look to increase my battery caoacity in future by adding additional batteries in parallel. Seems like basically the objective financial answer for everybody is get the biggest battery you can afford at first, it will pay for itself using flux import/peak export.
Cheers Martin - yeah, and with battery prices coming down all the time, it's a really good investment. Not sure if you saw this video I made yet, talking about that, but here's the link: ua-cam.com/video/3vwDrfuXyik/v-deo.html
I’ve got a GivEnergy 3.6kw inverter this charges at 2.5kw max. If I was thinking of installing solar/battery I’d get as big a battery that I could afford and a 5kw inverter. The inverter is the limiting factor. Excellent idea for the series Gary, thanks.
Thanks Ian - yeah, I have the 5kW version of that, but the charge rate is limited to 3.6kW - sometime's I'm pulling 6kW so a bit of a problem :-/ Will think about a video looking into these rates in more detail... thanks
Here in South Australia the off-peak is 10am to 3pm when all the rooftop solar swamps the grid. On some days, rooftop solar output exceeds demand and some inverters have to be turned off to reduce generation. On the wholesale market, electricity is often negatively priced between 10 and 3. Our problem is a lack of cheap power during peak and overnight.
@@GaryDoesSolar for people on wholesale (almost nobody) a battery makes sense. On normal retail plans they are too expensive and will never payback the investment.
I have PV/Battery. Solax. On Flux. During the darker months I charge my batteries during the off peak hours. I then let my batteries discharge from 5am. I then force them to "top up" for 2 hours prior to the higher rate. This ensures I am keeping my batteries full at all times and exporting the maximum to the grid; and that my batteries are depleted during the higher rate hours. I have a 9KW battery systerm but wish I had gone for double that size as my family use a lot of power in the evening. If you can afford it, go big on battery stroage.
Super work, well done. One strange thing: I'm on Octopus Go though we do NOT have an EV. We have up to 5kW from solar and a Tesla Powerwall 2. It looks like Flux should be the way to go, but we are very high energy users (I run a business from home, computers and other equipment run most of the time), so outside the peak of summer our battery will often be nearly flat by 4pm. How did we get onto Go without an EV? We were ported across from the Bulb EV tariff which didn't require an EV.
Thank you! Yeah, Flux is a pretty attractive tariff :-) IU've made available a web app now for people to see if Flux is right for them: garydoessolar.com/utilities/dailymodellingutility/
First class video again Gary, many thanks. I have 9 KW of PV 2 x 8.2 KW Givenergy batteries + an EV and a PHEV. Being on the early - high- FiT the calculation for me is a trade off between which tariff and the FiT. Will be investigating Octopus as my tie in with EDF expires soon. Having an EV tariff has enabled me to charge the batteries through the dark winter months - its the way to go.
Hi Alan, that's an impressive setup - I'm jealous! And being on FiT is just a dream as well. Your early investment must be paying off incredibly well :-) As you can probably tell, I love everything about Octopus Energy - they're just doing things right. I'm wedded to the mobile industry with my career, but if I wasn't (and who knows what might happen in the future), I'd be interested in working for those guys!
Alan, I have a similar set up to you (17.5 storage and on FIT) but without the PHEV. if you can't move to Octopus Intelligent (they will only deal with certain cars and EV Chargers, I have Merc and Zappi, neither of which are compatible) then look at British Gas Electric Driver. their price is the same as Octopus Go but you get a 5 hour window to charge instead of 4. For me that means I can fully charge the batteries every night in winter and get 35kWh into the car.
Marvellous! I have been saying we need a big spreadsheet to understand all the variables, but I was daunted at the prospect. I will check out all your videos as the first one I found was packed with useful information.
Great video, and a superb spreadsheet! Just the kind of thing I wanted to try to do but, seeing yours saved me SO MUCH effort, and made me realise my skills probably werent' good enough anyway! :) Donation on its way!
Hi, I have just found your channel and find interesting, I wish there had been a similar amount of detail when we got solar panels 7 years ago. One point to note is that for people who are still on the uk gov FIT scheme, the PV export price we get is ~5p per kwh (it depend on when you entered the scheme) which is significantly less than the current octopus rate (~15p per kwh) BUT I get paid based on a "deemed" export of 50% of my generation when in fact we only export about 10% of our generation, so this alters the economics.
Hi Carol, thanks for sharing your experiences with FiT. It was a great scheme, and kick started consumer solar for the UK. Not available to anyone today, but Tariffs like Flux provide something close(ish) :-)
Gary, really clear content, formalised what i thought i understood. Friend and i decided to buy identical systems. Ordering next week 16x400W, GivEnergy 5.0 inverter & 9.5kW battery. For 2 systems supplier provides scaffolding FOC. 👍
@Chelle Coulson a touch under £14k. That includes discount for buying 2 systems and the company offered me £250 introduction free for the 2nd customer, which i further discounted £125 each system 🤣
@Chelle Coulson just for info, we both decided that we wanted to buy/install through a local company, rather than a web based entity. The company we will order from mentioned that they are frequently approached by said entity to quote to install their system or rectify. We're in Dorset, not sure if that makes any difference 🤔
Hi, great video, at moment trying to decide whether to increase battery storage from just 5kwh. Watching with interest as at moment cannot financially justify increase. Thanks
Great video thanks Gary. We got solar and tesla powerwall last September and were able to get onto the Octopus Tesla Energy plan which is soooo good from a money point of view as it's fully symmetrical. On sunny days we make a really large profit on energy exported. However we got a notification when they launched Flux that this plan was now discontinued and we'll be forced to change in September. It's quite unfortunate because the tariff was one of the main reasons we decided to shell out for solar, the payback was going to be around 10-15 years but now with flux I think we may be out of pocket with the solar. However, at least we're helping the grid and the environment so I guess it's still worth it :)
Hi Matt - thanks for the kind words :-) Yeah, a shame they're stopping the Tesla Energy Plan - I guess you've had a good run at it. You might surprise yourself with Flux though, although having an EV does make it a little less lucrative. Might be worth you watching this video, where Anthony (who also has a Tesla) carries out an in-depth financial analysis of different Octopus tariffs: ua-cam.com/video/kWoBzds07Y0/v-deo.html
Thanks Scott - yeah, it does take quite a few hours, but I'd like to think I'm getting a bit quicker at it (I'm sure the reality is I'm not though - lol). I'll keep the videos coming...
Thanks Gary, I've got a 5kw Solis inverter & 14 375W PV panels,a myenergi Eddi for my Hot Water (instead of using my Oil Boiler to heat the water) and a Solax X1-Fit inverter and 3, 5kw Solax batteries for now I'm going to stay on Octopus Agile and Outgoing Agile Octopus for my export having only had the system fully installed this winter and waiting forever for the DNO permission I'm not actually sure what my Leccy Bill will be in Summer but so far I'm very pleased with my system, I'll keep watching your Channel to see how you get on with Octopus Flux,hopefully it's the right Tariff for your family 🙏
Gary, your video was so informative. I am about to have solar and batteries installed and I think Flux will be ideal for me. Thanks for your hard work.
Hi there Jean - good luck with your installation, and all the best with your Flux tariff - I think it's a great one! My pleasure to bring you videos like this :-)
Hi Jon, my pleasure! And very happy to help you out. I'm in the middle of developing a coded version of the spreadsheet, as the spreadsheet is too unwieldy now. Will release the link for it shortly :-)
Super helpful video Gary. Thank you. Our Solar PV system went live just 3 weeks ago and is already reducing our grid consumption by almost 70% (and that in a not-so-sunny Dumfries!) I am already thinking of adding a second battery to reduce our exports to grid and the Octopus Flux tariff will make a second battery even more financially viable. The only (slight) stumbling block is that I now need to really get my head around how to correctly set up my Solis invertor to deal with forced imports and exports!
Great news about your grid consumption - and hopefully a lot more sunshine over the coming months! Yeah, I'm hearing that quite a few brands of battery don't handle forced export very well, but forced import should be possible, given that off-peak rates have been around longer than solar batteries. Good luck in your research on Solis, and thanks for your kind words about my video :-)
Great video Gary. Looking forward to your new utility (found the last one very helpful). My rough calculations show Flux is absolutely the way to go for us. Our system doesn’t allow force discharge of the battery, but even without that I think it will be a real winner.
Thanks, Stephen. Yeah, I guess all the batteries are different. But at least you can hopefully cover your load with the battery during the peak period, and the sun should still be around to provide some profitable export. :-)
Not sure the short charging period will work on a smaller system , 3.6 kw inverter and 4kwp panels , during the winter with much reduced solar input. I think we would need to switch to a better charging period for this time.
@@GaryDoesSolar also the other thing to consider is battery temperature. I went through this winter and on a couple of nights my batteries went under 5c (4.5c) and I noticed thier charge rate during eco7 dropped sharply to just 10A per battery (about 500watts) i have 4 batteries (20kwh) but a drop in charge rate to 2kwh would take 9 hours to charge from the maximum discharge level of 90% (a battery SOC of 10%) Not enough time to charge during economy7 and definitely not enough to charge during 4 hour octopus go or 3 hour octopus flux. Conversely at 13c, my batteries can charge at their full sustained 0.5c rate 50A per battery (2.7kw) meaning 10.8kw which is beyond my inverter charge rate. The key note from this, most batteries are installed in a loft or garage.... uninsulated... so exposed to night cold. Its something to consider as you may mot be able to charge fast enough in tbe charging window.
Great video - thanks. We’re currently on Go as we have an EV. I’m considering solar and batteries but it’s so difficult now to work out break even etc because of tariffs like this! Hurts my head!
Thanks so much, I had my 4.2kw/h solar/batteries (12kw) installed in Oct 22 and as yet have not looked at the export but whilst I am away on holiday monitoring my battery charging/export of energy. I have just filled in the SEG forms with octopus and currently on Octo Go Tarrif with the 7.5p import cost 12.30-0430. using this time to fill batteries but from about 10am I am exporting as the batteries are full. This is excellent modelling but I still need to get head around numbers, and from this video best I stay on my Go until September when it expires, although I am going to generate quite a lot of energy - will fill 80% on battery and charge my Mini via Zappi..
Hi Tony, you're very welcome. I've not long released a web version of the utility that you might like to try as well: garydoessolar.com/utilities/dailymodellingutility/
Thanks for this video Gary and for your work in the spreadsheet. This couldn’t have come at a better time for me as this week we have had PV + batteries installed and I am just awaiting the paperwork that will allow me to switch to Flux.
Hi, lovely video as always, thank you 🙂. I have solar and battery, the GE AIO and am moving to Octopus Flux. I want to automate my system to achieve the following... 1: 2am to 5am - charger to say 100% (the low-cost period) 2: 5am to 4pm - use solar plus battery but keeping sufficient charge to cover the peak period requirement. This is where it would be great if I could set the battery to not fall below say 50%, but only between these times. 3: 4pm to 7pm - use battery only to avoid the high peak rate period. 4: 7pm to 2am the following day - continue to use battery down to the reserve level. The above cycle to repeat every day without any input from the user, must be a set once and forget. I can achieve quite a lot of this in the GE portal but not all of it (do need to dive into the Remote Control settings). Have you any suggestions? Thanks
Thanks for the great feedback! :-) Worth also watching this video I made on how to get the best from tariffs like Octopus Flux - could give you different ideas: ua-cam.com/video/dGpsN8-1Fx4/v-deo.html For some information on how to program your GE settings, this video might be good: ua-cam.com/video/DDDd_j8O5s4/v-deo.html
A nice explanation on the Flux tariff options.. I had a look are your spreadsheet, but at the moment it doesn't really manage to cater for the setup I have in place. I have 7.5kw of generation, 7.5kwh of battery, and an inverter that can push about 3.6kw to charge. I have another inverter that can push the excess solar to the grid when the batteries are charging at capacity. This is all getting a bit complex for Excel formulae... What I need to do is pull down the raw information from the Invertor and generation logs... This will tell me the flow power to / from the grid (AC side) and the flow through the invertor (DC side and conversion to home side AC)... Those two curves on a daily pattern tell me my actual usage stats, and I can code that to calculate the costs, and allow for the usage of the Flux tariff to calculate what i would have got from it for a given period... At a gut feel though, I think that this tariff is pretty good for a house with solar and battery (though I question if that's essential) but the reduced low rate period, (3 hrs) and higher cost of that minimum period (compared to cheapest EV charging options), basically mean that this is not a tariff maximising benefits for a home with an EV that needs a lot of home charging. It might be ok for a low - medium useage of EV's..
Hi Andrew, yeah - that's quite a complex setup. You're right though, the spreadsheet is getting out of hand, so I'm currently coding up a webpage to replace it... So far, it's not looking too bad. I agree with your thoughts on Flux.
Thanks for the vlog, just subscribed. I must admit the Flex tariff doesn’t really entice me so I guess I’ll have to buy an old cheap EV as a third car to get on the Go tariff.
Thanks for subscribing Philip :-) Haha, that could be a good strategy. I'm getting an EV charger fitted this week, but no EV yet(!) - I'll need to wait until prices come down...
@@GaryDoesSolar I have a legacy 2.2kW array on a 2011 FIT plus I've just added a 6.5kW array both are on a south facing roof. As you, I have a GE 5.0 Hy plus two GE9.5kW batteries on the new array. Interestingly the 2.2kW array contributes to charging the batteries which I wasn't expecting. The DNO capped my export at 4kWh so no real incentive to export, DNO's don't seem to have the infrastructure to have a truly distributed local solar and battery system and the Government don't issue any targets to the DNO's to strengthen the system
@@Flood51 Your two arrays sound ok. And you'll have had an excellent return on your FiT over the years, I'm guessing? I'm capped at 5kWh so only just above you, and I reckon that over the longer term, it could be good. My array is 7kWp and with the two 9.5kW batteries and Flux, my numbers tell me that I could potentially earn £4/day (including all my normal usage covered). It seems too good to be true so I'm checking my utility hasn't got some major bug in it!! 🤣I agree with you about the DNOs - it's crazy that we seem to know what's required, but those in a position of power do not... 🤷♀
No worries, Dan. How are you finding the world of being a UA-camr? It's quite involved, yeah? I'll release the utility very soon, just a couple of things to tidy up - it'll have a massive disclaimer on it too, as I'm sure there will still be bugs! :-)
@@GaryDoesSolar Very involved but I’m really enjoying it! Hoping to get another one out this weekend. Definitely appeals to my creative side, although I need to get the production quality up a lot I think. What do you use for editing?
@@DanEVSolar7 I used to use iMovie, which is ok, but I now use Final Cut Pro, which is really powerful, and relatively easy to use (lots of options and controls, which are quite scary in the beginning though!). All my graphics and animations are PowerPoint, would you believe. Amateur, but they come out not too bad. I think I need a better microphone though...
Excellent video and web utility, THANKS! One question on the utility: when modelling an Autumn quarter using a max average array power generation of 2.4kWp with a 9.6kWh battery, using a 3.8kW inverter produces a higher daily profit figure than using a 5kW inverter. Would you expect this? Just at the quote stage for installation and trying to assess whether the extra 1.2kW and a 12 week delay for DNO approval is worthwhile.
Thanks for the very kind words, Ray :-) Now, on the face of it, I would not expect a lower-powered inverter to result in a greater profit for the day. I just tried those numbers here and there is no difference in profit (as the solar generation doesn't get near even the lower inverter limit). Could you try with the latest version of the utility please and let me know... thanks!
Just modelled the same numbers in the new version and clearly a better result with the 5kw inverter as one would expect. The new version looks great BTW. I see that you now don't have to calculate the maximum achievable array output by quarter. Is this now included within the utility based on array orientation entered under the Solar Array Performance box? On that point, my planned array will achieve a total of 6kWp but with 4kWp from the directly south facing roof and 2kWp from the directly east facing roof. How is is best to model that performance in the utility please? Many thanks Gary!
@@rayscogings3700 Hi Ray, great to hear that the utility is working for you! Now, yeah - modelling two arrays on different orientations is actually quite tricky. Currently, the solar model is only optimal for a single South-facing array, but it's something I'm thinking about for a more powerful utility down the line.
Hi Gary, thanks for taking the time to explain the electricity tariffs, I just signed up to Octopus Flux (used your referral code) after installing a bit more solar and new batteries. All going well until by DNO refused to allow me to export any power from my battery to the grid, this seems counter intuitive to the aim of balancing the grid and put a spoke into my calculations. Do you know if there is an appeals process?
Thank you so much for considering me when joining up with Octopus Energy - that means a lot to me. And sorry to hear that your DNO is blocking you from exporting to the grid from your battery. In case I missed it, could you tell me about your situation again please? Did you already have panels and are now adding a battery?
At present I am on the Octopus Tesla tariff, but that is coming to an end late this year/early next. With PV and a Powerwall 2 + an EV6 it will be challenging to find the best replacement ! I will be following your series on this with great interest !!
We’re an octopus customer in rented social housing with solar panels, but no batteries When we moved in the analog meter went backwards in bright sunshine However changing to octopus required a smart meter On bright days electricity is £0.00
It must have been so strange to see your analog meter going backwards! Great to hear you're not having to pay for electricity on those sunny days - every penny counts! :-)
I think the Flexible Octopus tariff is still the simplest as you can just leave your settings alone, i.e. have your battery storage between 12:30 to 7:30 when economy 7 charge is 17.73 per KWh then use your battery for your daily / evening time, if your battery is sufficient you can run on the stored economy 7 power all day, plus any solar can help top up the battery and what you don't use Octopus buy for 15p per KWh. On a Sunny day life is great and on a cloudy day you are still only paying 17.73p per KWh. We just try to leave our high usage days to sunny days when we have surplus solar if possible.
Hi Paul, Provided your battery can cover all the day's electricity requirement, this is a very nice and simple strategy - sometimes the simplest ways are best! :-) I'm currently building a coded version of the utility presented in the video, and you've got me thinking... thank you!
Great worksheet Gary. I did notice an possible error in one of your formulas (in column M) which seems to miscalculate the discharge rate of the battery during the "FC" period. I believe if the battery is in this mode, then it will be forced into a charge rate so there should be no discharge possible, however your current formula seems to think there is a discharge value if the consumption is high over this period (as it is with me with my immersion heater and EVs charging at this time). I've made a quick update to cell M4 (and copied down) to adjust for this: =IF($K4="FD",-MIN(MAX(MAX($C$7-$J4,0),0),N3*(1-$C$11),$C$13),IF($K4="FC",0,-MIN(MAX(H4-J4,0),N3*(1-$C$11),$C$13))). May need some sense checking though. Keep up the great work.
Hi Mat - thanks, and also thank you for taking the time to look into this bug! :-) What I'll do is update the spreadsheet and upload it as a new version that people can use! Since publishing, I've been working (this week) on a coded web version - which has completely different logic, but I can compare the output of this new version against your suggested change as a sanity check! Thanks again :-)
Actually, Mat - is it M4 or K4? Maybe the best way is if you could email me a copy of the spreadsheet with your change in it, if that's ok? Send to "me" then at symbol then my channel name (all one word) followed by dot com. Many thanks! :-)
Thanks Keith - I plan to cover Agile in part two of this series - I really like the fact that Octopus is so forward thinking on tariffs Being paid for taking load off the grid sounds marvellous to me! :-)
Great video! Is there a way to automate all the charging and discharging? I have a 5kw array, with the Gen 2 Giv Energy Hybrid and 2x 5Kw batteries. The only downside I see for me is the Gen 2 Giv Energy charge rate is only 2.4Kw so I wouldn't be able to fill the batteries in 3 hours.
Hi Rohan, you're most welcome. Is this your inverter? www.givenergy.co.uk/pdfs/products/datasheets/giv-hy-3-6-gen-2.pdf In which case, the charge rate is 3.6kW, but maybe your batteries are limiting the rate? I also have GivEnergy products: a Gen 2 GivEnergy Hybrid (5kW) and 2 x 9.5kWh batteries. I can only charge about half the batteries as well, but I'm ok with that because as we head Into sunnier days, the increased solar will quickly fill the remainder.
@@GaryDoesSolar Sorry, I was wrong, I have the Gen 1 inverter which is limited to 2.4kw charge and discharge. I think they announced the 3.6kw version a month after I took delivery of mine!
That's very kind of you, Ecobubl - and just to let you know, the solar and battery installation you fitted for me week before last is performing amazingly :-) I'll be making a video about it shortly...
wow what great info, I've ordered solar and will have a 10.5Kw battery plus I have a EV so this makes things really worth it I might think about getting a 3rd battery as well
Thank you for the feedback - very much appreciated! And great that you're starting your solar journey :-) Haha - yeah, big battery installations might become all the rage soon!
great vid - and thanks for the spreadsheet - who doesnt like a spreadsheet after all. Made the switch to Flux ealier today and its clearly aimed at the home owner micro generators- good for Octopus, and as you detailed each user shifting the curve slightly benefits everyone and Octopus. Ive set my inverter initially to export only for just one of the peak hours, time will tell if i can be bolder, but i seem to be runnig at twice your nighttime and nothing is running rate.
Thanks Charlie - I think my spreadsheet is starting to get out of hand though - lol. I'll likely code it up on a website instead... I didn't understand the very last part of your comment - could you restate please?
Great work again Gary. I am on Octopus Flux and trying to work out whether to use my battery to minimise import (and take export benefit as a second priority) or to maximise export and accept some import after the evening peak (as your utility does). I haven't yet convinced myself that the latter is worth the extra battery throughput and degradation for relatively modest extra import income. Looking forward to your utility. My present strategy is a mix of the above. I avoid import before dawn by charging to at least 20% overnight (may not need to charge at all if evening consumption is low) and I avoid import after the evening peak by only force discharging to >45%. This works ok for my system with the present level of sunshine, but as I say above, I am not sure what the optimum strategy is.
Thanks for the kind words :-) Yeah, developing an optimum strategy is really hard - I guess the only real way is a bit of trial and error (and a lot of data analysis!). One feedback I had on the utility is that because of the "power factor" of certain appliances, 1kWh of charge into a battery might not provide 1kWh of useful power for appliances with a low power factor (anything with a motor it seems). I'll need to look into this...
@@GaryDoesSolar you don't need to worry about power factor. Poor power factor (e.g. a motor with poor power factor compensation) means the load has to be provided with reactive power (kVAr) in addition to active power (kW). Reactive power only exists for AC systems so the "real" energy kWh is provided by the DC system (PV or battery) and the "imaginary" reactive "energy" kVArh is provided by the grid connection or produced out of thin air by the magic of your inverter (at the expense of slightly increased inverter losses)
Hi Gary, an update, on contacting the DNO (Northern Powergrid) myself they have agreed to let me export from my battery as well, seems that they have updated their policy so good news! - I had two solar installations and have added batteries and a new solar install with battery.
Thank you for the video. As we have a GivEnergy 8.2kwh battery and we are on Octopus Flux, I did a forced discharge test and took the readings from the smart meter the next day. The battery exported 6.9kwh from 100% charged all the way down to 0 (didn't stop at 4%). It used 9.8 kWh to fully charge back to 100%. The round trip efficiency of the battery is only 70% and I have now stopped discharging to the grid during peak hours as the gain is just 4.5p/ kWh and in my opinion doesn't worth it.
You're most welcome about the video. A 70% round-trip efficiency seems rather low - I'd be expecting around 90%. Maybe something to ask GivEnergy about... Shame also that the battery discharged to 0% - it should not have done that :-/
@@GaryDoesSolar If you do test your your battery, remember to record its temperature. GivEnergy responded today and they are asking for it. Looks like I will do a repeat test soon
Unfortunatelly, I don't own a house and I don't think that I can buy one the next 5-10 years. So, no PVs or batteries for me. I don't charge my car so often (30Kwh every 2 weeks) and I have a big family (5 people) and everybody works on day-night shifts every week. We spend a lot of power in daytime and Octopus programs won't save me some money. Now I pay a flat rate of 27p/Kwh at British Gas. But I love your videos, you are doing the most simple and informative videos on that subject.
Thanks Chris - and one day I hope to get an EV myself. Worth keeping an eye on the various tariffs on offer (e.g. Octopus Agile) as they might just work in your situation (I'm thinking perhaps a battery only install to soak up cheap electricity periods - prices may need to drop a little first though...)
Hi Gary, Thanks for another in depth and thorough video. (Do I detect a fellow Engineer? 😀). I have just had a 6.7 kWp array, GivEnergy 5kW inverter and 9.5kW battery installed. My charge / discharge rate seems limited to 2.6kW so I can't fully charge / discharge in the 3 hour Flux / Peak windows. You have a similar setup, but with two of these batteries. (@7:11) Is your charge / discharge rate of 3.6 kW per battery, or in total, perhaps now limited by the inverter?
Hi Nick, thanks very much for the kind words - great to get this kind of feedback :-) Now, yeah I have pretty much the same setup as you! My inverter and batteries are Generation 2, which means it can charge and discharge at 3.6kW. If I remember correctly, the previous generation had a charge/discharge limit of 2.6kW. I've set things so that I'm charging all 3 hours of the Flux off-peak period, up to a maximum of 40%. This means I get sufficient cheap energy if the day is not so sunny, and I still have more that half the battery to charge via solar. Maybe you could do something similar, perhaps?
A brilliant summary video Gary. Very much enjoyed it. Looking forward to working through your back-catalogue and future videos. Clear, factual and inspiring. I'm in the middle of moving to Flux and its exciting being part of the future. Unfortunately we only have a 3.1 kWp array and 3.5 kWh battery for now but planning to roughly double both once we get an electric car. We got a power diverter when we had the installation but as per your other video I'm now wondering whether it makes sense to run it now we are on Flux.
Hi Toby, thanks for taking the time to comment (and also for the great feedback!) Hope you enjoy my other videos! I've been on Flux for a few days now and I can't believe that I'm being paid so much to export! I'm almost feeling guilty about it! Lol I'm guessing your current array and battery is in line with your electricity usage, so I wouldn't worry too much. You'll still be exporting a lot as the days get sunnier. And yeah, on the solar diverter - it's a real shame that with high export rates, it longer makes any financial sense at the moment, but who knows, if electricity prices start to come down (and consequently, export rates come down below 12p/kWh) then they could come back into fashion...
Great explanation of Octopus Flux and it's potential benefits. I've only recently installed solar / battery and I'm looking how to use it effectively. Are you planning to give an hints/tips on how to configure Inverters in order to be able to obtain the benefits you describe from Octopus Flux?
Main problem is during winter or poor solar production. 3 hour charging window at night limits on appliance usage. A 300L water tank will take more than 3 hours to fully heat up to 60c. This tariff only works if you retain the battery charge for peak use and hope your solar can retain/ aid its charge. Cloud / weather and winter is its enemy
That's true, and it might not always be possible to do that. You might be interested to watch this video I made on solar diverters - might cause you to think about the benefits of using that (I used to be a fan of them, but now I'm not): ua-cam.com/video/6zc1g1bz0eA/v-deo.html
Hi Gary. May I take some screenshots from your video on tariffs to use at a presentation I’m giving at my village hall. I would of course reference your channel. Rob
I've always wanted a solar setup, I've been subscribed for some time now but only out of interest. I just bought a house which amazingly has 18 solar panels fitted on a south facing roof with 2 batteries. Bit of a dream come true, but I'm totally overwhelmed by the admin of it all. We have a young family, so I don't have much spare time to be watching a hundred youtube videos on the subject and I have no idea how much energy we'll use in the new house. Looking at Octopus, I'm tempted to just go "fixed" for 12 months until I can get a handle of our usage and how I'm supposed to manage the batteries. Hopefully I'm not doing a dumb 👀
Great to hear about your new house! Yeah, no harm at all, staying on a standard tariff for a year until you get time to look at everything. But if you have, or are thinking about about getting an EV, I would strongly recommend you switching to an EV-specific tariff (like Intelligent Octopus Flux, for example). Good luck with the solar installation. If it's useful to you, you can book some of my time where, in say 30 minutes, we could quickly ascertain a good tariff for you and the family to be on: garydoessolar.com/chatwithgary/
Hi Barry, thanks :-) Now, did you mean cell B5? This is a blank cell. Let me know which cell and I'll check it out... By the way, there is a newer Web app version of the same which you might prefer: garydoessolar.com/utilities/dailymodellingutilitytest/
@@GaryDoesSolar I just tried your Web version, and it's great! What azimouth and roof angle are the solar calculations based on? Any chance that can be editable for slightly more accurate predictions?
@@themorfill Are we talking about the same spreadsheet then? Here is the cell B5 I have in the original flux calculator spreadsheet: garydoessolar.com/files/cellb5.jpg
@@themorfill Hi Barry, great to hear! So the solar model assumes a south-facing array. That's not adjustable for the moment - but you can adjust the Maximum Array Output setting accordingly. For example, if you have a 4kWp array which faces SW, then out a value of say 3kW in.
This is a great video - thank you. I have a query re EV charging. Maybe someone can help. If I have a 6kwp array and lets say its getting 5kw in the middle of the day, but I have a 7kw EV charger, if I have a battery, theoretically I can get the extra 2kw from the battery giving 7kw charging - but can this be done through a 5kw inverter? Does the inverter need to support up to and above the EV draw?
Hi David, thanks for the kind words - much appreciated :-) Here's my understanding of how it would all work. It depends whether the battery in question is AC or DC-coupled: - A DC-coupled battery is behind the inverter so when it discharges, it is limited but the inverter's output (which in this case is already maxed out with solar). So, there will be an additional draw from the grid of 2kW to meet the needs of the EV charger. - An AC-coupled battery's output is independent of the inverter's output, so the power adds up (5kW solar + 2kW battery) to meet the needs of the EV charger.
@@GaryDoesSolar That makes sense - thank you. I've had a really good play with your Excel sheet to model outcomes (1. 6kwp+Powerwall, 2. 6Kwp+9kwh other brand, 3. 6kwp, no battery and 4. No solar, no battery.). I think you're overestimating solar generation. Your peak rate is probably right (around 40kwh per day on a 6kwp system). For reasonable accuracy though this is should be annual/365 giving 18-25 kwh per day. This is really significant.
@@dinkdankdh Thanks for the feedback on the spreadsheet. I'm actually working on a web app version of the same, and in that I think I have a better solar model. If you'd like to try an early version and give feedback, I'd very much welcome that. Just drop me an email on "me" followed by an at symbol, then my channel name (all one word) and finally dot com 👍
This was very interesting . At long last we're getting a smart meter. After an 8 month wait. My question is how easy is it to program the kit to follow your example of when to charge the battery, when to use the battery and when to feed the grid. Presumably you need to buy kit that will do it. I'm lucky we are starting from scratch. I'm in my late 70s so need a quickish payback. Thanks generally for your videos. Very interesting and informative. With the smart meter on it's way I can start planning.
Hi Allan, great that you've finally got your smart meter sorted! Now, it depends on the kit you buy. For example, if you had a Tesla Powerwall, you can program it like this chap did in a video here: ua-cam.com/video/VrKSKPrdhak/v-deo.html Good luck with whatever setup you put in place, and thanks for the kind words about my videos - I'll keep them coming! :-)
Hi Gary. I just want to draw your attention to a small think in your video "fingertip image" :) They are of high quality and stylish, but you may want to think about using the lower right corner of the image - or actually not using it. In particular, the text or a significant part of the image should not be in that position, where the UA-cam platform always places the black rectangle indicating the length of the video and now the white marking "14.20". It covers the end of the last word of the video's theme "riff?" Do you notice? It is therefore a thumbnail of approximately 300x170 pixels. So you might want to set yourself a "reserved area" in the thumbnail production medium, where at least the text shouldn't go.
Hiya - thank you for pointing this out - I checked it and you're right - it's obscuring (quite important!) text. I'll keep what you say in mind for future videos - every day I'm learning something new! :-) Thanks again
@@GaryDoesSolar You really deserve all the help you can get. Btw: I haven't watched all your videos yet, but I'm interested to know if you've ever used the real background of your shooting environment without greenscreen stuff :)
@@GaryDoesSolar Yeah :) Do you have expertise in AGM batteries? I have a tiny 240 Wp power plant and I bought a 260Ah 12V AGM battery for it. I asked the Finnish importer of this battery for all the documents, because this battery was the last one in the retail store in 10/2023 and it was a demonstration item that lacked all the documents. The importer sent me a document produced by the factory, which showed, for example, the cyclic nature of the battery if used each time: - 100%...0% gives 300 cycles - 100%...50% gives 600 cycles - 100%...70% no less than 1500 cycles
So I understandably wanted to know what 70% is as a voltage value after two hours of rest. It was not mentioned in the brochure I received. I asked for such a table separately from the importer, who replied that I cannot get one because the RITAR factory has not agreed to supply one. So I thought that maybe I need to follow a chart that I found on the internet with a google search. I concluded that by discharging the battery up to the maximum limit of 12.3 V, the battery would have a long life. After three months of use, I started to pay attention to the fact that the battery charge does not last long, and I even more wondered why the 25A 12V smart charger charges the battery from bulk phase to float phase in about an hour, when it used to take at least 5 hours. Now I approached the importer again, and said that I really need that voltage table. Now they sent it to me and it showed right away that for this battery 70% charge shows 12.6V and 12.3V means 50% charge. What do you think about this? I got the impression that RITAR is a really high-quality manufacturer. Why on earth would they not provide their dealers with such essential information? I think now I have paid for nothing because it seems to me that I have destroyed the battery in less than half a year. Am I mistaken? Thank you.
Very informative. Thanks for the spreadsheet, and thanks to everyone who has helped you to develop it. I asume you will be tackling Octopus Agile soon too. Is there anything I need to know regarding choice of hybrid inverter to make best use of that tariff automatically. I understand that GivEnergy and Fox are compatible, but do they integrate equally with these smart tariffs?
Hi Jeremy, my pleasure - glad you're getting something out of my videos. Just to let you know, the spreadsheet has now be superseded by this web utility I made - far easier to use and more informative: garydoessolar.com/utilities/dailymodellingutility/ Regarding the batteries, I can only share my experiences with GivEnergy as this is the only battery solution I've worked with (my own solution). They have facilities that allow you to force charge and discharge at certain times of the day, so great for tariffs like Octopus Flux. They also have support for Octopus Agile, but I've never tried using that yet.
Great video, Gary. I have plenty of solar and a SolarEdge inverter + battery, but am stymied by two issues. Firstly, my utility provider won’t install a smart meter as the 4G signal is apparently inadequate. And secondly, SolarEdge don’t have workable time-of-use software yet.😢
Thanks Alan. Isn't it incredible that so many manufacturers are not anticipating how the market is changing...? I've only been looking at this market for the last 8 months, and even I can see that equipment needs to have tight integration into other equipment around them, energy tariffs, the weather forecast. That's one of the reasons I went with GivEnergy - they seem to get it. Hopefully SolarEdge will wake up...
Thanks for the kind words - and my plan is to suggest some options in a future video (hopefully not too far away).... I have a GivEnergy inverter/battery myself and it seems to work well.
I moved to Flux yesterday. My setup is Sunsynk 3.6 inverter with 16Kwh battery. The 3 hours of off peak charging is not enough to top up the battery to 100%. Might have to invest in another inverter soon to double the charging capacity.
Hi Rizaul, yeah - that's a big battery compared to the inverter, but you know, over the next 6-7 months, you should get plenty sun to fill that battery anyway, yeah?
Thanks, a great explanation. I can’t have solar, drive an EV, currently on Octopus Go. I’ve enquired about battery installation but it seems Octopus doesn’t do them without solar. Any recommendations for a battery installation?
You're most welcome :-) Now, you can add easily an AC-coupled battery to your house - you'll just need to get hold of an installer (doesn't have to be Octopus). Worth checking out various solar forums like facebook.com/groups/2197329430289466 to see if a battery without solar is worth it... Good luck!
Great video Gary ... and have been contemplating Flux since it came out recently. I don't have a need for EV charging ... and my solar setup sounds ideal for the tarriff. I'm running a Sunsynk Hybrid inverter 5.5kw with 10.24kw battery storage ... DC coupled to 16 off 405watt solar panels on two arrays, SE and SW facing. 6480kwp I 'll be testing you new calculator page just as soon as it's fully released. Looks a great tool in the decision making process.
Thank you ! Great video. We will install an 8kw Solar array + a Tesla power wall 2 and backup gateway next month, so this tariff looks very interesting. But my biggest concern is actually getting Octopus to convert us over to it successfully. This is because I have previous experience of them not reading my smart meter correctly. As a transferred customer from Avro, I was on a standard flat tariff, but had a dual register meter. Octopus only billed me for the day rate readings and ignored the night usage ! It took me 6 months to get them to apply the tariff correctly by reading both registers and charging the same rate for day and night usage. This required support from the ombudsman. At least I had the confidence that when sorted it would be easy to calculate the amount owed . With flux, it will be a lot more complex ! Is there any advice as to how to prepare for this with octopus to get over to it asap? It almost feels like they may need to install a new meter ? Thanks for listening 😊
Hi Richard, sorry that you've had a painful experience getting your billing sorted out. I could imagine there would always be problems with Octopus transferring over customers from a failed provider. Some of the pertinent data (like the fact that you were on a dual register tariff) might not have been transferred. And then, retrospectively trying to get that data back from the DCC might take time. Sounds like that's all sorted now though - shame you had to go through the Ombudsman, but that's why the role is there. Flux is actually a single register tariff, so I think you'll be fine. Worth emailing hello@octopus.energy just to let them know you've have problems in the past, and could they perform a few checks post-tariff change, just to make sure everything is working fine. Good luck and all the best!
@@GaryDoesSolar thanks for your reply ! I have already emailed them, so let’s see how it goes ! To make my dual register meter work with a single all day tariff they have set me up so that the same price per unit is charged day or night. So I guess they will need to apply the variable flux rates to both registers similarly. I hope their billing systems are up for it ! Thanks again.
Hi Gary, an update .. 19 panels and power wall installed Friday. Not used the grid since Saturday am ! .. I’ve applied for Flux tonight and been immediately placed on the import tariff. Export tariff will take up to 6 weeks ! My question now is , will they retrospectively credit for any export in the meantime ? I’m worried that if I now tell my powerwall I’m on flux, it will start to import between 2 and 5am, so that it can export as much as possible later in the day ? If I’m loosing the export credit for the next six weeks , I don’t want to buy , just to export ! Any experience of their way for dealing with anything I export in next six weeks please ?
@@richardtrundle2758 Great to hear, Richard! I doubt you'll get it backdated (I didn't) but it's always worth asking because you never know! 🙂 So, for the next 6 weeks, it's all about self-consumption, and you're going to find that REALLY hard, as each day brings the prospect of more and more sunshine! Argh!! Try to use as many heavy appliances as you can when the sun is out, and if you have an EV with an intelligent charger, it will pretty much soak up all your excess.
Excellent vlog in every way. I am currently researching to prepare for transition to electric. EV in van form too expensive at present, so concentrating on ground mounted solar and battery, portable or fixed (depending location restrictions). I live in a small old cottage so I am restricted somewhat.
Unfortunately it looks like Octopus still insist on MCS certificated installation which rules out people like myself who have self installed. This seems counterproductive to the goal of reducing fossil fuel usage at peak times so hopefully common sense may prevail in future. As long as an installation has DNO approval either G98 or G99 then I don't see any reason to not accept export. My DNO has granted me 4.4kW of export capacity on my self installed Victron/Pylontech setup, and although I can export the surplus energy, I won't get paid for it. So this just incentivises me to increase battery capacity rather than supplement the grid at peak times. Interesting video Gary and very well produced as always. Thanks for sharing.
Hi @craigchamberlain, very interesting to hear that you self-installed. Do you have any more info anywhere about your experiences of how you went about doing this? Thanks
@@chaswinder Hi - I've commented on some YT videos and some forums but I've not published anything formal. I did give an overview on a forum but I'm not sure if I'm allowed to post links to other website here so I'll copy/paste the text below. Let me know if you have any questions. I installed an "ESS" (Energy Storage System) a few months back with the intention of taking advantage of cheap overnight electricity to charge them up and then releasing that energy during the day when prices are high. So, basically I have installed two 4.8kWh Pylontech US5000 batteries for a total of 9.6kWh. These are charged (and inverted) by a Victron Multiplus-II 48/5000/70-50 inverter-charger which can charge the batteries at a rate of 70A DC and can generate a continuous power output of 4.4kW and up to 9kW peak for 15 mins or so. It can also provide battery backup for my house in the event of a grid outage. To enable this I split up the loads in my house onto two new 18th edition consumer units. The primary CU takes the main meter tails in through a surge protection device and then has RCBOs for the Cooker (40A), Shower (40A), Garage/EV (40A MCB) and the Inverter (50A MCB). The output from the Inverter then feeds the secondary CU and it has all other house RCBOs including 3 ring final circuits, 3 lighting circuits, smoke alarms and boiler. I also have a transfer switch to allow me to bypass the inverter for maintenance or if it failed. The inverter also has its own TT earth rod because the regs don't allow you to rely on the DNO earth in the event of grid failure. I have an EV (2017 BMW i3) and have been on the Octopus Go Faster tariff for a few years. That allows us a 5 hour window (21:30hrs to 02:30hrs) each day when grid power is 8.25p/kWh (inc VAT) whereas it is just over 40p/kWh for the other 19 hours a day. So we charge up the EV and Pylontech batteries at the same time and then discharge the Pylontech batteries during the rest of the day so that we effectively pay 8.25p/kWh for all our electricity. We've been running this for about 6 months so far and it's been great. We use something like 9600kWh per year, 2800 of which goes into the EV. We've reduced that a bit through generally economy savings but probably still use 5000kWh/year in the house alone. That's about 13-14kWh per day which obviously is more than the 9.6kWh of battery we have. However, we have also been running the dishwasher, washing machine and drier during the 21:30hrs+ window. Also, the battery only has to last 19 of 24 hours each day. My electricity bill for last month showed that 97% of our electricity was consumed at 8.25p/kWh and the other 3% was at 40.13p/kWh. The previous month was 95% so this wasn't a one-off. Bottom line is that we are finding the 9.6kWh lasts all day most days and that's keeping 10% charge in reserve. It won't last all day if we are running all the appliances during the day and maybe baking stuff in the range oven etc. But that's unusual. I did a lot of work on the spreadsheet before committing to buy the battery system and I worked it out as a 4-5 year payback period. That involves a number of assumptions, not least is what the price of electricity will be in the coming years, but I did the calculations very conservatively rather than as an exercise in justifying a new "toy" if you know what I mean. The other thing is that Solar PV can be added to this system really easily by just connecting up strings of panels via MPPT charge controllers. MPPT stands for Maximum Power Point Tracking which basically means the voltage and current being output from the solar panels are kept within the most efficient window and can yield 99% efficiency since it's a DC to DC conversion rather than the usual DC-AC-DC conversion you get with a normal inverter. My plan is to buy 16-20 400w+ panels, probably Trina brand and fit them in time for spring. That should allow me to charge my batteries entirely from solar depending on time of year and then just use Octopus Go to top them up as needed. The payback period with the solar doesn't actually change because the extra capital costs are offset by the lower running costs almost exactly. But it gives further insulation from energy costs in future and a degree of self sufficiency. I might also buy a third battery if I find that I run out of storage during the summer months because I can always dump some energy into the EV. The Pylontech batteries have a 6000 cycle/ 15 year projected lifetime and I think they have something like a 7 year warranty which is extendable to 10 years or something. I forget the details. I bought my kit from here ( essandsolarsolutions.co.uk/products/multiplus-ii-gx-48v-3-5kva-230v-ess-bundle.html ) and would highly recommend the company. It's a small business owned by a guy called Etienne and I've had nothing but great support from him all along. His mission is to supply the DIY market because he really dislikes the whole "MCS approved" racket that has also been commented on. There is a great Victron community forum at community.victronenergy.com/ if you want to get a feel for things. The Multiplus-II is a solid piece of kit but it does make a bit of noise when running at full power so I'd advise choosing location carefully. The batteries don't work below 0C and prefer room temperature for efficiency so again choose location wisely. I can go into this more if interested.
Thanks for watching and also your comment, Craig. Yeah, I'm not sure why the MCS requirement exists for exporting on certain tariffs. I'll try to dig into this...
@@craigchamberlain Thanks so much for that extremely detailed reply Craig! For the inverter and mains aspects of the install, did you have to engage the services of an electrician to keep the DNO etc. happy, or did you manage to go entirely 'diy' ? It's this aspect of doing an install I'm particularly interested in (my own plans being to use cheap 2nd-hand solar panels with a proper type-approved grid tie inverter, which I'd want to do diy as much as possible). Many thanks
You have a very similar setup to us, 5kVA MPII and 12kWh Pylon batteries. So frustrating they dont accept it on SEG when self installed with no MCS even though the DNO are more than happy for you to sync with the network! I can appreciate the MCS need when we had FIT and no smart meters as generation was a guess and you wanted to know what was said to be installed was actually installed. Now they could easily stipulate that you need a smart meter to get SEG without MCS and that would cover them as it would only ever record actual export and can't be fiddled. That with the DNO approval would mean things are as safe and secure as with MCS but also helping the grid. I've tried to Tweet Greg Jackson on this several times but never had a response. Unfortunately it would take someone with enough visibility/followers to self install to get them to take notice.
I'm on the Octopus Tracker tariff which is regularly giving me rates of around 21-24p. With the Outgoing fixed at 15p it doesn't seem worth risking the higher day rates of Flux. If the tracker rates go up it might be worth switching though.
@@GaryDoesSolar they've actually just limited signups to 50 a day now because it was so popular and there's apparently a 6 month waiting list unfortunately. Biggest saving over the winter has been gas though which has averaged about 6p / kWh. Today's rate is only 4.97p - less than half the EPG rate.
Gary, have looked into V2H, V2G, V2L and V2X? I'm wondering if that would be a viable solution for a home battery instead of the ones you've shown in your videos.
Hi Paul, it's on my list - and I'd be focusing on V2G with a little but of V2H... Just waiting for support for those technologies to get a little more traction first...
I can't provide you with advice (given liability considerations) but I can say what I might do. And in fact, I'm on Flux at the moment and have been so since March - it has been great and I've made money almost every month. As winter approaches though, with less solar generation and consequently, less solar excess to export, Flux becomes less beneficial. I don't have an EV otherwise I'd be straight onto Intelligent Octopus Go (and if my situation didn't qualify, then the basic Octopus Go tariff). So, I'm actually eyeing up Octopus Agile... Hope this helps, James.
Hello Gary I am enjoying your videos, I live in Ireland, unfortunately we do not have octopus, but we do have some cheap rates. Can you charge two batterys at the same time.Thank you Tom.
Hi Tom, great to hear that you're enjoying my videos - I'll keep them coming. Octopus is expanding all the time and I'm sure it won't be long before they're present where you live. In the meantime though, keep an eye out on all the providers you do have there - they're starting to wake up to the needs of solar, battery and EV owners and are building tariffs to suit... Yes, you should be able to charge two batteries at the same time, provided they are controlled by the same string inverter. The inverter will ensure the batteries remain at roughly the same level of charge each.
Hi Gary, What have you heard about Octopus bringing out a new "Intelligent Octopus Flux" tariff? It seems to be restricted to owners of GivEnergy batteries, has the same import and export rates, no cheap flex rate and I think that Octopus would control the importing and exporting of one's battery.
Hi Nick, so, it's still all quite new, and details are sparse. It's only open to GivEnergy battery owners initially, but that is expected to expand to other brands over time. The new tariff is currently being trialled with a subset of customers, to iron out any problems etc. I'll be making a video on the tariff shortly...
Interesting video, but more info on export tariffs would have been helpful. The technology is very capable of duty-cycling its energy collection/storage and dissipation elements but economic return on capital employed is ultimately determined by the values of feed-in and feed-out tariffs. In the absence of long term government regulation the wild west UK energy markets will continue along its chaotic path.
Thanks for commenting - yeah, like you, I believe export tariffs are a key catalyst for driving the home solar market. I do plan on covering more on these in future videos.
Hi Gary I just had a look at your spreadsheet- very neat - I note that if I remove the FD switch to indicate that battery not dumping then the battery remains fully charged through the day from solar, whereas it would show greater savings if the battery was discharging through the day and more solar was going to the grid as the price gain for solar export is greater than the cost of charging?
Hi Gary, great content and really helpful spreadsheet. I have spotted an error, Once the battery is fully charged in the Off-Peak period, the spreadsheet still shows grid import for the full charging rate even though it wouldn't be charging once full. Set Battery size to 5kWh to see what I mean.
Thanks for the brilliant explanation of flux. We are thinking of changing from economy 7 to flux. Do you have a table to work out how long it will take to pay them off? And which tariff is best for me. Thanks
You're very welcome, Dawn :-) So, I am working on a utility at the moment that can give you a view of how well your setup will perform with Flux (or other tariffs). I'll post this link after this comment, but in case UA-cam automatically deletes links, just look in the video description for it. You could also take a look at another video I did a while back on calculating your payback period. Again, I'll try to post the link below.
Really enjoying the videos. My install was commissioned in June after a 1 year wait. 4.4KW (12 x 370w) panels, .6 KW Giv Hybrid Inv (gen1), and Giv 9.5KW battery. The Inv limits the battery charge rate and the supply to the house to 2.6KW/h, which is quite limiting. You are higher at 3.6KW/h, but I think 2.6 is too limiting for adding another battery to my system. I think however adding a GivEnergy all in one would work for me, as it connects directly to consumer unit, can be charged from grid or solar, and gives 6KW/h charge/discharge and think this would be on top of my 2.6 from the inverter. However, I think it may need a G99 application, and pricing may be high just now as only released - would be interested in your thoughts on GivAllInOne.
Also already on Flux, but thinking Agile might be better for me in winter - when not likely to export, and maybe take advantage of plunge pricing to charge battery, and charge cheaply through night. 3 hrs on flux with 2.6 charge rate I cannot fully charge battery.
Hi George, thanks for your kind words on the videos :-) And yes, you're right, the charge/discharging rates on GE products are not great. But adding a new battery/inverter as AC-coupled will increase that. I'll be covering this and other things in a follow-up video I'm making on batteries...
Hi Gary, loving your videos, thank you! Your calculator spreadsheet seems potentially useful but as you acknowledge in your video, it doesn't yet work for Octopus Flux as it only accepts 2 of the 6 figures from an Octopus Flux quote. Personally I'm initially looking at a storage only installation (13kW battery + 3.68kW hybrid inverter) to take advantage of the difference between the Flux import and Peak export rates (with the hybrid inverter to support potential future investment in solar) so I'm looking to model that configuration to see how it plays out over time and whether it makes financial sense. So here's hoping that you will be updating your spreadsheet so that it has inputs for all 6 of the rates found in an Octopus Flux quote so that the spreadsheet fully takes them all into account. It's also missing DoD (usually 90%, but does vary) and for future proofing should also allow specifying the number of Flux and Peak hours. It might be better to allow the user to specify the import & export rates for each hour of the day, allowing usage not only for Octopus Flux but also any other tariff where the rates vary by hour, which would work for future tariffs which could potentially have more than 3 different sets of rates.
Hi Marcus, thanks for the great feedback! :-) Now, the spreadsheet is already populated with the pricing for all six tariff periods for Octopus Flux (normal, off-peak, peak) in fact. Check the values in columns N and R - you should see the different prices depending on the time. Each hour can have its own price (for both import and export). Is that what you were referring to, or do I need to add something else to the spreadsheet? In any case, I'm working on a web app version, which is much easier to use, and if you'd like to try it out before I release, please email me on "me" followed by an at symbol, then my channel name (all one word) and finally dot com and I'll reply with a link.
Really good video. For me this model works well Spring, Summer, Autumn but the Winter would cost a fortune with not much solar and only night charge time of 3 hours, this is very restrictive for an electric only house. Fair play to Octopus for trying out different tariff models. Why aren't the other electricity providers trialing these tariffs? Also need the UK electricity tariffs to be much more stable in order to get consumers to invest. I'm on Octopus Go Faster with 11KWh of batteries, works brilliantly.
Thanks Phil - yeah, the other providers seem to be asleep at the wheel on tariffs (meaning, their billing infrastructure isn't set up for this, and it's too complex/expensive to upgrade, maybe). I don't think you sign up to Go Faster any more, so hopefully, you've a while to run with it yet... :-)
@@GaryDoesSolar yeh I’ve got until August on GO Faster. We are lucky to own a Tesla so I think I can move on to Intelligent tariff. Your video was really interesting, just looking at the rates on the Flux tariff I assumed it would be no good for me. However it would be really good except for Winter. Hopefully all tariffs will come down before the next Winter!
This looks good. So basically you are saying that this combination of solar, battery and energy tariff is making money for you. Could this be an option for everyone? Also outside of Oxford, the UK? How is the situation in Ireland, Holland, Germany, Poland, Finland and Greece? Gibraltar, Malta, the Falklands???
Thanks for taking the time to watch, Freek. So, in the UK, I would say there is the opportunity to make money using the Flux tariff. In other countries, it depends on whether the energy providers in those countries off similar tariffs. If they do, then the same opportunity applies.
That was a nice, clear presentation. When I discuss solar and battery installations with friends and family, instead of 'pay back time' I try to emphasize that they should think of it as a dividend on a capital investment - and how much better and more reliable a return they get compared with stock and shares or, worse, money sitting in the bank. Nowadays, £4k will get you a solar PV system which will generate (at today's high rates) about $500 per year in savings - that's a 12.5% return on capital. On batteries, the equation is not quite so good. I point out that there is a capital cost to charging batteries - they wear out. A typical battery can be charged 4500 times - still 12.3 years at one charge/discharge a day - but if you spend £5000 on batteries you're likely to get about 12kWhr of storage. After you've done the sums, this means that every time you charge the batteries, your capital cost is about 10p per kWhr. So if you are using that battery energy to offset paying 34p per kWhr then your net saving is 24p per kWhr over the long term. If you are using the grid to charge the batteries (rather than solar) then you have to add that cost on to the 10p capital cost. So 20.24p + 10p is your actual cost per kWh and then you're offsetting this against 33.73p regular rate - so that's only 3.49p per kWh saving (net long term). What we need are cheaper batteries(!) - cheaper per kWh charge/discharge cycle - it doesn't actually matter how long they last: a battery that only charges 450 times but costs £500 for 12kWhr is exactly the same as the expensive, long life battery.
Hi Gary , I have been with Octopus for sometime now, i have a 4 kw solar panel system and 7.8 kw of battery storage , currrently on Octopus outgoing using Econ.7. I have expressed interest with Octopus Fliux but as yet undecided. The seg rates look attractive however the import rates at peak times are quite high and thats a bit of an issue however during the summer months could be well wortth it and maybe switch back arouind October time. Seems like no brainer but is there a catch. By the way your videos are great .
Thanks for the kind words. I’m thinking that because you’ve got a good ratio of your battery vs array size, that you should be able to charge enough to get you over the peak period, more than half of the time? And any costs you do incur over the peak period will be offset by some of your export revenue? And depending on your battery, you might be able to get it to hold charge until the peak period?
Finally someone who explains all this confusing tariff charges in easy to understand language and graphics.... looking forward to more content...!
Hi Bob - thanks for this excellent feedback. Exactly what I’d set out to do, so great to hear I’m adding useful value 😀👍🏻
I've been with Octopus for about two and a half years but I changed to FLUX just over 2 weeks ago.
The results are FANTASTIC.
I have a 5.6kW array of panels and battery storage of 11.6kWh. My house is 100% electric - no gas.
The house has all the usual domestic appliances - two large freezers and two fridges, two electric ovens and an induction hob, washing machine, tumble dryer, two large screen tv's, a hot tub and a charge point for my EV. So our daily load is significant. I run an air source heat pump for heating and hot water.
Since changing to FLUX I have only used mains power for three hours a day - during the low cost FLUX cheap period between 2am and 5am.
So my batteries get charged during the day from the sun when it's not too cloudy and from the mains during the cheap rate period.
Each day I've used NO MAINS ELECTRIC between 5:01 am and 2:00 am the next day - it's all come from the batteries.
We haven't even needed to set timers to run stuff in the cheap period, except for charging the EV.
On three days it's been fairly cloudy all day and on four days it's been sunny
So I've used 139.9 kWh at my cheap rate of 19.4p (£27.14) and exported 29.22 kWh at 34.76p (£10.15).
So my total outlay including running my house, a hot tub, an air source heat pump and my EV has been £16.99 for the week.
The EV has used about 82kWh, 47kWh from the batteries or solar and 35kWh from the mains at 19.4p
So the car has cost me £6.79 to do 220 miles because most of the power was from the sun (via the house battery) and the rest from cheap rate power. If I was running my pervious car which did 50mpg on diesel that would have been around £30.00
My Octopus rates are as follows (they vary depending where you are in the UK)
Cheap rate - 19.4p (import) & 8.44p (export)
Standard rate - 32.4p and 21.4p
Peak rate - 45.26p and 34.76p
I think, looking at the temperatures and the amount of sun etc over the last week this will be a fairly average week for me over the year. so I can infer a total energy bill of around £880 a year or £73 a month.
These are rough figures so please don't nit-pick - I'm just trying to give an idea of how good this tariff is likely to be. I hope it hasn't been too boring or complicated.
Thanks for the video Gary - clear and easy to watch. Keep them coming
Thanks for sharing the details around your experience with Flux, Scott. Amazing results and I'm sure this will help persuade people who are not sure about Flux, to give it a go! Thanks also of the kind words about my videos :-)
how did you get that export rate?
Thanks for your statistical info, gives me confidence. One query is I've contacted Octopus by email concerned about my feed in tariff standing, I want to migrate the same rate from my recent move from SSE. Octopus have not replied yet after a week, so how does one communicate if I want to change my plan to Octopus Flux, or a plan that's suitable for my system??
I have much the same size system ,thou my battery is slightly smaller.. As I live alone I use very little power,so my battery is in use all the time ,I import around .25kwh a day and in the last month consumed 115kwh while exporting 138kwh via solar... I do not run an EV (in my case it just does not make financial sense to purchase a £30 000 car when my old car is running so well,) Hopefully by the end of the yearly solar season (which I think of at the end of Nov ,when I start cooking on gas ) I hope to have at least £200 in credit with Octopus , and with that cedit use to finance to dark days of winter,which is around 75days or back to cooking electric middle to late Feb....... The thing I am looking at is this, ,,Octopus standing charge for me is 42p aday,,(I think) per year thats £153 and thats just electric I think the gas is another £100 ayear, so £250 ayear down the swanny for what!!!!! I am considering switching to Utilta for my imported energy and keeping Octopus for my export.. Utilta has no standing charge and is a prepaid energy,,so in theroy I could buy and save credit with them or save the cash myself and just buy as needed..The price of there energy is more expensive but even so .I think it could work.... Regarding using your battery to store then export ,,, in my case I have to wish to do that,,I am 67 and want my battery to last my lifetime.. so I do not want too work it that hard...Treat your battery like a baby care for it and hopefully it will last ,,,regards
@@ExplodingPiggyOctopus.
Many thanks for your informative video. I have joined octopus on the flux tarrif using your link to get both of us the £50 reward. Even in March I am powering numerous appliances and exporting up to 5KWh per day. So far I have not programmed my solar/battery system to download during the three hour cheap period but will do so soon
Many thanks for your informative videos I have subscribed
Hi Philip, you're most welcome - and thank you so much for using my referral code - that helps me an incredible amount :-)
Btw, I'm working on a web app version of the utility - it's still quite early but it's shaping up nicely and also fully functional. If you'd like to try it, please send me an email to "me" followed by an at symbol, then my channel name (all one word) and finally dot com, and I'll reply with a link to it.
Brilliant explanation of what’s available. I feel we’re in a ‘coming of age’ period for how and when we consume power and it’s positive impact on the grid. Driven by Octopus where the enablers are solar, home batteries and EV’s. Exciting times.
I have an EV and am still seriously considering a move to Flux from Intelligent. It helps that we have a SW facing roof where this lends itself to the peak period for export.
Great videos Gary. Looking forward to the rest of the series.
Thanks Jonathan - I totally agree. We're just getting started, I reckon :-) And yes, I was going to mention in the video that any roof with a partial/full West-facing aspect, would be very good for Flux (but I forgot!) :-)
Just had Solar installed and was looking for info on Tariffs, this is an excellent video made by a great presenter and an easy to understand description throughout
Thanks Geoff - it’s great to get feedback like this, as it means I’m on the right track 👍🏻😀
Thanks Gary you help me educate my customers
Hi Aaron - thank you so much for the super thanks - very kind of you, and I'm very happy to have been able to help you. I'll keep the videos coming... :-)
Thank you for this excellent breakdown
You're very welcome - glad it was useful to you :-)
Keep on doing what your doing Gary. We all need people like yourself. My battery system on a fully south facing roof went live last Friday. Aug 18. I have sat & watched your vids in a really serious manner & treated it all like doing a O/U degree. You pack a lot of info into your tutorials so by the same measure you put a lot of effort into what we see. Thank you. I will stand by my product selection "Cos its done now". My next minefield to cross is the Tariff affair. For next few months I will stay where I am just so I get to see actual savings. My point of reference. You manage to make a very complex & outwardly very boring subject interesting. Top man. Well done you.
Hi Rich, your comment has made my day - thank you so much for sharing! And good luck in your tariff analysis - it seems we're all spoilt for choice with smart tariffs these days (at least in the UK)...
Thank you for a very useful video. I've just had 10 4.5kw panels and a 9.5 kw Givenergy battery fitted and managed to switch from Shell to Octopus with a new smart meter fitted yesterday. Flux sounds great however we have a 12kw electric boiler and have a high consumption rate especially in winter.
Ican see I'm going to need to study your chart carefully before I choose Flux or Agile. Thanks again
Hi Kevin, my pleasure to provide you with that - and now, instead of the spreadsheets, you can use my free online utility, which is easier to use. Try it here: garydoessolar.com/utilities/dailymodellingutility/ Good luck with whatever tariff you finally select! :-)
I have solar, battery and an EV, I moved to flux from the flexible tariff - so far so good :)
Great stuff, Tony - hope you can achieve good savings (and maybe even a little profit) :-)
Great Powerpoint skills *and* impressive Excel formula wrangling? Your skills have no limits Gary! :)
You're far too kind, Chas. But wait till you see my programming skills :-)
(Actually, I used to be very good at that, but the world is changing fast and I can't keep up with it!)
At 1:15 you mention the duck curve as being the energy demand. As far as I know the duck curve is related to the solar production in relation to the demand during the day; a completely different graph than only the demand curve.
You’re right - I made a mistake, which is corrected in the video description 👍🏻 I managed to use the phrase correctly in this video though 🤣 ua-cam.com/video/WpkLX0GTSE4/v-deo.html
Thanks for you reply @GaryDoesSolar, I’ve watched most of your recent videos. I’m from The Netherlands, here we have fixed, day/night (07:00 - 21:00) or dynamic (hourly, day in advance) tariffs. I find it very challenging to determine what battery installation to get and value your views 👍
@@SanneHoekstra Certainly worth considering a battery capacity that is large enough to cover your typical daily usage. That way, you can fully charge it during the off-peak period (fixed day/night tariff) or during the cheapest hourly slots (dynamic) and it'll see you through the remainder of the day...
I really commend you for providing this insight! Unfortunately this is not translatable to the Dutch energy prices. In the Netherlands we have the “salderings regeling” that meant that you can deduct every solar generated energy from your bill (during the contract period, usually 1 year). Effectively you can use the grid as a battery from a price perspective. This is not durable obviously, you can economically use the grid as a seasonal battery, while there is no seasonal energetic storage in place. With the politics lagging behind the energy companies are starting to change for yearly returned energy by households. Just to summarize, it’s a mess….
I agree with your view. Having at least 100% of your daily usage in battery available will turn out to be profitable (economically and ecologically) in the long term. Politics and price have to follow reality in the long term… 👍
*** NOTES SINCE PUBLICATION ***
1. Oops - it was pointed out to me that the "duck curve" is actually to do with solar production, not demand (sorry about that).
2. The Octopus Eco7 rates are slightly different than in the video - the off-peak rate of Eco7 is actually higher than Go.
3. I've been told that it's possible to have Octopus Go and and also to be signed up to Scottish Power's SEG export at 12p (with no extra standing charge). So that makes Go even better! 🙂
4. Here is a link to the utility I covered in the video - please feel free to use, but as it could contain bugs, no warranty is provided. Please use at your own risk: www.garydoessolar.com/utilities/fluxcalculator/index.html If anyone finds a bug, let me know and I'll try to fix. I'd also be happy to people to work on this, improving it. If you message me with a copy of your new version, I'll add it to the website, of course crediting you. 🙂
I've been asked how you can support me in my work if you're already on Octopus. I'm happy that you're getting something from my videos, but you can always buy me a "coffee" using this link: www.buymeacoffee.com/GaryDoesSolar - thank you! 🙂
Thanks Gary this will be really helpful for me. I'm currently getting quotes for different size arrays and batteries and was looking at how best to use the energy it'll create.
Glad I found this video. Convinced me to increase my battery size prior to agreeing installation.
I will look to increase my battery caoacity in future by adding additional batteries in parallel.
Seems like basically the objective financial answer for everybody is get the biggest battery you can afford at first, it will pay for itself using flux import/peak export.
Cheers Martin - yeah, and with battery prices coming down all the time, it's a really good investment. Not sure if you saw this video I made yet, talking about that, but here's the link: ua-cam.com/video/3vwDrfuXyik/v-deo.html
Great video for Octopus Flux well explained, i signed up yesterday at last some decent export rates, keep up the great work
Thanks Mark - really great to hear you liked it! :-)
Just to let you know, I've just released the next video in the series - this time on Agile...
I’ve got a GivEnergy 3.6kw inverter this charges at 2.5kw max. If I was thinking of installing solar/battery I’d get as big a battery that I could afford and a 5kw inverter. The inverter is the limiting factor.
Excellent idea for the series Gary, thanks.
Thanks Ian - yeah, I have the 5kW version of that, but the charge rate is limited to 3.6kW - sometime's I'm pulling 6kW so a bit of a problem :-/
Will think about a video looking into these rates in more detail... thanks
Here in South Australia the off-peak is 10am to 3pm when all the rooftop solar swamps the grid. On some days, rooftop solar output exceeds demand and some inverters have to be turned off to reduce generation.
On the wholesale market, electricity is often negatively priced between 10 and 3.
Our problem is a lack of cheap power during peak and overnight.
Hi Rob, thanks for this information. Sounds like a big battery is perfect for that kind of situation, yeah?
@@GaryDoesSolar for people on wholesale (almost nobody) a battery makes sense. On normal retail plans they are too expensive and will never payback the investment.
@@robhaitch5544 Ok, I see.
I have PV/Battery. Solax. On Flux. During the darker months I charge my batteries during the off peak hours. I then let my batteries discharge from 5am. I then force them to "top up" for 2 hours prior to the higher rate. This ensures I am keeping my batteries full at all times and exporting the maximum to the grid; and that my batteries are depleted during the higher rate hours. I have a 9KW battery systerm but wish I had gone for double that size as my family use a lot of power in the evening. If you can afford it, go big on battery stroage.
Sounds advice! I just wish battery prices would come down quicker than they are - would allow people to consider those larger batteries, as you say.
Super work, well done. One strange thing: I'm on Octopus Go though we do NOT have an EV. We have up to 5kW from solar and a Tesla Powerwall 2. It looks like Flux should be the way to go, but we are very high energy users (I run a business from home, computers and other equipment run most of the time), so outside the peak of summer our battery will often be nearly flat by 4pm. How did we get onto Go without an EV? We were ported across from the Bulb EV tariff which didn't require an EV.
Thank you! Yeah, Flux is a pretty attractive tariff :-) IU've made available a web app now for people to see if Flux is right for them: garydoessolar.com/utilities/dailymodellingutility/
First class video again Gary, many thanks. I have 9 KW of PV 2 x 8.2 KW Givenergy batteries + an EV and a PHEV. Being on the early - high- FiT the calculation for me is a trade off between which tariff and the FiT. Will be investigating Octopus as my tie in with EDF expires soon. Having an EV tariff has enabled me to charge the batteries through the dark winter months - its the way to go.
Hi Alan, that's an impressive setup - I'm jealous! And being on FiT is just a dream as well. Your early investment must be paying off incredibly well :-) As you can probably tell, I love everything about Octopus Energy - they're just doing things right. I'm wedded to the mobile industry with my career, but if I wasn't (and who knows what might happen in the future), I'd be interested in working for those guys!
Alan, I have a similar set up to you (17.5 storage and on FIT) but without the PHEV. if you can't move to Octopus Intelligent (they will only deal with certain cars and EV Chargers, I have Merc and Zappi, neither of which are compatible) then look at British Gas Electric Driver. their price is the same as Octopus Go but you get a 5 hour window to charge instead of 4. For me that means I can fully charge the batteries every night in winter and get 35kWh into the car.
Marvellous! I have been saying we need a big spreadsheet to understand all the variables, but I was daunted at the prospect. I will check out all your videos as the first one I found was packed with useful information.
Thanks Rob - great that you’re getting a lot of value from my work 😀👍🏻
Great video Gary. I'm switching tonight. Just need to convince my wife to eat her tea at 2am now! Subbed and Liked!
That made me laugh, Nic. Good luck, and please do let me know how it all goes :-)
Great video, and a superb spreadsheet! Just the kind of thing I wanted to try to do but, seeing yours saved me SO MUCH effort, and made me realise my skills probably werent' good enough anyway! :) Donation on its way!
Hi Chris, thanks for taking the time to comment and also for the donation! :-)
I'm hoping to improve on the utilities over time!
Hi, I have just found your channel and find interesting, I wish there had been a similar amount of detail when we got solar panels 7 years ago. One point to note is that for people who are still on the uk gov FIT scheme, the PV export price we get is ~5p per kwh (it depend on when you entered the scheme) which is significantly less than the current octopus rate (~15p per kwh) BUT I get paid based on a "deemed" export of 50% of my generation when in fact we only export about 10% of our generation, so this alters the economics.
And yes I have a spreadsheet that calculations this !
Hi Carol, thanks for sharing your experiences with FiT. It was a great scheme, and kick started consumer solar for the UK. Not available to anyone today, but Tariffs like Flux provide something close(ish) :-)
Gary, really clear content, formalised what i thought i understood. Friend and i decided to buy identical systems. Ordering next week 16x400W, GivEnergy 5.0 inverter & 9.5kW battery. For 2 systems supplier provides scaffolding FOC. 👍
This sounds like the system we would like. Would you mind sharing the ballpack of what you are paying, please?
@Chelle Coulson a touch under £14k. That includes discount for buying 2 systems and the company offered me £250 introduction free for the 2nd customer, which i further discounted £125 each system 🤣
@@nicflanagan6662 Thank you. I'm getting quoted £3k more than that, which is taking the mick I think. Enjoy your new system!
@Chelle Coulson just for info, we both decided that we wanted to buy/install through a local company, rather than a web based entity. The company we will order from mentioned that they are frequently approached by said entity to quote to install their system or rectify. We're in Dorset, not sure if that makes any difference 🤔
That's great to hear, Nic! All the best with your installation, and thanks for the taking the time to watch my videos :-)
Hi, great video, at moment trying to decide whether to increase battery storage from just 5kwh. Watching with interest as at moment cannot financially justify increase. Thanks
Hi Laurence, that's so great to hear - thank you! :-)
Great video thanks Gary. We got solar and tesla powerwall last September and were able to get onto the Octopus Tesla Energy plan which is soooo good from a money point of view as it's fully symmetrical. On sunny days we make a really large profit on energy exported.
However we got a notification when they launched Flux that this plan was now discontinued and we'll be forced to change in September. It's quite unfortunate because the tariff was one of the main reasons we decided to shell out for solar, the payback was going to be around 10-15 years but now with flux I think we may be out of pocket with the solar. However, at least we're helping the grid and the environment so I guess it's still worth it :)
Hi Matt - thanks for the kind words :-)
Yeah, a shame they're stopping the Tesla Energy Plan - I guess you've had a good run at it. You might surprise yourself with Flux though, although having an EV does make it a little less lucrative. Might be worth you watching this video, where Anthony (who also has a Tesla) carries out an in-depth financial analysis of different Octopus tariffs: ua-cam.com/video/kWoBzds07Y0/v-deo.html
Gary, again your video is superb. I cant imagine how long it takes to put this together and edit. Thank you, its really helpful for me.
Thanks Scott - yeah, it does take quite a few hours, but I'd like to think I'm getting a bit quicker at it (I'm sure the reality is I'm not though - lol). I'll keep the videos coming...
Thanks Gary, I've got a 5kw Solis inverter & 14 375W PV panels,a myenergi Eddi for my Hot Water (instead of using my Oil Boiler to heat the water) and a Solax X1-Fit inverter and 3, 5kw Solax batteries for now I'm going to stay on Octopus Agile and Outgoing Agile Octopus for my export having only had the system fully installed this winter and waiting forever for the DNO permission I'm not actually sure what my Leccy Bill will be in Summer but so far I'm very pleased with my system, I'll keep watching your Channel to see how you get on with Octopus Flux,hopefully it's the right Tariff for your family 🙏
Thanks Ian - much appreciated, and hope you get DNO approval very soon!
@GaryDoesSolar DNO all through Gary,took ages though, the system seams very by the Government to grant permissions
Oh, that’s good! Mine took more than 5 months! Madness
Gary, your video was so informative. I am about to have solar and batteries installed and I think Flux will be ideal for me. Thanks for your hard work.
Hi there Jean - good luck with your installation, and all the best with your Flux tariff - I think it's a great one! My pleasure to bring you videos like this :-)
Outstanding thank you so much for the video and for your utility. Extremely valuable!
Hi Jon, my pleasure! And very happy to help you out. I'm in the middle of developing a coded version of the spreadsheet, as the spreadsheet is too unwieldy now. Will release the link for it shortly :-)
Super helpful video Gary. Thank you.
Our Solar PV system went live just 3 weeks ago and is already reducing our grid consumption by almost 70% (and that in a not-so-sunny Dumfries!)
I am already thinking of adding a second battery to reduce our exports to grid and the Octopus Flux tariff will make a second battery even more financially viable. The only (slight) stumbling block is that I now need to really get my head around how to correctly set up my Solis invertor to deal with forced imports and exports!
Great news about your grid consumption - and hopefully a lot more sunshine over the coming months! Yeah, I'm hearing that quite a few brands of battery don't handle forced export very well, but forced import should be possible, given that off-peak rates have been around longer than solar batteries. Good luck in your research on Solis, and thanks for your kind words about my video :-)
Great video Gary. Looking forward to your new utility (found the last one very helpful). My rough calculations show Flux is absolutely the way to go for us. Our system doesn’t allow force discharge of the battery, but even without that I think it will be a real winner.
Thanks, Stephen. Yeah, I guess all the batteries are different. But at least you can hopefully cover your load with the battery during the peak period, and the sun should still be around to provide some profitable export. :-)
Not sure the short charging period will work on a smaller system , 3.6 kw inverter and 4kwp panels , during the winter with much reduced solar input. I think we would need to switch to a better charging period for this time.
@@albennett9947 yeah, good point. It’s all fine in the summer, but winter is a different story…
@@GaryDoesSolar also the other thing to consider is battery temperature.
I went through this winter and on a couple of nights my batteries went under 5c (4.5c) and I noticed thier charge rate during eco7 dropped sharply to just 10A per battery (about 500watts) i have 4 batteries (20kwh) but a drop in charge rate to 2kwh would take 9 hours to charge from the maximum discharge level of 90% (a battery SOC of 10%)
Not enough time to charge during economy7 and definitely not enough to charge during 4 hour octopus go or 3 hour octopus flux.
Conversely at 13c, my batteries can charge at their full sustained 0.5c rate 50A per battery (2.7kw) meaning 10.8kw which is beyond my inverter charge rate.
The key note from this, most batteries are installed in a loft or garage.... uninsulated... so exposed to night cold.
Its something to consider as you may mot be able to charge fast enough in tbe charging window.
@@davespages Crikey - so many variables to consider, eh? I've made a note for any follow up videos I do on forced charging - thanks for highlighting!
Great video - thanks. We’re currently on Go as we have an EV. I’m considering solar and batteries but it’s so difficult now to work out break even etc because of tariffs like this! Hurts my head!
You're very welcome :-)
And now, you know how I felt trying to build a calculator utility - haha!
Thanks so much, I had my 4.2kw/h solar/batteries (12kw) installed in Oct 22 and as yet have not looked at the export but whilst I am away on holiday monitoring my battery charging/export of energy. I have just filled in the SEG forms with octopus and currently on Octo Go Tarrif with the 7.5p import cost 12.30-0430. using this time to fill batteries but from about 10am I am exporting as the batteries are full.
This is excellent modelling but I still need to get head around numbers, and from this video best I stay on my Go until September when it expires, although I am going to generate quite a lot of energy - will fill 80% on battery and charge my Mini via Zappi..
Hi Tony, you're very welcome. I've not long released a web version of the utility that you might like to try as well: garydoessolar.com/utilities/dailymodellingutility/
Thanks for this video Gary and for your work in the spreadsheet.
This couldn’t have come at a better time for me as this week we have had PV + batteries installed and I am just awaiting the paperwork that will allow me to switch to Flux.
You’re very welcome, Neil. Thanks for the kind words. And good luck with everything 👍🏻 😀
Hi, lovely video as always, thank you 🙂. I have solar and battery, the GE AIO and am moving to Octopus Flux. I want to automate my system to achieve the following...
1: 2am to 5am - charger to say 100% (the low-cost period)
2: 5am to 4pm - use solar plus battery but keeping sufficient charge to cover the peak period requirement. This is where it would be great if I could set the battery to not fall below say 50%, but only between these times.
3: 4pm to 7pm - use battery only to avoid the high peak rate period.
4: 7pm to 2am the following day - continue to use battery down to the reserve level.
The above cycle to repeat every day without any input from the user, must be a set once and forget.
I can achieve quite a lot of this in the GE portal but not all of it (do need to dive into the Remote Control settings).
Have you any suggestions?
Thanks
Thanks for the great feedback! :-) Worth also watching this video I made on how to get the best from tariffs like Octopus Flux - could give you different ideas: ua-cam.com/video/dGpsN8-1Fx4/v-deo.html
For some information on how to program your GE settings, this video might be good: ua-cam.com/video/DDDd_j8O5s4/v-deo.html
A nice explanation on the Flux tariff options.. I had a look are your spreadsheet, but at the moment it doesn't really manage to cater for the setup I have in place. I have 7.5kw of generation, 7.5kwh of battery, and an inverter that can push about 3.6kw to charge. I have another inverter that can push the excess solar to the grid when the batteries are charging at capacity. This is all getting a bit complex for Excel formulae... What I need to do is pull down the raw information from the Invertor and generation logs... This will tell me the flow power to / from the grid (AC side) and the flow through the invertor (DC side and conversion to home side AC)... Those two curves on a daily pattern tell me my actual usage stats, and I can code that to calculate the costs, and allow for the usage of the Flux tariff to calculate what i would have got from it for a given period...
At a gut feel though, I think that this tariff is pretty good for a house with solar and battery (though I question if that's essential) but the reduced low rate period, (3 hrs) and higher cost of that minimum period (compared to cheapest EV charging options), basically mean that this is not a tariff maximising benefits for a home with an EV that needs a lot of home charging. It might be ok for a low - medium useage of EV's..
Hi Andrew, yeah - that's quite a complex setup. You're right though, the spreadsheet is getting out of hand, so I'm currently coding up a webpage to replace it... So far, it's not looking too bad.
I agree with your thoughts on Flux.
Excellent video. Cleared up many questions for me. Thanks.
Thanks Tarquin - very happy to have been of help to you! 😀
Thanks for the vlog, just subscribed. I must admit the Flex tariff doesn’t really entice me so I guess I’ll have to buy an old cheap EV as a third car to get on the Go tariff.
Thanks for subscribing Philip :-) Haha, that could be a good strategy. I'm getting an EV charger fitted this week, but no EV yet(!) - I'll need to wait until prices come down...
@@GaryDoesSolar I have a legacy 2.2kW array on a 2011 FIT plus I've just added a 6.5kW array both are on a south facing roof. As you, I have a GE 5.0 Hy plus two GE9.5kW batteries on the new array. Interestingly the 2.2kW array contributes to charging the batteries which I wasn't expecting. The DNO capped my export at 4kWh so no real incentive to export, DNO's don't seem to have the infrastructure to have a truly distributed local solar and battery system and the Government don't issue any targets to the DNO's to strengthen the system
@@Flood51 Your two arrays sound ok. And you'll have had an excellent return on your FiT over the years, I'm guessing? I'm capped at 5kWh so only just above you, and I reckon that over the longer term, it could be good. My array is 7kWp and with the two 9.5kW batteries and Flux, my numbers tell me that I could potentially earn £4/day (including all my normal usage covered). It seems too good to be true so I'm checking my utility hasn't got some major bug in it!! 🤣I agree with you about the DNOs - it's crazy that we seem to know what's required, but those in a position of power do not... 🤷♀
Great video Gary. Brilliantly explained! 👍 I will be sure to make use of the tool when it is released as well.
No worries, Dan. How are you finding the world of being a UA-camr? It's quite involved, yeah? I'll release the utility very soon, just a couple of things to tidy up - it'll have a massive disclaimer on it too, as I'm sure there will still be bugs! :-)
@@GaryDoesSolar Very involved but I’m really enjoying it! Hoping to get another one out this weekend. Definitely appeals to my creative side, although I need to get the production quality up a lot I think. What do you use for editing?
@@DanEVSolar7 I used to use iMovie, which is ok, but I now use Final Cut Pro, which is really powerful, and relatively easy to use (lots of options and controls, which are quite scary in the beginning though!). All my graphics and animations are PowerPoint, would you believe. Amateur, but they come out not too bad. I think I need a better microphone though...
Excellent video and web utility, THANKS!
One question on the utility: when modelling an Autumn quarter using a max average array power generation of 2.4kWp with a 9.6kWh battery, using a 3.8kW inverter produces a higher daily profit figure than using a 5kW inverter. Would you expect this?
Just at the quote stage for installation and trying to assess whether the extra 1.2kW and a 12 week delay for DNO approval is worthwhile.
Thanks for the very kind words, Ray :-)
Now, on the face of it, I would not expect a lower-powered inverter to result in a greater profit for the day. I just tried those numbers here and there is no difference in profit (as the solar generation doesn't get near even the lower inverter limit). Could you try with the latest version of the utility please and let me know... thanks!
Just modelled the same numbers in the new version and clearly a better result with the 5kw inverter as one would expect.
The new version looks great BTW. I see that you now don't have to calculate the maximum achievable array output by quarter. Is this now included within the utility based on array orientation entered under the Solar Array Performance box?
On that point, my planned array will achieve a total of 6kWp but with 4kWp from the directly south facing roof and 2kWp from the directly east facing roof.
How is is best to model that performance in the utility please?
Many thanks Gary!
@@rayscogings3700 Hi Ray, great to hear that the utility is working for you! Now, yeah - modelling two arrays on different orientations is actually quite tricky. Currently, the solar model is only optimal for a single South-facing array, but it's something I'm thinking about for a more powerful utility down the line.
Just signed up to octopus and used your referral code 👍
Hi Matt, thank you 🙏 that means a great deal to me! I’ll keep the videos coming 😀😀😀
Very good presentation. This new tariff does seem very attractive. Thanks
Thanks for the great feedback! :-)
Brilliant work Gary .
Thanks Keith :-)
Thanks
That is so very kind of you, flyingmedic! Really appreciate the super thanks :-) All the best!
Hi Gary, thanks for taking the time to explain the electricity tariffs, I just signed up to Octopus Flux (used your referral code) after installing a bit more solar and new batteries. All going well until by DNO refused to allow me to export any power from my battery to the grid, this seems counter intuitive to the aim of balancing the grid and put a spoke into my calculations. Do you know if there is an appeals process?
Thank you so much for considering me when joining up with Octopus Energy - that means a lot to me. And sorry to hear that your DNO is blocking you from exporting to the grid from your battery. In case I missed it, could you tell me about your situation again please? Did you already have panels and are now adding a battery?
At present I am on the Octopus Tesla tariff, but that is coming to an end late this year/early next.
With PV and a Powerwall 2 + an EV6 it will be challenging to find the best replacement !
I will be following your series on this with great interest !!
Cheers, Con - I'll see what I can do... :-)
We’re an octopus customer in rented social housing with solar panels, but no batteries
When we moved in the analog meter went backwards in bright sunshine
However changing to octopus required a smart meter
On bright days electricity is £0.00
It must have been so strange to see your analog meter going backwards! Great to hear you're not having to pay for electricity on those sunny days - every penny counts! :-)
I think the Flexible Octopus tariff is still the simplest as you can just leave your settings alone, i.e. have your battery storage between 12:30 to 7:30 when economy 7 charge is 17.73 per KWh then use your battery for your daily / evening time, if your battery is sufficient you can run on the stored economy 7 power all day, plus any solar can help top up the battery and what you don't use Octopus buy for 15p per KWh. On a Sunny day life is great and on a cloudy day you are still only paying 17.73p per KWh. We just try to leave our high usage days to sunny days when we have surplus solar if possible.
Hi Paul,
Provided your battery can cover all the day's electricity requirement, this is a very nice and simple strategy - sometimes the simplest ways are best! :-) I'm currently building a coded version of the utility presented in the video, and you've got me thinking... thank you!
Great worksheet Gary. I did notice an possible error in one of your formulas (in column M) which seems to miscalculate the discharge rate of the battery during the "FC" period. I believe if the battery is in this mode, then it will be forced into a charge rate so there should be no discharge possible, however your current formula seems to think there is a discharge value if the consumption is high over this period (as it is with me with my immersion heater and EVs charging at this time).
I've made a quick update to cell M4 (and copied down) to adjust for this: =IF($K4="FD",-MIN(MAX(MAX($C$7-$J4,0),0),N3*(1-$C$11),$C$13),IF($K4="FC",0,-MIN(MAX(H4-J4,0),N3*(1-$C$11),$C$13))).
May need some sense checking though.
Keep up the great work.
Hi Mat - thanks, and also thank you for taking the time to look into this bug! :-) What I'll do is update the spreadsheet and upload it as a new version that people can use!
Since publishing, I've been working (this week) on a coded web version - which has completely different logic, but I can compare the output of this new version against your suggested change as a sanity check!
Thanks again :-)
Actually, Mat - is it M4 or K4? Maybe the best way is if you could email me a copy of the spreadsheet with your change in it, if that's ok? Send to "me" then at symbol then my channel name (all one word) followed by dot com. Many thanks! :-)
I use agile with batt and solar atm which sometimes I get free charging and I know some people have been paid for using energy. Good work Gary
Thanks Keith - I plan to cover Agile in part two of this series - I really like the fact that Octopus is so forward thinking on tariffs Being paid for taking load off the grid sounds marvellous to me! :-)
Great video! Is there a way to automate all the charging and discharging? I have a 5kw array, with the Gen 2 Giv Energy Hybrid and 2x 5Kw batteries. The only downside I see for me is the Gen 2 Giv Energy charge rate is only 2.4Kw so I wouldn't be able to fill the batteries in 3 hours.
Hi Rohan, you're most welcome. Is this your inverter? www.givenergy.co.uk/pdfs/products/datasheets/giv-hy-3-6-gen-2.pdf In which case, the charge rate is 3.6kW, but maybe your batteries are limiting the rate?
I also have GivEnergy products: a Gen 2 GivEnergy Hybrid (5kW) and 2 x 9.5kWh batteries. I can only charge about half the batteries as well, but I'm ok with that because as we head Into sunnier days, the increased solar will quickly fill the remainder.
@@GaryDoesSolar Sorry, I was wrong, I have the Gen 1 inverter which is limited to 2.4kw charge and discharge. I think they announced the 3.6kw version a month after I took delivery of mine!
@@rohanchaffey3591 Ah ok - no worries - you can still half charge your batteries with off-peak (like me) then let the sun do the rest 🙂
Great Video Gary, loved the content and easy for homeowners to follow. Many thanks
That's very kind of you, Ecobubl - and just to let you know, the solar and battery installation you fitted for me week before last is performing amazingly :-)
I'll be making a video about it shortly...
wow what great info, I've ordered solar and will have a 10.5Kw battery plus I have a EV so this makes things really worth it I might think about getting a 3rd battery as well
Thank you for the feedback - very much appreciated! And great that you're starting your solar journey :-) Haha - yeah, big battery installations might become all the rage soon!
great vid - and thanks for the spreadsheet - who doesnt like a spreadsheet after all. Made the switch to Flux ealier today and its clearly aimed at the home owner micro generators- good for Octopus, and as you detailed each user shifting the curve slightly benefits everyone and Octopus. Ive set my inverter initially to export only for just one of the peak hours, time will tell if i can be bolder, but i seem to be runnig at twice your nighttime and nothing is running rate.
Thanks Charlie - I think my spreadsheet is starting to get out of hand though - lol. I'll likely code it up on a website instead...
I didn't understand the very last part of your comment - could you restate please?
Love your videos Gary, you are such as good teacher and explainer. I presume you teach others in your day job?
Hi Rob, thanks for the kind words. I do enjoy presenting, and this is a big part of my day job, which is in the mobile industry (I'm an eSIM expert).
Great work again Gary.
I am on Octopus Flux and trying to work out whether to use my battery to minimise import (and take export benefit as a second priority) or to maximise export and accept some import after the evening peak (as your utility does). I haven't yet convinced myself that the latter is worth the extra battery throughput and degradation for relatively modest extra import income. Looking forward to your utility.
My present strategy is a mix of the above. I avoid import before dawn by charging to at least 20% overnight (may not need to charge at all if evening consumption is low) and I avoid import after the evening peak by only force discharging to >45%. This works ok for my system with the present level of sunshine, but as I say above, I am not sure what the optimum strategy is.
Thanks for the kind words :-) Yeah, developing an optimum strategy is really hard - I guess the only real way is a bit of trial and error (and a lot of data analysis!). One feedback I had on the utility is that because of the "power factor" of certain appliances, 1kWh of charge into a battery might not provide 1kWh of useful power for appliances with a low power factor (anything with a motor it seems). I'll need to look into this...
@@GaryDoesSolar you don't need to worry about power factor.
Poor power factor (e.g. a motor with poor power factor compensation) means the load has to be provided with reactive power (kVAr) in addition to active power (kW). Reactive power only exists for AC systems so the "real" energy kWh is provided by the DC system (PV or battery) and the "imaginary" reactive "energy" kVArh is provided by the grid connection or produced out of thin air by the magic of your inverter (at the expense of slightly increased inverter losses)
Hi Gary, an update, on contacting the DNO (Northern Powergrid) myself they have agreed to let me export from my battery as well, seems that they have updated their policy so good news! - I had two solar installations and have added batteries and a new solar install with battery.
Wow - great news! And good to see DNOs taking a positive view around residential export. Sounds like you'll be in the money before long! :-)
Thank you for the video.
As we have a GivEnergy 8.2kwh battery and we are on Octopus Flux, I did a forced discharge test and took the readings from the smart meter the next day. The battery exported 6.9kwh from 100% charged all the way down to 0 (didn't stop at 4%). It used 9.8 kWh to fully charge back to 100%. The round trip efficiency of the battery is only 70% and I have now stopped discharging to the grid during peak hours as the gain is just 4.5p/ kWh and in my opinion doesn't worth it.
You're most welcome about the video. A 70% round-trip efficiency seems rather low - I'd be expecting around 90%. Maybe something to ask GivEnergy about... Shame also that the battery discharged to 0% - it should not have done that :-/
@@GaryDoesSolar
I’ve emailed GivEnergy and previously they responded within a a day or two, but this time it takes a bit longer. Will follow up soon
@@GaryDoesSolar
The GivEnergy app shows round trip efficiency about 92%, which is far away from the smart meter readings.
@@serraios1989 That really is strange. If I get the chance, I'll do a test with my setup...
@@GaryDoesSolar
If you do test your your battery, remember to record its temperature.
GivEnergy responded today and they are asking for it. Looks like I will do a repeat test soon
Unfortunatelly, I don't own a house and I don't think that I can buy one the next 5-10 years. So, no PVs or batteries for me. I don't charge my car so often (30Kwh every 2 weeks) and I have a big family (5 people) and everybody works on day-night shifts every week. We spend a lot of power in daytime and Octopus programs won't save me some money. Now I pay a flat rate of 27p/Kwh at British Gas. But I love your videos, you are doing the most simple and informative videos on that subject.
Thanks Chris - and one day I hope to get an EV myself. Worth keeping an eye on the various tariffs on offer (e.g. Octopus Agile) as they might just work in your situation (I'm thinking perhaps a battery only install to soak up cheap electricity periods - prices may need to drop a little first though...)
Hi Gary, Thanks for another in depth and thorough video. (Do I detect a fellow Engineer? 😀).
I have just had a 6.7 kWp array, GivEnergy 5kW inverter and 9.5kW battery installed.
My charge / discharge rate seems limited to 2.6kW so I can't fully charge / discharge in the 3 hour Flux / Peak windows.
You have a similar setup, but with two of these batteries.
(@7:11) Is your charge / discharge rate of 3.6 kW per battery, or in total, perhaps now limited by the inverter?
PS I've just spotted that my 5kW GivEnergy Inverter is the bottleneck limiting the charge / discharge to 2.5 kW. Am I missing a trick?
Hi Nick, thanks very much for the kind words - great to get this kind of feedback :-)
Now, yeah I have pretty much the same setup as you! My inverter and batteries are Generation 2, which means it can charge and discharge at 3.6kW. If I remember correctly, the previous generation had a charge/discharge limit of 2.6kW.
I've set things so that I'm charging all 3 hours of the Flux off-peak period, up to a maximum of 40%. This means I get sufficient cheap energy if the day is not so sunny, and I still have more that half the battery to charge via solar.
Maybe you could do something similar, perhaps?
@GaryDoesSolar Hi Gary, you're right, it looks like I have a gen 1 inverter, which is disappointing as it was only fitted last week.
@@nickbradley3966 Nick, did your contract specifically state “Gen 1”? If not, you could expect to have fitted the latest generation…?
Great video Gary. A very clear and concise explanation 👍
Thanks Dean - great to hear feedback like this, and thanks for watching my video :-)
A brilliant summary video Gary. Very much enjoyed it. Looking forward to working through your back-catalogue and future videos. Clear, factual and inspiring. I'm in the middle of moving to Flux and its exciting being part of the future. Unfortunately we only have a 3.1 kWp array and 3.5 kWh battery for now but planning to roughly double both once we get an electric car. We got a power diverter when we had the installation but as per your other video I'm now wondering whether it makes sense to run it now we are on Flux.
Hi Toby, thanks for taking the time to comment (and also for the great feedback!) Hope you enjoy my other videos!
I've been on Flux for a few days now and I can't believe that I'm being paid so much to export! I'm almost feeling guilty about it! Lol
I'm guessing your current array and battery is in line with your electricity usage, so I wouldn't worry too much. You'll still be exporting a lot as the days get sunnier.
And yeah, on the solar diverter - it's a real shame that with high export rates, it longer makes any financial sense at the moment, but who knows, if electricity prices start to come down (and consequently, export rates come down below 12p/kWh) then they could come back into fashion...
Great explanation of Octopus Flux and it's potential benefits. I've only recently installed solar / battery and I'm looking how to use it effectively. Are you planning to give an hints/tips on how to configure Inverters in order to be able to obtain the benefits you describe from Octopus Flux?
Thanks for the kind words, Stuart. Yeah, I'm keeping a wish list of future video ideas - and will add this to it :-)
thanks for your efforts in making the videos. I've used your octopus referral code as a thank you.
Hi Mark, you are most welcome! And thank you so much for using my referral code - thank really helps me out a lot! :-)
Main problem is during winter or poor solar production. 3 hour charging window at night limits on appliance usage. A 300L water tank will take more than 3 hours to fully heat up to 60c.
This tariff only works if you retain the battery charge for peak use and hope your solar can retain/ aid its charge. Cloud / weather and winter is its enemy
That's true, and it might not always be possible to do that. You might be interested to watch this video I made on solar diverters - might cause you to think about the benefits of using that (I used to be a fan of them, but now I'm not): ua-cam.com/video/6zc1g1bz0eA/v-deo.html
@@GaryDoesSolar Great video Gary. I've seen all of your contents thanks. Keep them rolling
Hi Gary. May I take some screenshots from your video on tariffs to use at a presentation I’m giving at my village hall. I would of course reference your channel. Rob
Yes, no problem, Rob. All the best with your presentation 👍🏻
I've always wanted a solar setup, I've been subscribed for some time now but only out of interest. I just bought a house which amazingly has 18 solar panels fitted on a south facing roof with 2 batteries. Bit of a dream come true, but I'm totally overwhelmed by the admin of it all.
We have a young family, so I don't have much spare time to be watching a hundred youtube videos on the subject and I have no idea how much energy we'll use in the new house. Looking at Octopus, I'm tempted to just go "fixed" for 12 months until I can get a handle of our usage and how I'm supposed to manage the batteries.
Hopefully I'm not doing a dumb 👀
Great to hear about your new house! Yeah, no harm at all, staying on a standard tariff for a year until you get time to look at everything. But if you have, or are thinking about about getting an EV, I would strongly recommend you switching to an EV-specific tariff (like Intelligent Octopus Flux, for example). Good luck with the solar installation.
If it's useful to you, you can book some of my time where, in say 30 minutes, we could quickly ascertain a good tariff for you and the family to be on: garydoessolar.com/chatwithgary/
Great video, thanks. I'm just having a play with the Flux Calculator. Cell B5 of the ORIG Sheet say Solar Mult and has a value of 9. What is that?
Hi Barry, thanks :-)
Now, did you mean cell B5? This is a blank cell. Let me know which cell and I'll check it out... By the way, there is a newer Web app version of the same which you might prefer: garydoessolar.com/utilities/dailymodellingutilitytest/
@@GaryDoesSolar Definitely cell B5. It says "Solar Mult" and seems to refer to cell C5 which has a value of 1.26.
@@GaryDoesSolar I just tried your Web version, and it's great! What azimouth and roof angle are the solar calculations based on? Any chance that can be editable for slightly more accurate predictions?
@@themorfill Are we talking about the same spreadsheet then? Here is the cell B5 I have in the original flux calculator spreadsheet: garydoessolar.com/files/cellb5.jpg
@@themorfill Hi Barry, great to hear! So the solar model assumes a south-facing array. That's not adjustable for the moment - but you can adjust the Maximum Array Output setting accordingly. For example, if you have a 4kWp array which faces SW, then out a value of say 3kW in.
This is a great video - thank you. I have a query re EV charging. Maybe someone can help. If I have a 6kwp array and lets say its getting 5kw in the middle of the day, but I have a 7kw EV charger, if I have a battery, theoretically I can get the extra 2kw from the battery giving 7kw charging - but can this be done through a 5kw inverter? Does the inverter need to support up to and above the EV draw?
Hi David, thanks for the kind words - much appreciated :-)
Here's my understanding of how it would all work. It depends whether the battery in question is AC or DC-coupled:
- A DC-coupled battery is behind the inverter so when it discharges, it is limited but the inverter's output (which in this case is already maxed out with solar). So, there will be an additional draw from the grid of 2kW to meet the needs of the EV charger.
- An AC-coupled battery's output is independent of the inverter's output, so the power adds up (5kW solar + 2kW battery) to meet the needs of the EV charger.
@@GaryDoesSolar That makes sense - thank you. I've had a really good play with your Excel sheet to model outcomes (1. 6kwp+Powerwall, 2. 6Kwp+9kwh other brand, 3. 6kwp, no battery and 4. No solar, no battery.). I think you're overestimating solar generation. Your peak rate is probably right (around 40kwh per day on a 6kwp system). For reasonable accuracy though this is should be annual/365 giving 18-25 kwh per day. This is really significant.
@@dinkdankdh Thanks for the feedback on the spreadsheet. I'm actually working on a web app version of the same, and in that I think I have a better solar model. If you'd like to try an early version and give feedback, I'd very much welcome that. Just drop me an email on "me" followed by an at symbol, then my channel name (all one word) and finally dot com 👍
This was very interesting . At long last we're getting a smart meter. After an 8 month wait.
My question is how easy is it to program the kit to follow your example of when to charge the battery, when to use the battery and when to feed the grid.
Presumably you need to buy kit that will do it.
I'm lucky we are starting from scratch. I'm in my late 70s so need a quickish payback.
Thanks generally for your videos. Very interesting and informative. With the smart meter on it's way I can start planning.
Hi Allan, great that you've finally got your smart meter sorted! Now, it depends on the kit you buy. For example, if you had a Tesla Powerwall, you can program it like this chap did in a video here: ua-cam.com/video/VrKSKPrdhak/v-deo.html
Good luck with whatever setup you put in place, and thanks for the kind words about my videos - I'll keep them coming! :-)
@@GaryDoesSolar thanks I'll look at the link
Hi Gary. I just want to draw your attention to a small think in your video "fingertip image" :) They are of high quality and stylish, but you may want to think about using the lower right corner of the image - or actually not using it. In particular, the text or a significant part of the image should not be in that position, where the UA-cam platform always places the black rectangle indicating the length of the video and now the white marking "14.20". It covers the end of the last word of the video's theme "riff?" Do you notice? It is therefore a thumbnail of approximately 300x170 pixels. So you might want to set yourself a "reserved area" in the thumbnail production medium, where at least the text shouldn't go.
Hiya - thank you for pointing this out - I checked it and you're right - it's obscuring (quite important!) text. I'll keep what you say in mind for future videos - every day I'm learning something new! :-) Thanks again
@@GaryDoesSolar You really deserve all the help you can get.
Btw: I haven't watched all your videos yet, but I'm interested to know if you've ever used the real background of your shooting environment without greenscreen stuff :)
@@MR-ub6sq Haha - that would mean I'd have to tidy my office, and that ain't happening anytime soon! 🤣
@@GaryDoesSolar Yeah :) Do you have expertise in AGM batteries? I have a tiny 240 Wp power plant and I bought a 260Ah 12V AGM battery for it. I asked the Finnish importer of this battery for all the documents, because this battery was the last one in the retail store in 10/2023 and it was a demonstration item that lacked all the documents. The importer sent me a document produced by the factory, which showed, for example, the cyclic nature of the battery if used each time:
- 100%...0% gives 300 cycles
- 100%...50% gives 600 cycles
- 100%...70% no less than 1500 cycles
So I understandably wanted to know what 70% is as a voltage value after two hours of rest. It was not mentioned in the brochure I received. I asked for such a table separately from the importer, who replied that I cannot get one because the RITAR factory has not agreed to supply one.
So I thought that maybe I need to follow a chart that I found on the internet with a google search. I concluded that by discharging the battery up to the maximum limit of 12.3 V, the battery would have a long life. After three months of use, I started to pay attention to the fact that the battery charge does not last long, and I even more wondered why the 25A 12V smart charger charges the battery from bulk phase to float phase in about an hour, when it used to take at least 5 hours.
Now I approached the importer again, and said that I really need that voltage table. Now they sent it to me and it showed right away that for this battery 70% charge shows 12.6V and 12.3V means 50% charge. What do you think about this? I got the impression that RITAR is a really high-quality manufacturer. Why on earth would they not provide their dealers with such essential information?
I think now I have paid for nothing because it seems to me that I have destroyed the battery in less than half a year. Am I mistaken? Thank you.
@@MR-ub6sq Although I’m not able to provide an answer to this, perhaps others reading this can…
Very informative. Thanks for the spreadsheet, and thanks to everyone who has helped you to develop it. I asume you will be tackling Octopus Agile soon too. Is there anything I need to know regarding choice of hybrid inverter to make best use of that tariff automatically. I understand that GivEnergy and Fox are compatible, but do they integrate equally with these smart tariffs?
Hi Jeremy, my pleasure - glad you're getting something out of my videos. Just to let you know, the spreadsheet has now be superseded by this web utility I made - far easier to use and more informative: garydoessolar.com/utilities/dailymodellingutility/
Regarding the batteries, I can only share my experiences with GivEnergy as this is the only battery solution I've worked with (my own solution). They have facilities that allow you to force charge and discharge at certain times of the day, so great for tariffs like Octopus Flux. They also have support for Octopus Agile, but I've never tried using that yet.
Great video, Gary. I have plenty of solar and a SolarEdge inverter + battery, but am stymied by two issues. Firstly, my utility provider won’t install a smart meter as the 4G signal is apparently inadequate. And secondly, SolarEdge don’t have workable time-of-use software yet.😢
Thanks Alan. Isn't it incredible that so many manufacturers are not anticipating how the market is changing...? I've only been looking at this market for the last 8 months, and even I can see that equipment needs to have tight integration into other equipment around them, energy tariffs, the weather forecast. That's one of the reasons I went with GivEnergy - they seem to get it.
Hopefully SolarEdge will wake up...
Excellent video! Which battery manufacturer/ system would you recommend to take advantage of these schemes most easily?
Thanks for the kind words - and my plan is to suggest some options in a future video (hopefully not too far away).... I have a GivEnergy inverter/battery myself and it seems to work well.
I moved to Flux yesterday. My setup is Sunsynk 3.6 inverter with 16Kwh battery. The 3 hours of off peak charging is not enough to top up the battery to 100%. Might have to invest in another inverter soon to double the charging capacity.
Hi Rizaul, yeah - that's a big battery compared to the inverter, but you know, over the next 6-7 months, you should get plenty sun to fill that battery anyway, yeah?
Thanks, a great explanation. I can’t have solar, drive an EV, currently on Octopus Go. I’ve enquired about battery installation but it seems Octopus doesn’t do them without solar. Any recommendations for a battery installation?
You're most welcome :-)
Now, you can add easily an AC-coupled battery to your house - you'll just need to get hold of an installer (doesn't have to be Octopus). Worth checking out various solar forums like facebook.com/groups/2197329430289466 to see if a battery without solar is worth it... Good luck!
Excellent video Gary! Very informative. Are you going to cover the Octupus Agile Tariff next? 😃🤞🏾
Thanks. Here is my video on Agile: ua-cam.com/video/MbUDGbnHHBE/v-deo.html ✅
Great video Gary ... and have been contemplating Flux since it came out recently. I don't have a need for EV charging ... and my solar setup sounds ideal for the tarriff.
I'm running a Sunsynk Hybrid inverter 5.5kw with 10.24kw battery storage ... DC coupled to 16 off 405watt solar panels on two arrays, SE and SW facing. 6480kwp
I 'll be testing you new calculator page just as soon as it's fully released. Looks a great tool in the decision making process.
Thanks Rog - yeah, would be interested to hear how you get on. Good luck with your analysis! :-)
Thank you ! Great video. We will install an 8kw Solar array + a Tesla power wall 2 and backup gateway next month, so this tariff looks very interesting. But my biggest concern is actually getting Octopus to convert us over to it successfully. This is because I have previous experience of them not reading my smart meter correctly. As a transferred customer from Avro, I was on a standard flat tariff, but had a dual register meter. Octopus only billed me for the day rate readings and ignored the night usage ! It took me 6 months to get them to apply the tariff correctly by reading both registers and charging the same rate for day and night usage. This required support from the ombudsman. At least I had the confidence that when sorted it would be easy to calculate the amount owed . With flux, it will be a lot more complex ! Is there any advice as to how to prepare for this with octopus to get over to it asap? It almost feels like they may need to install a new meter ? Thanks for listening 😊
Hi Richard, sorry that you've had a painful experience getting your billing sorted out. I could imagine there would always be problems with Octopus transferring over customers from a failed provider. Some of the pertinent data (like the fact that you were on a dual register tariff) might not have been transferred. And then, retrospectively trying to get that data back from the DCC might take time. Sounds like that's all sorted now though - shame you had to go through the Ombudsman, but that's why the role is there. Flux is actually a single register tariff, so I think you'll be fine. Worth emailing hello@octopus.energy just to let them know you've have problems in the past, and could they perform a few checks post-tariff change, just to make sure everything is working fine. Good luck and all the best!
@@GaryDoesSolar thanks for your reply ! I have already emailed them, so let’s see how it goes ! To make my dual register meter work with a single all day tariff they have set me up so that the same price per unit is charged day or night. So I guess they will need to apply the variable flux rates to both registers similarly. I hope their billing systems are up for it ! Thanks again.
@@richardtrundle2758 Ok, good luck with everything, and if you don't mind, please could you let me know how it goes 👍
Hi Gary, an update .. 19 panels and power wall installed Friday. Not used the grid since Saturday am ! .. I’ve applied for Flux tonight and been immediately placed on the import tariff. Export tariff will take up to 6 weeks ! My question now is , will they retrospectively credit for any export in the meantime ? I’m worried that if I now tell my powerwall I’m on flux, it will start to import between 2 and 5am, so that it can export as much as possible later in the day ? If I’m loosing the export credit for the next six weeks , I don’t want to buy , just to export ! Any experience of their way for dealing with anything I export in next six weeks please ?
@@richardtrundle2758 Great to hear, Richard! I doubt you'll get it backdated (I didn't) but it's always worth asking because you never know! 🙂
So, for the next 6 weeks, it's all about self-consumption, and you're going to find that REALLY hard, as each day brings the prospect of more and more sunshine! Argh!! Try to use as many heavy appliances as you can when the sun is out, and if you have an EV with an intelligent charger, it will pretty much soak up all your excess.
Excellent vlog in every way. I am currently researching to prepare for transition to electric. EV in van form too expensive at present, so concentrating on ground mounted solar and battery, portable or fixed (depending location restrictions). I live in a small old cottage so I am restricted somewhat.
Thanks - yeah, it can be a minefield trying to research solar - glad my videos are helping! Good luck with your solar plans - exciting!
Unfortunately it looks like Octopus still insist on MCS certificated installation which rules out people like myself who have self installed. This seems counterproductive to the goal of reducing fossil fuel usage at peak times so hopefully common sense may prevail in future. As long as an installation has DNO approval either G98 or G99 then I don't see any reason to not accept export. My DNO has granted me 4.4kW of export capacity on my self installed Victron/Pylontech setup, and although I can export the surplus energy, I won't get paid for it. So this just incentivises me to increase battery capacity rather than supplement the grid at peak times.
Interesting video Gary and very well produced as always. Thanks for sharing.
Hi @craigchamberlain, very interesting to hear that you self-installed. Do you have any more info anywhere about your experiences of how you went about doing this? Thanks
@@chaswinder Hi - I've commented on some YT videos and some forums but I've not published anything formal. I did give an overview on a forum but I'm not sure if I'm allowed to post links to other website here so I'll copy/paste the text below. Let me know if you have any questions.
I installed an "ESS" (Energy Storage System) a few months back with the intention of taking advantage of cheap overnight electricity to charge them up and then releasing that energy during the day when prices are high.
So, basically I have installed two 4.8kWh Pylontech US5000 batteries for a total of 9.6kWh. These are charged (and inverted) by a Victron Multiplus-II 48/5000/70-50 inverter-charger which can charge the batteries at a rate of 70A DC and can generate a continuous power output of 4.4kW and up to 9kW peak for 15 mins or so.
It can also provide battery backup for my house in the event of a grid outage. To enable this I split up the loads in my house onto two new 18th edition consumer units. The primary CU takes the main meter tails in through a surge protection device and then has RCBOs for the Cooker (40A), Shower (40A), Garage/EV (40A MCB) and the Inverter (50A MCB). The output from the Inverter then feeds the secondary CU and it has all other house RCBOs including 3 ring final circuits, 3 lighting circuits, smoke alarms and boiler. I also have a transfer switch to allow me to bypass the inverter for maintenance or if it failed. The inverter also has its own TT earth rod because the regs don't allow you to rely on the DNO earth in the event of grid failure.
I have an EV (2017 BMW i3) and have been on the Octopus Go Faster tariff for a few years. That allows us a 5 hour window (21:30hrs to 02:30hrs) each day when grid power is 8.25p/kWh (inc VAT) whereas it is just over 40p/kWh for the other 19 hours a day. So we charge up the EV and Pylontech batteries at the same time and then discharge the Pylontech batteries during the rest of the day so that we effectively pay 8.25p/kWh for all our electricity.
We've been running this for about 6 months so far and it's been great. We use something like 9600kWh per year, 2800 of which goes into the EV. We've reduced that a bit through generally economy savings but probably still use 5000kWh/year in the house alone. That's about 13-14kWh per day which obviously is more than the 9.6kWh of battery we have. However, we have also been running the dishwasher, washing machine and drier during the 21:30hrs+ window. Also, the battery only has to last 19 of 24 hours each day. My electricity bill for last month showed that 97% of our electricity was consumed at 8.25p/kWh and the other 3% was at 40.13p/kWh. The previous month was 95% so this wasn't a one-off.
Bottom line is that we are finding the 9.6kWh lasts all day most days and that's keeping 10% charge in reserve. It won't last all day if we are running all the appliances during the day and maybe baking stuff in the range oven etc. But that's unusual.
I did a lot of work on the spreadsheet before committing to buy the battery system and I worked it out as a 4-5 year payback period. That involves a number of assumptions, not least is what the price of electricity will be in the coming years, but I did the calculations very conservatively rather than as an exercise in justifying a new "toy" if you know what I mean.
The other thing is that Solar PV can be added to this system really easily by just connecting up strings of panels via MPPT charge controllers. MPPT stands for Maximum Power Point Tracking which basically means the voltage and current being output from the solar panels are kept within the most efficient window and can yield 99% efficiency since it's a DC to DC conversion rather than the usual DC-AC-DC conversion you get with a normal inverter.
My plan is to buy 16-20 400w+ panels, probably Trina brand and fit them in time for spring. That should allow me to charge my batteries entirely from solar depending on time of year and then just use Octopus Go to top them up as needed. The payback period with the solar doesn't actually change because the extra capital costs are offset by the lower running costs almost exactly. But it gives further insulation from energy costs in future and a degree of self sufficiency. I might also buy a third battery if I find that I run out of storage during the summer months because I can always dump some energy into the EV.
The Pylontech batteries have a 6000 cycle/ 15 year projected lifetime and I think they have something like a 7 year warranty which is extendable to 10 years or something. I forget the details.
I bought my kit from here ( essandsolarsolutions.co.uk/products/multiplus-ii-gx-48v-3-5kva-230v-ess-bundle.html ) and would highly recommend the company. It's a small business owned by a guy called Etienne and I've had nothing but great support from him all along. His mission is to supply the DIY market because he really dislikes the whole "MCS approved" racket that has also been commented on.
There is a great Victron community forum at community.victronenergy.com/ if you want to get a feel for things. The Multiplus-II is a solid piece of kit but it does make a bit of noise when running at full power so I'd advise choosing location carefully. The batteries don't work below 0C and prefer room temperature for efficiency so again choose location wisely. I can go into this more if interested.
Thanks for watching and also your comment, Craig. Yeah, I'm not sure why the MCS requirement exists for exporting on certain tariffs. I'll try to dig into this...
@@craigchamberlain Thanks so much for that extremely detailed reply Craig! For the inverter and mains aspects of the install, did you have to engage the services of an electrician to keep the DNO etc. happy, or did you manage to go entirely 'diy' ? It's this aspect of doing an install I'm particularly interested in (my own plans being to use cheap 2nd-hand solar panels with a proper type-approved grid tie inverter, which I'd want to do diy as much as possible). Many thanks
You have a very similar setup to us, 5kVA MPII and 12kWh Pylon batteries. So frustrating they dont accept it on SEG when self installed with no MCS even though the DNO are more than happy for you to sync with the network! I can appreciate the MCS need when we had FIT and no smart meters as generation was a guess and you wanted to know what was said to be installed was actually installed. Now they could easily stipulate that you need a smart meter to get SEG without MCS and that would cover them as it would only ever record actual export and can't be fiddled. That with the DNO approval would mean things are as safe and secure as with MCS but also helping the grid. I've tried to Tweet Greg Jackson on this several times but never had a response. Unfortunately it would take someone with enough visibility/followers to self install to get them to take notice.
I'm on the Octopus Tracker tariff which is regularly giving me rates of around 21-24p. With the Outgoing fixed at 15p it doesn't seem worth risking the higher day rates of Flux. If the tracker rates go up it might be worth switching though.
Thanks for this info, Mark. I'll take a look at the Tracker tariff. Great to see Octopus offering so many different kinds of tariffs...
@@GaryDoesSolar they've actually just limited signups to 50 a day now because it was so popular and there's apparently a 6 month waiting list unfortunately. Biggest saving over the winter has been gas though which has averaged about 6p / kWh. Today's rate is only 4.97p - less than half the EPG rate.
@@markianross Wow - that really does sound popular! Ok, I'll make sure to add that into any video I make on it - thanks for the info!
Gary, have looked into V2H, V2G, V2L and V2X? I'm wondering if that would be a viable solution for a home battery instead of the ones you've shown in your videos.
Hi Paul, it's on my list - and I'd be focusing on V2G with a little but of V2H... Just waiting for support for those technologies to get a little more traction first...
I am with Octopus Energy 🐙 and have just installed Solar and a battery.
Which Octopus 🐙 Energy Tarif do you recommend? FLUX OR INTELLIGENT
I can't provide you with advice (given liability considerations) but I can say what I might do. And in fact, I'm on Flux at the moment and have been so since March - it has been great and I've made money almost every month. As winter approaches though, with less solar generation and consequently, less solar excess to export, Flux becomes less beneficial. I don't have an EV otherwise I'd be straight onto Intelligent Octopus Go (and if my situation didn't qualify, then the basic Octopus Go tariff). So, I'm actually eyeing up Octopus Agile... Hope this helps, James.
@GaryDoesSolar Thanks Gary. I am going Intelligent
Hello Gary I am enjoying your videos, I live in Ireland, unfortunately we do not have octopus, but we do have some cheap rates. Can you charge two batterys at the same time.Thank you Tom.
Hi Tom, great to hear that you're enjoying my videos - I'll keep them coming. Octopus is expanding all the time and I'm sure it won't be long before they're present where you live. In the meantime though, keep an eye out on all the providers you do have there - they're starting to wake up to the needs of solar, battery and EV owners and are building tariffs to suit...
Yes, you should be able to charge two batteries at the same time, provided they are controlled by the same string inverter. The inverter will ensure the batteries remain at roughly the same level of charge each.
Hi Gary, What have you heard about Octopus bringing out a new "Intelligent Octopus Flux" tariff?
It seems to be restricted to owners of GivEnergy batteries, has the same import and export rates, no cheap flex rate and I think that Octopus would control the importing and exporting of one's battery.
Hi Nick, so, it's still all quite new, and details are sparse. It's only open to GivEnergy battery owners initially, but that is expected to expand to other brands over time. The new tariff is currently being trialled with a subset of customers, to iron out any problems etc. I'll be making a video on the tariff shortly...
@@GaryDoesSolar Hi Gary, I look forward to that.
The tariff sounds great, I've signed up to their waiting list.
Interesting video, but more info on export tariffs would have been helpful.
The technology is very capable of duty-cycling its energy collection/storage and dissipation elements but economic return on capital employed is ultimately determined by the values of feed-in and feed-out tariffs.
In the absence of long term government regulation the wild west UK energy markets will continue along its chaotic path.
Thanks for commenting - yeah, like you, I believe export tariffs are a key catalyst for driving the home solar market. I do plan on covering more on these in future videos.
Hi Gary I just had a look at your spreadsheet- very neat - I note that if I remove the FD switch to indicate that battery not dumping then the battery remains fully charged through the day from solar, whereas it would show greater savings if the battery was discharging through the day and more solar was going to the grid as the price gain for solar export is greater than the cost of charging?
Hi Geoff, that sounds good - let me try that out here. Thanks for highlighting :-)
I just moved to octopus today , will add your referral link/ code
Thank you
That's so very kind of you - thanks! I really appreciate you doing this for me :-)
Hi Gary, great content and really helpful spreadsheet. I have spotted an error, Once the battery is fully charged in the Off-Peak period, the spreadsheet still shows grid import for the full charging rate even though it wouldn't be charging once full. Set Battery size to 5kWh to see what I mean.
Hi Mark, thanks very much for spotting this! That's a pretty bad one too! I'll take a look this afternoon... Cheers
Thanks for the brilliant explanation of flux. We are thinking of changing from economy 7 to flux. Do you have a table to work out how long it will take to pay them off? And which tariff is best for me. Thanks
You're very welcome, Dawn :-) So, I am working on a utility at the moment that can give you a view of how well your setup will perform with Flux (or other tariffs). I'll post this link after this comment, but in case UA-cam automatically deletes links, just look in the video description for it. You could also take a look at another video I did a while back on calculating your payback period. Again, I'll try to post the link below.
Utility: garydoessolar.com/utilities/dailymodellingutility/
Payback video: ua-cam.com/video/FvjuJQZRrvA/v-deo.html
Really enjoying the videos. My install was commissioned in June after a 1 year wait. 4.4KW (12 x 370w) panels, .6 KW Giv Hybrid Inv (gen1), and Giv 9.5KW battery. The Inv limits the battery charge rate and the supply to the house to 2.6KW/h, which is quite limiting. You are higher at 3.6KW/h, but I think 2.6 is too limiting for adding another battery to my system. I think however adding a GivEnergy all in one would work for me, as it connects directly to consumer unit, can be charged from grid or solar, and gives 6KW/h charge/discharge and think this would be on top of my 2.6 from the inverter. However, I think it may need a G99 application, and pricing may be high just now as only released - would be interested in your thoughts on GivAllInOne.
Also already on Flux, but thinking Agile might be better for me in winter - when not likely to export, and maybe take advantage of plunge pricing to charge battery, and charge cheaply through night. 3 hrs on flux with 2.6 charge rate I cannot fully charge battery.
Hi George, thanks for your kind words on the videos :-)
And yes, you're right, the charge/discharging rates on GE products are not great. But adding a new battery/inverter as AC-coupled will increase that. I'll be covering this and other things in a follow-up video I'm making on batteries...
Hi Gary, loving your videos, thank you!
Your calculator spreadsheet seems potentially useful but as you acknowledge in your video, it doesn't yet work for Octopus Flux as it only accepts 2 of the 6 figures from an Octopus Flux quote.
Personally I'm initially looking at a storage only installation (13kW battery + 3.68kW hybrid inverter) to take advantage of the difference between the Flux import and Peak export rates (with the hybrid inverter to support potential future investment in solar) so I'm looking to model that configuration to see how it plays out over time and whether it makes financial sense.
So here's hoping that you will be updating your spreadsheet so that it has inputs for all 6 of the rates found in an Octopus Flux quote so that the spreadsheet fully takes them all into account.
It's also missing DoD (usually 90%, but does vary) and for future proofing should also allow specifying the number of Flux and Peak hours.
It might be better to allow the user to specify the import & export rates for each hour of the day, allowing usage not only for Octopus Flux but also any other tariff where the rates vary by hour, which would work for future tariffs which could potentially have more than 3 different sets of rates.
Hi Marcus, thanks for the great feedback! :-)
Now, the spreadsheet is already populated with the pricing for all six tariff periods for Octopus Flux (normal, off-peak, peak) in fact. Check the values in columns N and R - you should see the different prices depending on the time. Each hour can have its own price (for both import and export).
Is that what you were referring to, or do I need to add something else to the spreadsheet?
In any case, I'm working on a web app version, which is much easier to use, and if you'd like to try it out before I release, please email me on "me" followed by an at symbol, then my channel name (all one word) and finally dot com and I'll reply with a link.
Very well explained. Looking forward to the new app. 👍
Hi Trevor, thanks :-) And you can try out an early version of the web app here: garydoessolar.com/utilities/dailymodellingutility/
Really good video. For me this model works well Spring, Summer, Autumn but the Winter would cost a fortune with not much solar and only night charge time of 3 hours, this is very restrictive for an electric only house. Fair play to Octopus for trying out different tariff models. Why aren't the other electricity providers trialing these tariffs? Also need the UK electricity tariffs to be much more stable in order to get consumers to invest. I'm on Octopus Go Faster with 11KWh of batteries, works brilliantly.
Thanks Phil - yeah, the other providers seem to be asleep at the wheel on tariffs (meaning, their billing infrastructure isn't set up for this, and it's too complex/expensive to upgrade, maybe). I don't think you sign up to Go Faster any more, so hopefully, you've a while to run with it yet... :-)
@@GaryDoesSolar yeh I’ve got until August on GO Faster. We are lucky to own a Tesla so I think I can move on to Intelligent tariff. Your video was really interesting, just looking at the rates on the Flux tariff I assumed it would be no good for me. However it would be really good except for Winter. Hopefully all tariffs will come down before the next Winter!
@@GaryDoesSolar The other suppliers could buy/rent a copy of Octopus's Kraken, as sold in other countries.
This looks good. So basically you are saying that this combination of solar, battery and energy tariff is making money for you. Could this be an option for everyone? Also outside of Oxford, the UK? How is the situation in Ireland, Holland, Germany, Poland, Finland and Greece? Gibraltar, Malta, the Falklands???
Thanks for taking the time to watch, Freek. So, in the UK, I would say there is the opportunity to make money using the Flux tariff. In other countries, it depends on whether the energy providers in those countries off similar tariffs. If they do, then the same opportunity applies.
That was a nice, clear presentation. When I discuss solar and battery installations with friends and family, instead of 'pay back time' I try to emphasize that they should think of it as a dividend on a capital investment - and how much better and more reliable a return they get compared with stock and shares or, worse, money sitting in the bank. Nowadays, £4k will get you a solar PV system which will generate (at today's high rates) about $500 per year in savings - that's a 12.5% return on capital.
On batteries, the equation is not quite so good. I point out that there is a capital cost to charging batteries - they wear out. A typical battery can be charged 4500 times - still 12.3 years at one charge/discharge a day - but if you spend £5000 on batteries you're likely to get about 12kWhr of storage. After you've done the sums, this means that every time you charge the batteries, your capital cost is about 10p per kWhr. So if you are using that battery energy to offset paying 34p per kWhr then your net saving is 24p per kWhr over the long term. If you are using the grid to charge the batteries (rather than solar) then you have to add that cost on to the 10p capital cost. So 20.24p + 10p is your actual cost per kWh and then you're offsetting this against 33.73p regular rate - so that's only 3.49p per kWh saving (net long term). What we need are cheaper batteries(!) - cheaper per kWh charge/discharge cycle - it doesn't actually matter how long they last: a battery that only charges 450 times but costs £500 for 12kWhr is exactly the same as the expensive, long life battery.
Thanks for the great feedback. And thanks also for sharing this insight, which I think will help others a lot!
Hi Gary , I have been with Octopus for sometime now, i have a 4 kw solar panel system and 7.8 kw of battery storage , currrently on Octopus outgoing using Econ.7. I have expressed interest with Octopus Fliux but as yet undecided. The seg rates look attractive however the import rates at peak times are quite high and thats a bit of an issue however during the summer months could be well wortth it and maybe switch back arouind October time. Seems like no brainer but is there a catch. By the way your videos are great .
Thanks for the kind words. I’m thinking that because you’ve got a good ratio of your battery vs array size, that you should be able to charge enough to get you over the peak period, more than half of the time? And any costs you do incur over the peak period will be offset by some of your export revenue? And depending on your battery, you might be able to get it to hold charge until the peak period?