I'm convinced that battery is worth it. It gives you flexability: who knows what tarriffs will do in the future as more renewables come on stream. If you can store energy and charge a battery fast you will always be able to access the cheapest rate for all your power. Currently a big enough battery enables you to make money even on days with no solar by buying cheap and selling high. The absolute cheapest way to add a battery will be to buy raw cells and a case from direct from china. You can take some of the uncertainty out of it by purchasing from fogstar in the UK 15.12kWh for £1560 currently. You'll have to assemble it but it's not that hard and there is plently of help online. Down side is no extended warrenty but set against that, you built it so if it has an issue, you can fix it.
When I purchased my system I ran the numbers and buying cheap then selling high makes quite a big difference over a year. In my case it made the difference from not being worth doing to being just about worth it.
Seplos is an option if you want to build DIY yourself. Although personally I prefer £2K (Black Friday sale) for the Fogstar 15.5. UK warranty (8 year) and Support. Better BMS and Heater included. All this benefit for £440 each, and you don’t have to build them👍.
@@Burtis89The Fogstar 15.5 was £2k on the Black Friday sale. I’m sure they will be discounted again at some point. An installer could go the Fogstar wholesale route and then you will get the VAT off as well👍
You cheeky little tease. Your two questions at the start are exactly the two questions I've been waiting for you to answer definitively! 😂 Thank god you've been publishing some banging videos in the meantime whilst I wait on the answer! 🎉 Loving the content as always. When you do answer I'd like to see the option of battery with NO solar explored too. Is that the better option financially? I suspect that with the way energy markets are the best hedge it's both battery and solar. Sometimes it's best to use what you generate, sometimes export rates are high, sometimes low. Sometimes you'll get a cheap overnight tariff, sometimes the gap between peak and off peak tariff will fall. Market forces. Need to be able to manage in all those circumstances but it's costly and the payoff may be too long..... Cheers again from the great vids
Thanks for producing the video , solar edging towards the naughty list , looks like batteries are on the cards , you being you a deep dive into the reality of each battery make and not listening to the BS or R/S being the seasonal equivalent.
If you can add enough battery capacity to survive on mostly off peak energy, I would guess you'd be able to get your average price per kWh below 10p. Octopus Intelligent being the obvious tariff. I'm enjoying my recent switch to Tomato Energy, but we'll see how long it lasts!
@@crm114. Yeah 25 here and we're about the same. Although our general house load is too high and slowly eats away at it. The move to Tomato Energy has helped as it's 5p overnight and then I charge back to 100% for 2 hours in the morning at 14p
interesting stats and numbers. as others have said, especially when using a heat pump in the winter, a battery system will sort itself out in a few years, likely within warranty. an observation i have is that a battery is almost the inverse of the agile mentality y. with agile, youre gaming the system and timings where you can (and some batery inverters coupled with HA can do this too) but generally with batteries youre on ToU tarriffs, and using overnight rates. for me the penny dropped whn i had an export rate: once youre exporting, batteries and solar are decoupled and its less about using what you generate, nd more about maximising the I/O equations. For minimising the bill, Solar gains are made from exporting at 15p as much as you can, and not importing when its 20+p, and likewise the battery gains are made through covering daily use with overnight power pricing. My rule of thumb is, if you can cover 100% of your daily usage (for 90+% of days) in the winter (HP usage is going to massively challenge that!) thats the rigut amount of batery. rest of the year you can safely export that battery at a time that suits you for £££.
We're on Intelligent Octopus Go and the battery always beat out the solar as a result, as it lets us consume electricity at around 8.1p per kWh, according to home assistant our cost per kWh imported (when taking solar exports into account) has been 3.1p so far this year, which is pretty fantastic and is almost entirely down to the battery system and consuming almost no peak power at all. I do find your NW roof experiment really useful, we have a small south facing roof, which has 5.8kwp of panels, but our north roof is 3x the size, part of me wonders if it's worth sticking a load of panels on there and accepting that they'll only run at 50% on average, which would be pretty good as we could effectively over double our array production
If you go for battery there is something to be aware of - most hybrid inverters pull around 100W to 150W pretty much all the time. That means you could be losing up to 3.6kWh per day simply to run the inverter. The only hybrid inverters I know of that don't are Victron at around 30W - 50W for most of their units. As they are designed mainly for off grid use, they are highly optimised for efficiency. The down side is cost. Victron are more expensive so you need to run the numbers to see if that efficiency gain is worth the extra cost.
Yes! My off grid cabin 3K Victron Multiplus draws 10W at idle. You may have trouble finding people to install a Victron system. Here in Canada a friend met with the excuse that Victron wasn’t CSA approved.
From my experience this year with GivEnergy 9.5kWh battery and hybrid inverter, I can tell you that the inverter draws about 36W and the battery about the same again.
Looking on Power Forum the Sunsync has a Grid Trickle Feed setting somewhere, which in their area defaults at 50w but advice is to drop it to 20w and check that Electic Meter is still happy as it can trip it if too low. I'd be interested in the outcome as planning a setup similar to @UpsideDownFork 😊
So far this year we have imported 9000 kWh, 99% of it at 7p overnight and exported 6000 kWh at 15p so well happy with that, two EVs and a heat pump to power with two powerwalls providing power all day long, avoiding the horrific agile prices seen this week, but hey ho they will be back to normal for you next week!
@@UpsideDownFork For just short of 3 years I have had a very similar solar set up to you a split of 6.5kw, just over 2 parts NW to 1 SE, 13 on the back and 6 on the front of the house, I also have a Tesla Powerwall 2. I will be honest if I had my choice again I would have had 2 Powerwalls fitted and left the solar panels in the shop. We are on the Octopus intelligent Go tarriff, were we charge the battery, have a Cupra hybrid, use the washer, the dryer and a couple of ceramic electric radiators during the 6 hour 7p cheap rate. The October to March period the panels are as much use as a chocolate fire guard, even March to October has been a big disapointment this year as it just seemed to rain every day this year. As an example 25th of October to 25th November we exported £5.16 an average of less than 1kw a day produced. I am thinking of going in a different direction to you regarding heating and hot water as we still have a large floor standing combi boiler I would like to get rid of and I have read so many conflicting reports regarding heat pumps. I am looking at a Klover 120 pellet stove in the kitchen coupled to a unvented cylinder in the garage, I will heat the hot water in the cyinder during the cheap rate when we aren't using the stove in the warmer months. If you can afford it get a Tesla Powerwall 3 fitted, supposed to be even better than the 2 and the 2 has been brilliant so far for us. All the best which ever you choose.
I have a 9.5kwh battery and even in November and December I manage to export from the battery at 15p most days and recharge at 7p, so with a Powerwall you should be able to do that I would think ?
I have a 48v pack from a forklift. It gives me 70kwh of storage. Yes it’s slightly bulky, but it’s not sitting in my living room at the end of the day. Connected to a Sunsynk 5.5kw, keeps me off grid for 8 months of the year, and off peak for the remaining. Minimal maintenance, and no worries about cold weather like the lithium. At £28per kWh of capacity you will not find better 👌🏻
@ Big old, tried, true and tested IFLA 😉 Takes up the footprint of a standard pallet. No gimmicks, just straight forward energy storage that does exactly what it says on the tin 👌🏻
Thanks for putting this out, glad to see a fellow energy geek. Adding in a battery would give you a buffer for that agile pricing. The real cost is to the family as you will have another set of factors to manage day to day😂
It was inevitable you’d eventually end up with a battery system particularly with the heat drawing so much energy in winter, but credit to you for seeing out the experiment. There seems to be so much more choice with home batteries now you will no doubt have fun choosing between them. My Giv Energy hybrid system has been faultless and has served me well, so I have nothing but praise for them. Good luck with your choice.
Thank you! I'm fortunate to have a complete year of heat pump and solar data. From that I now know that 17.5kWh is my ideal battery size. Any more than this I'll encounter diminishing returns quite dramatically, but 15-20kWh seems the sweet spot for my home and heat pump load.
From experience, Givenergy is nice with the API and octopus integration and excellent customer service. The all in one is great, the true size is within your range. There are cheaper options. A simple hybrid inverter might be the best bet
@@UpsideDownFork Remember, you don't need to factor battery size for the duration of the cheap slots, if you are using the ASHP and charging battery/car during a presumed 6 or 7 hrs of cheap slots, the battery only needs to be big enough to cover the remaining 17-18 hrs.
I've moved from agile to octopus cosy now the fixed cheap rate is great and running the heating/water in these hours I've found it to be very good value
My single pylontech battery with a minuscule usable storage of 3.4kWh has saved me more money over the year than the amount I made from exporting excess energy from my 7 solar panels. I am on octopus agile, and my strategy has been to fill up the battery overnight as long as the rate was less than the fixed export rate of 15p/kWh. That way I have started exporting quicker if it was sunny, or not used grid energy on those dark nasty days with no generation. I’m going to double up with a second pylontech next year as in the winter the light is gone by 3pm and the battery is empty by about 8pm most nights. This month even with those mad days of 99.9p/kWh during the peak periods on agile my average rate per kWh is under 14p and according to Octoprice I have saved over £40 for my import over what I would have paid on the standard variable.
I would be looking at the max kWh daily usage and trying to get close to that with battery storage so you can charge up on cheap, green electrons and discharge when it’s expensive and dirty. If this seems like too much, make sure the batteries can force-discharge onto the grid because then you can discharge just before off peak starts and make more money exporting than you paid for the power in the first place. You’re then helping to balance the grid and making a tidy profit to boot!
My max kWh consumption in one day this year is 82kWh but 40ish of that was car charging and approx 10-15 was further load shifting on the cheap rate. 30kWh would be great but anything over 15 will not see great returns as the first 15 will. Diminishing returns are definitely a big factor when choosing the optimal battery size.
Really look forward to your video,s but would ask if you could not race your mouse over screen so fast as I end up like a cat trying to keep an eye on its prey! I found your video on the Vaillant controller excellent and it’s given me more confidence in its use. Keep up the excellent Vidoe’s.
Great video. I held off on solar until I felt happy with battery tech. A year later and I pulled the trigger getting my installation in early September. I went with Sigenergy hybrid inverter and batteries. Let me know if you want to discuss my experience so far.
Early sig adopter here too..m great piece of tech. Currently riding agile in A.I mode. Totally hands free. Really impressed with how it's handled this awful weather
I saw 100p kWh 12-12‐2024 6pm on Octopus Agile! That's 6.6x what they pay for export at 15p. Having a cooked dinner will become the status symbol of wealth!
The savings from the use of the battery during the last year was less than £250. We are on intelligent go, 2 ev’s, gas boiler(stays till it expires), 7.5kw pv. At current energy prices the battery will never pay for itself
That’s interesting but not surprising, I do see some people gaming the system a bit charging overnight and exporting the charge back to the grid but to me at least that doesn’t really seem to be a good idea, goes against the point of having battery’s to me at least.
Thanks for sharing this experiment and I understand why you jumped ship a month early. Seriously though, December is looking even worse than November for Agile rates with a couple of miserable, windless days already. Let's hope for some more named storms when the electricity price drops to zero (or better)! We have Pylontech batteries which are modular and easy to expand in 2.4kWh increments to get the size you want. Maybe you can save money by getting a smaller battery than you think you need and adding to it later, if necessary? They're also compatible with a wide range of inverters. With any battery system, you'll lose about 10% in conversion losses so factor this in. However it makes gaming the system with Octopus Agile so much easier and more effective. Looking forward to seeing how you get on next year.
1% eh, well great video, so you admit you lost the battery battle… I thought you may! I have been riding the export £ buffer out same as you, November finally killed it… Data shows this year (so far) I am up to 18MWh usage with 32% from the grid, Now I still have a DFS credit with Octopus of over 110k points which I could cash in… but DFS rates suck in comparison this time round in 2024, so not something to rely on in the future! I have never used peak rate energy, not once in the last 12 months and am rinsing that octopus cheap rate every night… I fully expect to be able to ride this out till the sun returns. Other than charging cars and batteries I do exactly zero load shifting to anything else in the home. Time is money also and no one seems to factor the cost of messing about with devices each month. Look forward to seeing your next challenge!
I have a similar panel array but with 25kw of batteries, and also on agile. My heart goes out to you last week being crippled when rates hit 99p last week, also stayed high for many hrs, with no batteries. they are easy to DIY install and you can escape VAT as well. I use 5 X4.8kw pylontechs and we can buy them for £930 each right now. Can get even cheaper with fox,
We've bought 2 x 15kw seplos DIY batteries for the same inverter as you, being installed tomorrow. First time solar, and I decided the main function of the battery has to be saving money, hence the DIY battery packs. Hopefully this is a productive journey!
I have 8kW Solar and a Givenergy All In One. Works well and full automatic switch over for powercuts as well as 6kW feed. I would have bought 2 at install but they did not have it working then (very slow to get it available) though it now is. However, filling the battery & EV overnight on the 7p rate (IOG) and then exporting all solar excess at 15p I very seldom run out of battery. Though I do not have a heat pump yet until Gas boiler dies. Only very few days where I need the 23p rate at all and that is often for a kWh at 10pm until the cheap rate kicks in again at 11:30pm. Hence glad I did not get the 2nd battery. Also agree with another post watch out for conversion losses - I think mine is well over 15% in & out.
Love all the data. On the EV charts, would be interesting to also include the miles with the kwh so viewers can transpose to their use for an approximation. Maybe in future? I understand its all circumstantial, many variables given different location, house, house usage/EV driving style or type of drive/ house/hp usage, kit itself, etc, though it all provides a sort of approximation. Especially by the time you see similar charts from a few different people. Cheers
ev drivers in summer ought to do nightshifts, allowing any solar excess during the day to be car stored or just keep on ignoring the fact of Carbon Shifting, and feel OK until vehicle disposal. great vid
It's just a given that we need back up power, that can be solar, mains,battery, whatever but redundancy is just an obvious requirement. panels are pretty much there to do both jobs if used with batteries and go together like bread and butter
Another potential gain when installing an oversized battery system on agile tariff is the option to offload all your spare capacity to the grid at peak evening rates knowing you can then help the grid out again later by putting in a very large charge if the power rates drop to low single figs or even negative. This way your spare power can provide additional income on top of any solar exported, to some multiple ratios of power exported verses imported. With more turbines being commissioned daily (new uk wind generation record on 18th Dec), and with twice the amount planned low rates every time the wind blows will become more regular. Export power rates to households are being given at best break even rates. Always DIY install batteries..so easy to do.
Fogstar have some decent DIY kits available (based on Seplos BMSes). The first generation Seplos Mason (horizontal batteries) are not so convenient because of their very specific electrical connectors.
I have Tesla power wall and on octopus intelligent. I put second powerwall in to cope with heat pump and this keeps my average tariff about 8 p . Interested to see which tariff you go for . Thanks for content 🎉
If you can generate excess from your solar, getting a battery will help store some of the excess to use instead of using from the grid and offset. That way peak power can compensate from battery instead of peak grid rates
Total Imported 1253.80kwh for £96.02 Exported 138.52 for £20.78 Heatpump was 272kwh cost £19.04 Cars took 653.5kwh cost £45.75 Ripple saving £19.23 (5.2kw solar south facing - 2x Powerwall 2’s and a Dakin 4kw Heatpump).
Do you use a generic forecast for your system, that is the same for every year, or is it generated for and specific for each year? Where do you get your forecast from?
I had my Agile bill in today: average import rate was 9.30p/kWh; roughly 400 kWh consumed. My setup: -8.5 kW southern facing array, with shading from trees to the east -SolarEdge Optimisers -1x Powerwall 2 battery -No Heat Pump (gas boiler) -No EV -Electric cooker -Two electric heaters (used only when Agile rate is lower than gas unit price) -Immersion and Eddi to supplement gas hot water Solar production for November was down 10% from last November, which was better than expected from what was a miserable month, but a late burst of sun brought some respectability. This is the first month since March where my exports haven’t covered both my import and standing charge - Flux from late February to early October; Agile and fixed export since then. But export still covered about half the cost of import and standing charge so not too much of my summer credit was needed to cover the shortfall. My exports are helped a lot by the Powerwall discharging stored energy ahead of lower Agile import rates, when the Powerwall then recharges, allowing me to pocket the difference between the 15p export and whatever rate Agile is charging that evening/morning to recover the exported energy.
@@UpsideDownFork Thanks; the battery has been such a key part of this for us, it'll be fascinating to see how your experience contrasts with your current data.
I would think pylontech would be top of the tree for battery? You can rack mount them and easily add more. They also seem very well priced at 1.3 k for 5 kWh. Thanks for the vids, been watching all year!
Sigen battery system is excellent but you have your inverter already and I haven’t checked on their compatibility with others. But as a whole house modular back up system it is impressive . After only a few days in the current gloom I concluded battery storage would win over solar with the caveat that you obviously need solar in the event of a grid disaster .
@@pmb9172 thanks. I'm calculating my system to cater for the best whole year, rather than a few days or seasons. That Sigenergy stuff looks fantastic 👍
Thanks for the update. I have seen which tariff you are on already, but interested to see which battery you go for. Will it be a smaller battery to get past agile peak, or a larger one to last all day on an EV tariff?
Great to have all that data. I have a Growatt Inverter, which I think has a port for a modem but not sure. Does anyone know if I can just plug that in? Also, our Smartmeter had stopped transmitting since January. British Gas say they are on it, but it takes ages. Also means that I can't use any of these smart tariffs.
A few observations / comparisons. You may not have been using the car more, it may just be the cars efficiency dropping as it got much colder. There will definitely be at least an element of that. Also lots of short trips are less energy efficient than fewer longer trips and thats more likely this time of year. I have 20 panels all s facing but 8 in shade part the day so almost the exact opposite set up to you in terms of panels and direction In November i exported 198k for a grand total of £30. (also on Octopus FE) Actual solar production was 271k. Essentially the first 3k a day of my solar ends up going into the battery there seems to be no way of stopping that. If i could be bothered i could force export that every day after the suns gone down but its too much hassle and it would probably only save maybe £50/year (because although id be exporting at 15p id be importing at 26p for that hour My whole house (gas/electric) for Nov was £119 plus another £24 for the car (344kWh@0.7p). Actual bill for the month after export was £118.
I'd agree with your comments on the EV being less efficient. I have an MG5, and the efficiency drops about 40% when using heater, wipers, lights in cold weather. The drop off is pretty stark below 6-8 degrees. I use a mechanical dehumidifier to reduce the need for demisting. The MG5 is the "dampest" vehicle I've ever owned.
@@UpsideDownFork the face-lift uses a heat pump, so less of an issue. I believe the short range uses a different battery chemistry, which copes better at lower temperatures.
What % rate do you use for payback period calculations. Loss of intrerest on money you have (3.5%) or mortgage rate? I dont know if you have heat recovery systems but I consider they work particularly well in an electrically heated house.
ROI calculations coming soon in a dedicated video! I've briefly looked at MVHR. I've been told that our house is too leaky to be suitable but haven't dug any deeper.
I don't have any solar, batteries or heat pump, but if I did go electric, I'd just buy a battery. Tomato Energy is only 4.,7p from 00:00 to 06:00, 12p from 9:30 to 11:30 and 22:00 to 24:00. Otherwise 22p. Easier installation and quicker payback time.
About the NW roof, I'm very interested as it's our best bit of roof. In midwinter the sun gets up less than a third of midsummer (still only 60°!), the day is of course shorter (less than 8 hours) and the sun sets much further south. All of which means bugger all light. Add the overcast December and I think it will be very poor, however you have shown it does generate a good whack year round.
Yes, as said, a shallow pitch is best for a north facing roof. Ours produces amazing figures in the summer months, frankly unbelievable the amount of generation we got from them in May, June & July.
I think you should stick with Agile (use the grid as a giant seasonal battery) and get a battery that is just big enough to cover your needs during the 4-7pm peak.
That's been my working assumption for many months. Basic calculations show that this is clearly the best financial strategy. The challenge with that is that my hybrid inverter is currently running in solar only mode, so it only consumes power when there's enough daylight. Once a battery is connected and it switches into hybrid mode, the standby losses are considerable. I've been told that some of the big inverters like this can be responsible for 2.4 - 4.8kW per day. I'm not sure why standby losses are not talked about like conversion losses are. I'm further investigating this avenue.
@@UpsideDownFork Wow, that sounds mad. Why would an invertor need to consume that much power each day just to run some batteries? I'm calling 'BS' on those figures; perhaps speak to the manufacturer directly and get the facts.
@timminsit you can find idle or standby consumption on some of the data sheets and also find some owners with home assistant who also monitor it, but it's not clear for most inverters. AC coupled battery systems like the Powerwall 2 do very well, iirc 420Wh per day. Victron appears to do even better than Tesla. Both of these need additional DC inverters for solar and then have conversion losses to consider as well. I've asked SunSynk to give me a figure for mine and I'm still waiting. I can't complete my sums without it! Forums and owners who have commented in my videos seem split on whether it's using as low as 2kWh per day or whether it's much, much more. Apparently it doesn't go into a standby mode like givenergy does for example. That's why givenergy owners can sometimes be seen complaining that their kit doesn't ramp up quickly enough to cover household loads whereas the SunSynk inverter is reportedly a lot more responsive, able to give a full 200A at any time, avoiding any grid draw. Like I say, I'm still doing my research so I can be sure before I share anything in a video.
Really interesting video. Is your system economically worthwhile, ie. are you achieving a zero bill over the year? I think in Australia, because of the uptake in solar, many people are now receiving very little for their exports. Are your calculations based upon receiving enough export offsets to make it work? My system requires overnight topup of battery during Oct-March to function, but I have no export facility.
The plan was to reach a zero bill for 2024. It looks like we'll just fall short. We also didn't have an EV when we started and didn't plan to get one but things changed when my wife crashed her Vespa. Definitely would have made it to a zero bill this year without the change to EV. I'm sure it won't be long until the export rates drop but I'll make the most of it until then.
I have the same Sunsynk inverter with a small Sunsynk (5.something kwh) battery. I've currently switched off the battery charging since it's costing money to maintain it with the lack of sunshine - where it comes into it's own is during the sunnier months since it allows me to use less from the grid and it evens out demand. This helps with seasonal offsetting. Given batteries are more affordable now compared to when I took the plunge, I was toying with adding an additional battery - I'm interested to see where you land in terms of brand and capacity, since I know you're going to have numbers to help explain your decision :)
@@UpsideDownFork Look, the Germans experimented on unwilling subjects. That's very wrong. But when it comes to zero carbon, we have people who want the policies. We should run an experiment where they get the policies implented in full, and others see how it works. Now you're most of the way there. So lets see how that would pan out. Flying. They get added to the no fly list. The little devil in me says, after they jet off long haul. They can Greta themselves home. Cars, electric only obviously. No trains, tubes because they use fossil fuels. Buses if they are electric or H2, and only fueled from a green supply. You've passed that. Gas? Cross check electoral register against gas supply, and the gas is disconnected. Then Green only tariffs, obviously. Plus a smart meter. From your video there was one period where you had to consume, but if there isn't enough green power, the click, you get a brown out. Oh, and no subsidies. They are bad. What's not to like about a big experiment on willing subjects? :-))
I’m very fortunate to have a very large south facing roof on my bungalow and I’ve put 34 x 435 W panels on it. 12.8kwh of batteries. And in the summer it produces four times the energy we use but in the winter, it’s completely different. Maybe a quarter to a third of what we need. So having the batteries charged up at night when the electricity is cheap, makes a big difference in the winter months. Only wish we had larger battery capacity because our heat pump uses a lot of energy when it’s cold.
Have you considered Flux for the summer months? It has good export rates and not awful import if you avoid 4-7pm. I've gone onto that from April to October for the last two years and have built up decent credit for winter, when I'm on Go.
Do have one figure. How much you finally electric bill , including standing charge for gas and electric. Without all the extra charts just a final bill.
Hi. Great sensible videos thanks. We only have a small solar panel setup of 2kw south facing panels so have the 9.5kwh battery. Battery has to be a no brainer as import at 6.7p/kwh with Eon Next Drive for our EV and battery and dishwasher and washing machine (load shift) to avoid daytime rate of 25p/kwh. We do export in summer after charging the battery up. For our system that’s the best setup. Wouldn’t that strategy also be the best / cheapest way to run your ASHP?
I've only had my 16 x 445w panels (S/SW facing by 10 degrees, in Scotland) since early October. Got a 5kW inverter and 9.5kWh battery from Givenergy. No issues so far. I'm on the Octopus Flux tariff just now. Not sure if it's the best for my needs.
Really interesting that the NW panels perform worse in winter. I'd have thought that with all the overcast weather they'd be matching the SE panels, so that's a really useful bit of research. We've got Dyness batteries with a Solis inverter, mostly because they were a lot cheaper than some of the competition and due to an installer who thought GivEnergy systems were lower quality. The system has worked OK, but the Solis app is too clunky to export for saving sessions, and is not compatible with Octopus Intelligent Flux. I don't think those drawbacks would ever balance out the extra cost of a GivEnergy battery though. Pylontech are similarly cheap batteries.
I have 15 kW of Puredrive batteries and I’ve been pretty happy with them. Total electric household so I reckon the sweet spot is roughly about 18 to 20 kW based on our usage profile. My original installer has swapped from Puredrive and is now installing both Duracell and Dyness. Says it’s just down to less issues. Price of batteries has dropped substantially so I would be looking at those that have been around a while and have great support and compatibility.
Another good video, I suppose one question is going to be what size battery. My situation is 5.8kw of panels and 15kwh of battery, my base load and normal usage in just over 7kwh per day , so in summer I have the option to switch to IOG and run the house on the battery and use the in feed option on the solax inverter to export all PV generated over the house load. In winter switching to cosy and using the 3 x charge slots. My consumption in winter is about 45kwh outside the cosy low rates, quite high. But I do have a 7.8kw heat loss property. I expect you will need a 10kwh battery and then cosy would work,
Similar picture for me, the bill has swung round, importing quite a lot with the heat pump being on all the time, generating and exporting very little, and a perfect storm with high Agile rates in the last week. The headline 99p rates were bad but my battery protected me from having to draw anything from the grid in the peak, but the high rates during the day when my battery SoC was being held for the peak meant I was having to grid import at 50-70p. Average import rate for Thursday 12th was 39p, but actually it wasn’t my highest daily import £ this winter - colder days in late November have cost me more. As long as its just the occasional day like that on Agile I can live with it, balanced by cheap import on other days
Eon Next Drive is 6.7p per unit between 00:00 and 7:00. I believe it's the cheapest way to charge a large storage battery with electricity to use during peak times.
@@robertredpath4817 it's was a great deal for battery owners.. I think they had a huge group of new battery customers and nipped it in the bud before they got overwhelmed haha
Fogstar (uk company) do DIY kits, they are half the price, you could even pay someone to wire them up & it would still be cheaper. I have 2 pylontec 4.8kw batteries but looking at getting the Fogstar to add to them.
Im getting my new solar battery installation next month. What do you think the best octopus tariff is for this setup. I have no EV or heat pump. Ive ordered a Sygenergy battery as recommended by my installer. Expensive but looks very nice and stackable with built in fire extinguisher!!!
Flux is best without EV, then you can export excess for high return in peak and have a good-ish low import at night. You'll need to set up the system to do this automatically to get the best benefit
Depends on what time of year. If you have enough battery capacity to see you through the day then Octopus Go for the winter. If you need to recharge throughout the day then Cosy. Depending on how much solar you have to export, flux may be best for summer.
Fogstar Seplos 16kwh kits were £1400, I have 3 of the 15kwh versions, All Grade A cells, top company, All energy bought from Tomato at 5p, battery, EV, HP etc 👍
@@UpsideDownFork yes it is via Octopus energy You'll need to have: • A compatible charger: a Wallbox Quasar 1 V2G charger • A compatible EV car: • A smart electricity meter to connect to • Permission to export energy to your local distribution network (aka a G99 certificate): contact the DNO (distribution network operator) for your area if you need one. • A schedule that fits: You'll need to be able to plug in for roughly 12 hours a day every couple of days, and charge less than 333kWh per month (equivalent to 1,084 miles of driving).
@@sbjchef Unfortunately that charger has been out of production for some time. Finding one second hand is difficult and expensive. They are also not known to be reliable.
I'm guessing you are getting the Fogstar 15.5kWh and going to then switch to IOG and get that average unit price down to 8p 😉 My last bill for 28th Oct to 27th Nov was £92.72 including standing charges (home + EV + charging battery). That was 888.0 kWh @ 7p and 54.1 kWh @ 25p so an average unit rate of 942.1 kWh @ 8.03p. Our export was only 81 kWh for £12.15 so a net bill of just over £80. This is without the gas cost which was £99.78, can't wait to get a heat pump! Pre charging the battery overnight in the summer should add 10+ kWh a day to your export payments by not needing to wait for the battery to fill up before starting to export.
£55 electric bill for November, on Intelligent with a battery, solar, EV and a heat pump. £18 of that is standing charge, and Octopus bill shows 8.17p/kWh average, but I think that's before VAT...
A battery really helps to offset more of your use to night rate. For the last 12 months we used a total 7,308 kWh for our home, 3,107kWh for the EV and 2,687.9kWh for our ASHP. General home use This was 2,754.2kWh Daytime and 10,349.1kWh of Night Rate. Solar Export was at 2391kWh Average night rate use of 79% That is with a Tesla Powerwall 2 and 7.56kWh solar PV over and E/W split roof.
I've not yet cleaned mine although I have been up there to inspect them up close. I intend to use wet and forget when necessary. Testing on other surfaces show extremely promising results.
Unfortunately by the time you get a compatible car, charger and DNO etc it doesn't work out cost effective at the moment. 30kWh leafs have the worst battery pack of any EV. One dodgy cell can kill it so easily.
Hi great post good pace with your info. I have a sunsynk system using 4 x 5.1kwh SSLB1 batteries. I opted for a full sunsynk system for ease of installation and trouble free coms connection between inverter and battery. The system work great. I fully charge at night on cheap rate and I have enough capacity to run my entire home for 24hr. You need to consider the max discharge rate on the battery mine will only discharge at 2.5kwh max to achieve 10kwh I needed 4 battery’s in parallel. Your inverter I think will need about the same to get the same power when running using battery alone. If you do upgrade and have batteries check the supplied coms cable the one I had was very stiff and caused the RJ45 socket to get dislodged form the inverter PCB board. Just something the consider. Good luck
@ I have 2 x 5kw sunsynk inverter running in parallel. I don’t know what the losses are. I also run my entire home from the UPS output from the inverters. I love the vary rare occasions we have a power outage 😆
On agile tariff, my average cost was 24.5 p/kWh in November due to the few days of high energy cost. I don't know how you have managed to keep this to 17p
Definitely was not easy. Heat pump off every day 4-7pm and I did quite a few slow cooker meals to avoid having the oven on during peak times too. Being able to charge the car mostly when it was cheaper really helped to bring the average down too.
@UpsideDownFork December is looking even worse for now with an average cost of 27p/kWh. When I back tested my usage with agile price last year, it was clearly showing cheaper even without changing my habits. Since on agile, even with the HP off during peak hours, it is not proven cheaper and that makes me wonder if the cosy tariff would not be safer
Looking further at your 8.8KW Sun Sync inverter. It’s directly compatible with Pylontech and many other 48V lithium batteries. You should be able to add the Fogstar 15.5KWh battery as its BMS can emulate Pylontech BMS. Get your solar guys (Dorset Solar Solutions) to take a look at Fogstar wholesale options. Then you can also get the VAT off the Battery’s. You should be able to add 31KWh (2 batteries) installed for 5-6K. The install for your existing inverter should be pretty straight forward. The other option is the Fogstar Rack Batteries. (Same BMS and heater) Although they are more expensive per KWh.
I'm thinking of building a system from scratch including the homes themselves. My initial idea is: 1 Use geothermal heat. 2 Use one industrial heat pump to supply 6 homes. 3 Use SIP panels, not brick. See the R value of brick - it is terrible. 4 Use underfloor heating. 5 Use a computer system to optimise all running parameters 6 Use solar tiles on the entire roof. We will also need an air conditioning system to prevent the build up of humidity. I think batteries are necessary as well to give the computer more options to plan the use of energy. They are so cheap now it is a bit of a no-brainer. We can gain a bit of an advantage by combining all six homes. It flattens out the usage rate so if one place is not using the solar in the summer another might be.
It's not AC you want. It is heat recovery mechanical ventilation. It is something UK must finally start learning about as it is just sad when whole world is using it with way lover humidity but UK doesn't... And many houses are easy to adopt it. I am going to install it in my bungalow along with capillary tube heating on the ceiling as well. Enough with radiators. Destroying the floor for underfloor heating would be too expensive, while I can simply roll out heating tubes on the loft between wood beams as my ceiling is made out of plasterboards now. Cover back with wool and call it a day... hopefully. Amazing stuff. Only exists about 50years on the continent....never seen in the UK I think...
@@havocchanel I think the way to do it with heat recovery of warm dirty air is to use a heat exchanger to take the heat from the exhaust air and dump it at the input of the heat pump which will be colder than the outside temperature hence giving greater heat transfer efficiency. A point about underfloor or even under ceiling radiators is you need efficient thermal contact with the room's air. If there is any insulation between the heating elements and the room air it will reduce the COP.
Hello, I am in the UK and have the exact same inverter as yourself, the inverter is one of the best purchases I have ever made and I have wired it up to exploit all of its many capabilities. Regarding batteries I would recommend looking at the Fogstar storage batteries, which I chose myself after extensive research into the subject - you can get a 15Kwh unit for a bit over £2000. You ideally want 2 of these for your specific setup, but it is almost trivial to expand should you only want one, they are compatible with the SunSynk inverter and have been running perfectly for over a year.
@@tomt_techman search for 'Fogstar Energy 15.5Kwh 48V Battery' the price was £2200 last week or so (perhaps black friday promotion) but is now £2500; still an excellent deal in my opinion, they also have smaller 5Kwh for around £1050
We have a Give Energy 8.2kwh battery, with 4.5kwh of solar and have had these in place for two years. The panels I feel really come into their own with a battery, enabling a complete 24hr cycle of free solar generated energy at the best of times. At the worst of times, no solar generation but a battery which can run the house on cheap overnight electricity all day. Also with a battery, I can charge my EVwith good solar generation, then when the sun hides behind a cloud, the battery maintains the charge until the sun comes out again.
Similar set up to me. We have the same inverter, but we have the 12kw Vaillant ASHP. We also have an EV and are on the Octopus Intelligent tariff. I've just added 2 X 15kwh grade a 314ah Seplos V4 kits from Fogstar which we charge off peak and they are excellent. So much so I've ordered a 3rd because even 30kwh (24kwh usable when discharging to 20%) doesn't quite cover our peak usage. Connects to the Sunsynk with no fuss and just works. Do it, you won't regret it!
We have 2 Seplos 16kWh DIY kit batteries from Fogstar, bought the second last week on offer for 1400 quid, and just setting it up now, game changer, potentially will get a third as we go into the spring, our system is 12.6kWp with an export agreement of 6.4kW, so we can generate loads of energy in the summer months, and would rather store it and export than let it go to waste (even with the 32kWh batteries)
I found that if I took expected lifetime production and the installation cost and converted to pence per KWH both for the solar system and batteries it becomes a lot easier to reason about and model in the existing tariffs. For example on average a KWH from the solar costs about 7p snd storing in the battery 8p. So about 15p for a stored KWH, how does thst compare for evening and night time power costs. I found that a battery pays off in about 3 years if its used through the summar to move power as well, if its just for power shifting in the winter it takes three times as long.
How about take down the NW pannel and set them up on the ground in the garden, or a S facing wall. I bet that would make a difference. Cost benifit of NW is pants.
My kids would find a way to smash them on the ground! 😁 If you think NW generation is bad, you'll be shocked at my next video which shows their generation over the course of the year!
We have 7 south and 6 north facing 450w panels, 9.5kwh Givenergy battery and an EV on intelligent Octopus go. 3 bed semi 1920's on gas central heating ( heat pump coming Feb 25 ) 488kwh of power used at a cost of £38.59. Gas 555kwh at £35 for November. Charge battery and car at 7p night rate, battery covers house until 11:30pm when cheap rate starts.
@UpsideDownFork Yes, I have been thinking about adding another because the pump would drain the 9.5 on a cloudy day quite quickly I would Imagine. Heat Geek have guaranteed us a cop of 3.6 @ 21C outside -2C. Alternatively, I may try and limit the output of the battery so it lasts the whole day and pay for the extra as I would not be paying the daily gas charge. I'm still generating almost 10kw on a sunny day here so Im hoping to only have a couple of expensive months.
For Batteries I’d go Powerwall 2 if you can. I’ve just bought an additional one for £5k installed as they are trying to sell off the old stock. I now have 27kwh of storage but the best bit is the in out power is 10kw so I never have to draw off the peak electric (some batteries are only 3.6kw in out and with your Heatpump on boiling the kettle will draw off the grid). The last octopus power hour (2 hours) I drew 36kwh of free electric into my car and the Powerwalls. On the turn down event I exported 9.9kwh in the hour which was worth £5.30 to me (£6 less the 70p it cost me to buy it). If all the Powerwall 2”s have gone get the 3 but I’ll bet the price will have gone back up.
@ my friend has just had his export renewal off Octopus and it says it’s not a 12month fixed rate of 15p anymore and could go up or down. (Which means down🤣).
Had batteries and solar since 2019 but what is available has changed massively in the last couple of years. Do the batteries save money ? Our average cost per kwh is 12p over the 12 months, excluding fit payments. We generate 9mwh and use about 7mwh of that with the batteries in place HOWEVER the place the batteries make a difference is in the winter months, where you import at cheap rate. Sigenergy looks like an interesting idea given they have now integrated a 22kw dc rapid charger and also support 3 phase. If I was starting again and they were around, they would be on my shopping list ! In summary, our current setup means a 2k a year power bill instead of 6k. Even with a battery, you will still export a bit of power.
I'm moving home (hopefully January) and looking to install the most panels I can - 28 - which will be 12.74kw. I wont have an EV, heat pump or battery to start with, but will most likely add these over time. Am I likely to export more than £1000 of electricity without having these? I read that if so it will be taxable. I would rather not have another complication to my tax return if possible.
You should speak to a tax adviser. Many people have been told that if you don't withdraw it from your energy company then you are not liable for any tax.
I have a new installation of 18x solar panels (450 kw) with a 2x 5.2 kw battery... I'm only getting less than 0.5 kw per day. Is this normal? 8kw sunsynk 8kw 3 phase inverter..
I have one 16kWh battery, we charge it at 0.085p for a few hours off peak, and that, along with the solar is enough to power the house through the remainder of the day and night, I have just bought a second 16kWh battery as our system will generate so much energy in the summer that I want to store it to sell back, we dont import any electricity in any peak period. Batteries are a game changer, our 32kWh of battery storage has cost £3100 from Fogstar, they are the Seplos DIY kit, of course there is also a need to have MPPT's and a hybrid inverter (our batteries are on the DC side), I think AC batteries are a little different set up
I love Victron energy products for battery storage if your looking for options. It gives you the flexibility to pick the batteries you want to use and expand the system over time. I would also suggest that battery prices are plummeting so rapidly at the moment that they could well be half the price in a years time, it could still be worth waiting.
I’m grateful if the PV inverter even starts up at the moment - let alone have any excess 😮 First day of actual sun today in December
I feel your pain! 😭
i only get 1-3kwh a day from
9kw worth of panels
Thanks!
You're welcome! Thanks for your generosity 😊
I'm convinced that battery is worth it. It gives you flexability: who knows what tarriffs will do in the future as more renewables come on stream. If you can store energy and charge a battery fast you will always be able to access the cheapest rate for all your power.
Currently a big enough battery enables you to make money even on days with no solar by buying cheap and selling high.
The absolute cheapest way to add a battery will be to buy raw cells and a case from direct from china. You can take some of the uncertainty out of it by purchasing from fogstar in the UK 15.12kWh for £1560 currently. You'll have to assemble it but it's not that hard and there is plently of help online. Down side is no extended warrenty but set against that, you built it so if it has an issue, you can fix it.
Thoes fogstar batteries cost £2500 to £3000 for 15kwh 8 year warranty
That's from their website anyway.
When I purchased my system I ran the numbers and buying cheap then selling high makes quite a big difference over a year. In my case it made the difference from not being worth doing to being just about worth it.
Seplos is an option if you want to build DIY yourself. Although personally I prefer £2K (Black Friday sale) for the Fogstar 15.5. UK warranty (8 year) and Support. Better BMS and Heater included. All this benefit for £440 each, and you don’t have to build them👍.
@@Burtis89The Fogstar 15.5 was £2k on the Black Friday sale. I’m sure they will be discounted again at some point. An installer could go the Fogstar wholesale route and then you will get the VAT off as well👍
Thanks! 😊
You cheeky little tease. Your two questions at the start are exactly the two questions I've been waiting for you to answer definitively! 😂
Thank god you've been publishing some banging videos in the meantime whilst I wait on the answer! 🎉
Loving the content as always.
When you do answer I'd like to see the option of battery with NO solar explored too. Is that the better option financially?
I suspect that with the way energy markets are the best hedge it's both battery and solar. Sometimes it's best to use what you generate, sometimes export rates are high, sometimes low. Sometimes you'll get a cheap overnight tariff, sometimes the gap between peak and off peak tariff will fall.
Market forces.
Need to be able to manage in all those circumstances but it's costly and the payoff may be too long.....
Cheers again from the great vids
Thank you for the support.
It would be unfair to draw any meaningful conclusion with only 11 months data! Haha!
See you in a few weeks!
Thanks for producing the video , solar edging towards the naughty list , looks like batteries are on the cards , you being you a deep dive into the reality of each battery make and not listening to the BS or R/S being the seasonal equivalent.
You bet
If you can add enough battery capacity to survive on mostly off peak energy, I would guess you'd be able to get your average price per kWh below 10p. Octopus Intelligent being the obvious tariff. I'm enjoying my recent switch to Tomato Energy, but we'll see how long it lasts!
@@robwalker864 yes, that's the plan 👍
We have 27kWh of battery storage and, on all but the coldest days, we can live off the octopus 7p rate.
@@crm114. Yeah 25 here and we're about the same. Although our general house load is too high and slowly eats away at it. The move to Tomato Energy has helped as it's 5p overnight and then I charge back to 100% for 2 hours in the morning at 14p
I'm averaging 9-10p on intelegent octopus go. Thats no solar, battery or heat pump. Just an Ev. Load shifting is the key.
Mine is well under 10p, even when I include the standing charge…
interesting stats and numbers. as others have said, especially when using a heat pump in the winter, a battery system will sort itself out in a few years, likely within warranty. an observation i have is that a battery is almost the inverse of the agile mentality y. with agile, youre gaming the system and timings where you can (and some batery inverters coupled with HA can do this too) but generally with batteries youre on ToU tarriffs, and using overnight rates.
for me the penny dropped whn i had an export rate: once youre exporting, batteries and solar are decoupled and its less about using what you generate, nd more about maximising the I/O equations. For minimising the bill, Solar gains are made from exporting at 15p as much as you can, and not importing when its 20+p, and likewise the battery gains are made through covering daily use with overnight power pricing.
My rule of thumb is, if you can cover 100% of your daily usage (for 90+% of days) in the winter (HP usage is going to massively challenge that!) thats the rigut amount of batery. rest of the year you can safely export that battery at a time that suits you for £££.
👍 sounds good
I have an old Nissan 24kw leaf pack that I have split down, reconfigured to a house battery, currently getting approx 17kw out of it
Oh, nice! Which inverter did you use? Was this difficult?
We're on Intelligent Octopus Go and the battery always beat out the solar as a result, as it lets us consume electricity at around 8.1p per kWh, according to home assistant our cost per kWh imported (when taking solar exports into account) has been 3.1p so far this year, which is pretty fantastic and is almost entirely down to the battery system and consuming almost no peak power at all.
I do find your NW roof experiment really useful, we have a small south facing roof, which has 5.8kwp of panels, but our north roof is 3x the size, part of me wonders if it's worth sticking a load of panels on there and accepting that they'll only run at 50% on average, which would be pretty good as we could effectively over double our array production
Thanks 👍
Just remember Fork is very much down South, so if you are mid or more north, adjust accordingly
Use your north facing roof but tilt the panels up so they are facing south the same number of degrees that you house is latitude north.
@@stuartburns8657 You'll probably be interested in this if you haven't yet seen it. A property in Newcastle.
ruclips.net/video/QAIYNrNbc78/видео.html
@@DavidBridgman-hy8ib I'm not sure you'll get an engineer to sign off on that one.
If you go for battery there is something to be aware of - most hybrid inverters pull around 100W to 150W pretty much all the time. That means you could be losing up to 3.6kWh per day simply to run the inverter.
The only hybrid inverters I know of that don't are Victron at around 30W - 50W for most of their units. As they are designed mainly for off grid use, they are highly optimised for efficiency. The down side is cost. Victron are more expensive so you need to run the numbers to see if that efficiency gain is worth the extra cost.
Yes! Standing losses are a real concern as I've heard my SunSynk 8.8kW is a bit of a beast in that area!
My victrom multiplus 2 48v8000kVa only draws minimum 18 - 20w
Yes! My off grid cabin 3K Victron Multiplus draws 10W at idle.
You may have trouble finding people to install a Victron system. Here in Canada a friend met with the excuse that Victron wasn’t CSA approved.
From my experience this year with GivEnergy 9.5kWh battery and hybrid inverter, I can tell you that the inverter draws about 36W and the battery about the same again.
Looking on Power Forum the Sunsync has a Grid Trickle Feed setting somewhere, which in their area defaults at 50w but advice is to drop it to 20w and check that Electic Meter is still happy as it can trip it if too low.
I'd be interested in the outcome as planning a setup similar to @UpsideDownFork 😊
So far this year we have imported 9000 kWh, 99% of it at 7p overnight and exported 6000 kWh at 15p so well happy with that, two EVs and a heat pump to power with two powerwalls providing power all day long, avoiding the horrific agile prices seen this week, but hey ho they will be back to normal for you next week!
That is impressive!
@@UpsideDownFork For just short of 3 years I have had a very similar solar set up to you a split of 6.5kw, just over 2 parts NW to 1 SE, 13 on the back and 6 on the front of the house, I also have a Tesla Powerwall 2. I will be honest if I had my choice again I would have had 2 Powerwalls fitted and left the solar panels in the shop. We are on the Octopus intelligent Go tarriff, were we charge the battery, have a Cupra hybrid, use the washer, the dryer and a couple of ceramic electric radiators during the 6 hour 7p cheap rate.
The October to March period the panels are as much use as a chocolate fire guard, even March to October has been a big disapointment this year as it just seemed to rain every day this year. As an example 25th of October to 25th November we exported £5.16 an average of less than 1kw a day produced.
I am thinking of going in a different direction to you regarding heating and hot water as we still have a large floor standing combi boiler I would like to get rid of and I have read so many conflicting reports regarding heat pumps. I am looking at a Klover 120 pellet stove in the kitchen coupled to a unvented cylinder in the garage, I will heat the hot water in the cyinder during the cheap rate when we aren't using the stove in the warmer months.
If you can afford it get a Tesla Powerwall 3 fitted, supposed to be even better than the 2 and the 2 has been brilliant so far for us. All the best which ever you choose.
I have a 9.5kwh battery and even in November and December I manage to export from the battery at 15p most days and recharge at 7p, so with a Powerwall you should be able to do that I would think ?
I have a 48v pack from a forklift. It gives me 70kwh of storage. Yes it’s slightly bulky, but it’s not sitting in my living room at the end of the day.
Connected to a Sunsynk 5.5kw, keeps me off grid for 8 months of the year, and off peak for the remaining. Minimal maintenance, and no worries about cold weather like the lithium. At £28per kWh of capacity you will not find better 👌🏻
Big old lead acid thing?
How large are we talking here?
@ Big old, tried, true and tested IFLA 😉
Takes up the footprint of a standard pallet. No gimmicks, just straight forward energy storage that does exactly what it says on the tin 👌🏻
@@dannyg2325 Unfortunately I don't have a cubic metre to spare until one of the kids leaves home!
Thanks for putting this out, glad to see a fellow energy geek. Adding in a battery would give you a buffer for that agile pricing. The real cost is to the family as you will have another set of factors to manage day to day😂
Ha! Very true.
It was inevitable you’d eventually end up with a battery system particularly with the heat drawing so much energy in winter, but credit to you for seeing out the experiment.
There seems to be so much more choice with home batteries now you will no doubt have fun choosing between them. My Giv Energy hybrid system has been faultless and has served me well, so I have nothing but praise for them. Good luck with your choice.
Thank you! I'm fortunate to have a complete year of heat pump and solar data. From that I now know that 17.5kWh is my ideal battery size. Any more than this I'll encounter diminishing returns quite dramatically, but 15-20kWh seems the sweet spot for my home and heat pump load.
From experience, Givenergy is nice with the API and octopus integration and excellent customer service. The all in one is great, the true size is within your range. There are cheaper options. A simple hybrid inverter might be the best bet
@@UpsideDownFork Remember, you don't need to factor battery size for the duration of the cheap slots, if you are using the ASHP and charging battery/car during a presumed 6 or 7 hrs of cheap slots, the battery only needs to be big enough to cover the remaining 17-18 hrs.
I've moved from agile to octopus cosy now the fixed cheap rate is great and running the heating/water in these hours I've found it to be very good value
Good move
New subscribers.
Great video. Lots of effort put in! Thanks.
Thanks and welcome 😁
My single pylontech battery with a minuscule usable storage of 3.4kWh has saved me more money over the year than the amount I made from exporting excess energy from my 7 solar panels. I am on octopus agile, and my strategy has been to fill up the battery overnight as long as the rate was less than the fixed export rate of 15p/kWh. That way I have started exporting quicker if it was sunny, or not used grid energy on those dark nasty days with no generation. I’m going to double up with a second pylontech next year as in the winter the light is gone by 3pm and the battery is empty by about 8pm most nights. This month even with those mad days of 99.9p/kWh during the peak periods on agile my average rate per kWh is under 14p and according to Octoprice I have saved over £40 for my import over what I would have paid on the standard variable.
Nice, that sounds good!
I would be looking at the max kWh daily usage and trying to get close to that with battery storage so you can charge up on cheap, green electrons and discharge when it’s expensive and dirty.
If this seems like too much, make sure the batteries can force-discharge onto the grid because then you can discharge just before off peak starts and make more money exporting than you paid for the power in the first place. You’re then helping to balance the grid and making a tidy profit to boot!
My max kWh consumption in one day this year is 82kWh but 40ish of that was car charging and approx 10-15 was further load shifting on the cheap rate.
30kWh would be great but anything over 15 will not see great returns as the first 15 will. Diminishing returns are definitely a big factor when choosing the optimal battery size.
Really look forward to your video,s but would ask if you could not race your mouse over screen so fast as I end up like a cat trying to keep an eye on its prey! I found your video on the Vaillant controller excellent and it’s given me more confidence in its use. Keep up the excellent Vidoe’s.
Apologies. ADHD tendancies? Guilty here!
Great video. I held off on solar until I felt happy with battery tech. A year later and I pulled the trigger getting my installation in early September. I went with Sigenergy hybrid inverter and batteries. Let me know if you want to discuss my experience so far.
Early sig adopter here too..m great piece of tech. Currently riding agile in A.I mode. Totally hands free. Really impressed with how it's handled this awful weather
Sigenergy looks great 👍
I saw 100p kWh 12-12‐2024 6pm on Octopus Agile!
That's 6.6x what they pay for export at 15p.
Having a cooked dinner will become the status symbol of wealth!
😂😁
The savings from the use of the battery during the last year was less than £250. We are on intelligent go, 2 ev’s, gas boiler(stays till it expires), 7.5kw pv.
At current energy prices the battery will never pay for itself
That’s interesting but not surprising, I do see some people gaming the system a bit charging overnight and exporting the charge back to the grid but to me at least that doesn’t really seem to be a good idea, goes against the point of having battery’s to me at least.
Interesting calculation and probably not far from my own use case.
im offgrid on a plot and saves that every other month
Thanks for sharing this experiment and I understand why you jumped ship a month early. Seriously though, December is looking even worse than November for Agile rates with a couple of miserable, windless days already. Let's hope for some more named storms when the electricity price drops to zero (or better)! We have Pylontech batteries which are modular and easy to expand in 2.4kWh increments to get the size you want. Maybe you can save money by getting a smaller battery than you think you need and adding to it later, if necessary? They're also compatible with a wide range of inverters. With any battery system, you'll lose about 10% in conversion losses so factor this in. However it makes gaming the system with Octopus Agile so much easier and more effective. Looking forward to seeing how you get on next year.
Thanks for the feedback!
1% eh, well great video, so you admit you lost the battery battle… I thought you may! I have been riding the export £ buffer out same as you, November finally killed it… Data shows this year (so far) I am up to 18MWh usage with 32% from the grid, Now I still have a DFS credit with Octopus of over 110k points which I could cash in… but DFS rates suck in comparison this time round in 2024, so not something to rely on in the future!
I have never used peak rate energy, not once in the last 12 months and am rinsing that octopus cheap rate every night… I fully expect to be able to ride this out till the sun returns.
Other than charging cars and batteries I do exactly zero load shifting to anything else in the home. Time is money also and no one seems to factor the cost of messing about with devices each month. Look forward to seeing your next challenge!
Nice!
Very true about not factoring in time messing with stuff!
I have a similar panel array but with 25kw of batteries, and also on agile. My heart goes out to you last week being crippled when rates hit 99p last week, also stayed high for many hrs, with no batteries. they are easy to DIY install and you can escape VAT as well.
I use 5 X4.8kw pylontechs and we can buy them for £930 each right now. Can get even cheaper with fox,
oohhh and looks like power is free tomorrow night with agile. Time to fill my boots again.
Thanks for sharing
We've bought 2 x 15kw seplos DIY batteries for the same inverter as you, being installed tomorrow. First time solar, and I decided the main function of the battery has to be saving money, hence the DIY battery packs. Hopefully this is a productive journey!
I don't think you'll go wrong with that option! 👍
Oh, Also, full house backup with Victron Multiplus ii inverter. 5K limited to 50A. The 8, 10 and 15K inverter has 100A changeover switch.
Thanks 👍
I have 8kW Solar and a Givenergy All In One. Works well and full automatic switch over for powercuts as well as 6kW feed. I would have bought 2 at install but they did not have it working then (very slow to get it available) though it now is. However, filling the battery & EV overnight on the 7p rate (IOG) and then exporting all solar excess at 15p I very seldom run out of battery. Though I do not have a heat pump yet until Gas boiler dies.
Only very few days where I need the 23p rate at all and that is often for a kWh at 10pm until the cheap rate kicks in again at 11:30pm. Hence glad I did not get the 2nd battery.
Also agree with another post watch out for conversion losses - I think mine is well over 15% in & out.
Thanks for commenting!
Love all the data. On the EV charts, would be interesting to also include the miles with the kwh so viewers can transpose to their use for an approximation. Maybe in future?
I understand its all circumstantial, many variables given different location, house, house usage/EV driving style or type of drive/ house/hp usage, kit itself, etc, though it all provides a sort of approximation. Especially by the time you see similar charts from a few different people. Cheers
Thanks for the feedback!
ev drivers in summer ought to do nightshifts, allowing any solar excess during the day to be car stored
or just keep on ignoring the fact of Carbon Shifting, and feel OK until vehicle disposal. great vid
That's an interesting though i've never come across!
It's just a given that we need back up power, that can be solar, mains,battery, whatever but redundancy is just an obvious requirement. panels are pretty much there to do both jobs if used with batteries and go together like bread and butter
Well said.
Like you I am using seasonal offset, it was great to generate 16.33kWh today with a couple of hours of sun finally!
Great to hear! only 4.5 for me!
Another great video, but interested how you show usage and cost on octopus as all I see is the usage in kw and no option to toggle to £’s
Shows that on the app for me, but not on the website.
Bizarre as cannot get it to display or either 🫣
Love the alloys on the mg5
Thank you!
Hi, keep up the videos they are great. Where do you get the solar forecast to compare with your actual generation? Many thanks
Open solar. You can do the same with PVGIS and several other tools.
When did you get the MG? I have not seen many of your vids in a while. I must have missed it, how is it?
@@letsgoelectriclge1320 ruclips.net/video/IUHnACm1iLg/видео.html
Another potential gain when installing an oversized battery system on agile tariff is the option to offload all your spare capacity to the grid at peak evening rates knowing you can then help the grid out again later by putting in a very large charge if the power rates drop to low single figs or even negative. This way your spare power can provide additional income on top of any solar exported, to some multiple ratios of power exported verses imported.
With more turbines being commissioned daily (new uk wind generation record on 18th Dec), and with twice the amount planned low rates every time the wind blows will become more regular. Export power rates to households are being given at best break even rates. Always DIY install batteries..so easy to do.
Thank you! 👍
Fogstar have some decent DIY kits available (based on Seplos BMSes). The first generation Seplos Mason (horizontal batteries) are not so convenient because of their very specific electrical connectors.
Thanks 👍
I have Tesla power wall and on octopus intelligent. I put second powerwall in to cope with heat pump and this keeps my average tariff about 8 p . Interested to see which tariff you go for . Thanks for content 🎉
2 powerwalls would be the dream!
If you can generate excess from your solar, getting a battery will help store some of the excess to use instead of using from the grid and offset. That way peak power can compensate from battery instead of peak grid rates
Yes, that's the plan.
Total Imported 1253.80kwh for £96.02 Exported 138.52 for £20.78 Heatpump was 272kwh cost £19.04 Cars took 653.5kwh cost £45.75 Ripple saving £19.23 (5.2kw solar south facing - 2x Powerwall 2’s and a Dakin 4kw Heatpump).
Very nice!
Do you use a generic forecast for your system, that is the same for every year, or is it generated for and specific for each year? Where do you get your forecast from?
This one is generated by open solar. It takes average historical data for my area.
You can generate your own pretty easily in PVGIS.
I had my Agile bill in today: average import rate was 9.30p/kWh; roughly 400 kWh consumed.
My setup:
-8.5 kW southern facing array, with shading from trees to the east
-SolarEdge Optimisers
-1x Powerwall 2 battery
-No Heat Pump (gas boiler)
-No EV
-Electric cooker
-Two electric heaters (used only when Agile rate is lower than gas unit price)
-Immersion and Eddi to supplement gas hot water
Solar production for November was down 10% from last November, which was better than expected from what was a miserable month, but a late burst of sun brought some respectability.
This is the first month since March where my exports haven’t covered both my import and standing charge - Flux from late February to early October; Agile and fixed export since then. But export still covered about half the cost of import and standing charge so not too much of my summer credit was needed to cover the shortfall. My exports are helped a lot by the Powerwall discharging stored energy ahead of lower Agile import rates, when the Powerwall then recharges, allowing me to pocket the difference between the 15p export and whatever rate Agile is charging that evening/morning to recover the exported energy.
Wow, you are doing well!
@@UpsideDownFork Thanks; the battery has been such a key part of this for us, it'll be fascinating to see how your experience contrasts with your current data.
I would think pylontech would be top of the tree for battery? You can rack mount them and easily add more. They also seem very well priced at 1.3 k for 5 kWh. Thanks for the vids, been watching all year!
Nice, thank you!
Yes, I will be doing some digging into pylontech for sure.
Sigen battery system is excellent but you have your inverter already and I haven’t checked on their compatibility with others. But as a whole house modular back up system it is impressive .
After only a few days in the current gloom I concluded battery storage would win over solar with the caveat that you obviously need solar in the event of a grid disaster .
@@pmb9172 thanks. I'm calculating my system to cater for the best whole year, rather than a few days or seasons.
That Sigenergy stuff looks fantastic 👍
Did play with the idea of charging batteries at the 7p of peak octopus rate intrested in seeing how you get on keep up the good work
Thank you!
Thanks for the update. I have seen which tariff you are on already, but interested to see which battery you go for. Will it be a smaller battery to get past agile peak, or a larger one to last all day on an EV tariff?
We shall see! Coming soon
Great to have all that data. I have a Growatt Inverter, which I think has a port for a modem but not sure. Does anyone know if I can just plug that in? Also, our Smartmeter had stopped transmitting since January. British Gas say they are on it, but it takes ages. Also means that I can't use any of these smart tariffs.
Do you know what model it is?
A few observations / comparisons.
You may not have been using the car more, it may just be the cars efficiency dropping as it got much colder. There will definitely be at least an element of that. Also lots of short trips are less energy efficient than fewer longer trips and thats more likely this time of year.
I have 20 panels all s facing but 8 in shade part the day so almost the exact opposite set up to you in terms of panels and direction
In November i exported 198k for a grand total of £30. (also on Octopus FE)
Actual solar production was 271k. Essentially the first 3k a day of my solar ends up going into the battery there seems to be no way of stopping that.
If i could be bothered i could force export that every day after the suns gone down but its too much hassle and it would probably only save maybe £50/year (because although id be exporting at 15p id be importing at 26p for that hour
My whole house (gas/electric) for Nov was £119 plus another £24 for the car (344kWh@0.7p). Actual bill for the month after export was £118.
I'd agree with your comments on the EV being less efficient.
I have an MG5, and the efficiency drops about 40% when using heater, wipers, lights in cold weather.
The drop off is pretty stark below 6-8 degrees.
I use a mechanical dehumidifier to reduce the need for demisting.
The MG5 is the "dampest" vehicle I've ever owned.
That is probably part of it.
I need to pay closer attention to mileage. My wife mostly drives the car.
@ the wipers and lights will be irrelevant. It's the heater.
@@Joe-lb8qn I didn't say they were drawing equal power.
2 x 55W headlights is not irrelevant.
@@UpsideDownFork the face-lift uses a heat pump, so less of an issue.
I believe the short range uses a different battery chemistry, which copes better at lower temperatures.
What % rate do you use for payback period calculations. Loss of intrerest on money you have (3.5%) or mortgage rate? I dont know if you have heat recovery systems but I consider they work particularly well in an electrically heated house.
ROI calculations coming soon in a dedicated video!
I've briefly looked at MVHR. I've been told that our house is too leaky to be suitable but haven't dug any deeper.
I don't have any solar, batteries or heat pump, but if I did go electric, I'd just buy a battery.
Tomato Energy is only 4.,7p from 00:00 to 06:00, 12p from 9:30 to 11:30 and 22:00 to 24:00. Otherwise 22p.
Easier installation and quicker payback time.
Thanks 👍
About the NW roof, I'm very interested as it's our best bit of roof. In midwinter the sun gets up less than a third of midsummer (still only 60°!), the day is of course shorter (less than 8 hours) and the sun sets much further south. All of which means bugger all light. Add the overcast December and I think it will be very poor, however you have shown it does generate a good whack year round.
The pitch of the roof is very important. Around 30 degrees is good.
Yes, as said, a shallow pitch is best for a north facing roof. Ours produces amazing figures in the summer months, frankly unbelievable the amount of generation we got from them in May, June & July.
I think you should stick with Agile (use the grid as a giant seasonal battery) and get a battery that is just big enough to cover your needs during the 4-7pm peak.
That's been my working assumption for many months. Basic calculations show that this is clearly the best financial strategy.
The challenge with that is that my hybrid inverter is currently running in solar only mode, so it only consumes power when there's enough daylight.
Once a battery is connected and it switches into hybrid mode, the standby losses are considerable.
I've been told that some of the big inverters like this can be responsible for 2.4 - 4.8kW per day.
I'm not sure why standby losses are not talked about like conversion losses are.
I'm further investigating this avenue.
@@UpsideDownFork Wow, that sounds mad. Why would an invertor need to consume that much power each day just to run some batteries? I'm calling 'BS' on those figures; perhaps speak to the manufacturer directly and get the facts.
@timminsit you can find idle or standby consumption on some of the data sheets and also find some owners with home assistant who also monitor it, but it's not clear for most inverters.
AC coupled battery systems like the Powerwall 2 do very well, iirc 420Wh per day.
Victron appears to do even better than Tesla.
Both of these need additional DC inverters for solar and then have conversion losses to consider as well.
I've asked SunSynk to give me a figure for mine and I'm still waiting. I can't complete my sums without it!
Forums and owners who have commented in my videos seem split on whether it's using as low as 2kWh per day or whether it's much, much more.
Apparently it doesn't go into a standby mode like givenergy does for example. That's why givenergy owners can sometimes be seen complaining that their kit doesn't ramp up quickly enough to cover household loads whereas the SunSynk inverter is reportedly a lot more responsive, able to give a full 200A at any time, avoiding any grid draw.
Like I say, I'm still doing my research so I can be sure before I share anything in a video.
Really interesting video. Is your system economically worthwhile, ie. are you achieving a zero bill over the year? I think in Australia, because of the uptake in solar, many people are now receiving very little for their exports. Are your calculations based upon receiving enough export offsets to make it work? My system requires overnight topup of battery during Oct-March to function, but I have no export facility.
The plan was to reach a zero bill for 2024. It looks like we'll just fall short.
We also didn't have an EV when we started and didn't plan to get one but things changed when my wife crashed her Vespa.
Definitely would have made it to a zero bill this year without the change to EV.
I'm sure it won't be long until the export rates drop but I'll make the most of it until then.
I have the same Sunsynk inverter with a small Sunsynk (5.something kwh) battery. I've currently switched off the battery charging since it's costing money to maintain it with the lack of sunshine - where it comes into it's own is during the sunnier months since it allows me to use less from the grid and it evens out demand. This helps with seasonal offsetting. Given batteries are more affordable now compared to when I took the plunge, I was toying with adding an additional battery - I'm interested to see where you land in terms of brand and capacity, since I know you're going to have numbers to help explain your decision :)
Thanks for commenting. An update will be coming pretty soon!
We need greens to be on a green register with smart meters.
Then when the sun doesn't shine etc, click the smart meter kicks in.
I think it's probably for the best that I don't understand this comment.
@@UpsideDownFork Look, the Germans experimented on unwilling subjects. That's very wrong.
But when it comes to zero carbon, we have people who want the policies. We should run an experiment where they get the policies implented in full, and others see how it works.
Now you're most of the way there.
So lets see how that would pan out. Flying. They get added to the no fly list. The little devil in me says, after they jet off long haul. They can Greta themselves home.
Cars, electric only obviously. No trains, tubes because they use fossil fuels. Buses if they are electric or H2, and only fueled from a green supply. You've passed that.
Gas? Cross check electoral register against gas supply, and the gas is disconnected.
Then Green only tariffs, obviously. Plus a smart meter. From your video there was one period where you had to consume, but if there isn't enough green power, the click, you get a brown out.
Oh, and no subsidies. They are bad.
What's not to like about a big experiment on willing subjects?
:-))
I’m very fortunate to have a very large south facing roof on my bungalow and I’ve put 34 x 435 W panels on it. 12.8kwh of batteries. And in the summer it produces four times the energy we use but in the winter, it’s completely different. Maybe a quarter to a third of what we need. So having the batteries charged up at night when the electricity is cheap, makes a big difference in the winter months. Only wish we had larger battery capacity because our heat pump uses a lot of energy when it’s cold.
Nice! You could say I'm green with envy!
Have you considered Flux for the summer months? It has good export rates and not awful import if you avoid 4-7pm. I've gone onto that from April to October for the last two years and have built up decent credit for winter, when I'm on Go.
Good strategy. I did do some basic modelling and at the time Agile worked out marginally better for me but of course the risk is a lot higher.
Will you (or have you) back test to see what the costs would have been if you’d switched from Agile to Intelligent around mid-October?
Yes. That was approx the tipping point for me and my usage.
Do have one figure. How much you finally electric bill , including standing charge for gas and electric. Without all the extra charts just a final bill.
@@sun-sea-solar I will do, when we get to the end of the year 👍
@UpsideDownFork cheers. My head scrambled by all the figures you have 😂😂
Hi. Great sensible videos thanks. We only have a small solar panel setup of 2kw south facing panels so have the 9.5kwh battery. Battery has to be a no brainer as import at 6.7p/kwh with Eon Next Drive for our EV and battery and dishwasher and washing machine (load shift) to avoid daytime rate of 25p/kwh. We do export in summer after charging the battery up. For our system that’s the best setup. Wouldn’t that strategy also be the best / cheapest way to run your ASHP?
Yes, absolutely.
We load shift as much as we can, including the heat pump.
New to your channel , subbed and enjoyed a very informative video .
@@Joe-fx9yj thanks for commenting and subscribing!
A brilliant video coming soon showing the conclusion of NW vs SE panels using my 2024 data 👍
I've only had my 16 x 445w panels (S/SW facing by 10 degrees, in Scotland) since early October. Got a 5kW inverter and 9.5kWh battery from Givenergy. No issues so far. I'm on the Octopus Flux tariff just now. Not sure if it's the best for my needs.
Thanks for commenting. Flux doesn't look great for winter but brilliant for summer.
Really interesting that the NW panels perform worse in winter. I'd have thought that with all the overcast weather they'd be matching the SE panels, so that's a really useful bit of research.
We've got Dyness batteries with a Solis inverter, mostly because they were a lot cheaper than some of the competition and due to an installer who thought GivEnergy systems were lower quality. The system has worked OK, but the Solis app is too clunky to export for saving sessions, and is not compatible with Octopus Intelligent Flux. I don't think those drawbacks would ever balance out the extra cost of a GivEnergy battery though. Pylontech are similarly cheap batteries.
Thank you!
I have 15 kW of Puredrive batteries and I’ve been pretty happy with them. Total electric household so I reckon the sweet spot is roughly about 18 to 20 kW based on our usage profile.
My original installer has swapped from Puredrive and is now installing both Duracell and Dyness. Says it’s just down to less issues.
Price of batteries has dropped substantially so I would be looking at those that have been around a while and have great support and compatibility.
Thanks for sharing
Another good video, I suppose one question is going to be what size battery. My situation is 5.8kw of panels and 15kwh of battery, my base load and normal usage in just over 7kwh per day , so in summer I have the option to switch to IOG and run the house on the battery and use the in feed option on the solax inverter to export all PV generated over the house load. In winter switching to cosy and using the 3 x charge slots. My consumption in winter is about 45kwh outside the cosy low rates, quite high. But I do have a 7.8kw heat loss property. I expect you will need a 10kwh battery and then cosy would work,
Thanks! Quick sums show that around 15kWh looks ideal.
@UpsideDownFork straight to the frogstar 15kwh battery pack
Similar picture for me, the bill has swung round, importing quite a lot with the heat pump being on all the time, generating and exporting very little, and a perfect storm with high Agile rates in the last week.
The headline 99p rates were bad but my battery protected me from having to draw anything from the grid in the peak, but the high rates during the day when my battery SoC was being held for the peak meant I was having to grid import at 50-70p. Average import rate for Thursday 12th was 39p, but actually it wasn’t my highest daily import £ this winter - colder days in late November have cost me more.
As long as its just the occasional day like that on Agile I can live with it, balanced by cheap import on other days
Good perspective! Big picture thinking is definitely needed for these things.
Eon Next Drive is 6.7p per unit between 00:00 and 7:00. I believe it's the cheapest way to charge a large storage battery with electricity to use during peak times.
Just a note you must have an electric car to join now. As of last week I believe
That’s an unfortunate change if true, their tariff was great in that it suited home storage battery owners as well as EV owners
Odd that they changed it? But yes that's what I'm on with pylontech 4x5kw packs. Sub £1000 per 5kw pack and they stack many units without a hub
@@robertredpath4817 it's was a great deal for battery owners.. I think they had a huge group of new battery customers and nipped it in the bud before they got overwhelmed haha
@ That’s a good price, and you can upgrade and extend them yourself unlike my GivEnergy battery system ☹️
With batteries, if you were starting now, would you consider a bi-directional charger to use your EV in a V2H solution?
@@paulnewman2000 if there were any commercially available, I would have got one already.
It appears that we are still a few years off.
You might have 4 sunny hours today 🤓. I am hoping to get some power in the battery for a change. Monday is looking pretty good as well.
I also had a warranty replacement SE optimiser fitted yesterday after only 7 months 😢
Yes, finally some sun!
Fogstar (uk company) do DIY kits, they are half the price, you could even pay someone to wire them up & it would still be cheaper. I have 2 pylontec 4.8kw batteries but looking at getting the Fogstar to add to them.
Thanks! 👍
Im getting my new solar battery installation next month. What do you think the best octopus tariff is for this setup. I have no EV or heat pump. Ive ordered a Sygenergy battery as recommended by my installer. Expensive but looks very nice and stackable with built in fire extinguisher!!!
Sigenergy batter....
Flux is best without EV, then you can export excess for high return in peak and have a good-ish low import at night. You'll need to set up the system to do this automatically to get the best benefit
Depends on what time of year.
If you have enough battery capacity to see you through the day then Octopus Go for the winter.
If you need to recharge throughout the day then Cosy.
Depending on how much solar you have to export, flux may be best for summer.
Fogstar Seplos 16kwh kits were £1400, I have 3 of the 15kwh versions, All Grade A cells, top company, All energy bought from Tomato at 5p, battery, EV, HP etc 👍
Thanks for sharing
do you have an ev to grid connection allowing you to use your ev battery for home storage, available from Octopus energy in the UK.
Not available in the UK: ruclips.net/video/hpxPaY_ghb8/видео.html
@@UpsideDownFork yes it is via Octopus energy
You'll need to have:
• A compatible charger: a Wallbox Quasar 1 V2G charger
• A compatible EV car:
• A smart electricity meter to connect to
• Permission to export energy to your local distribution network (aka a G99 certificate): contact the DNO (distribution network operator) for your area if you need one.
• A schedule that fits: You'll need to be able to plug in for roughly 12 hours a day every couple of days, and charge less than 333kWh per month (equivalent to 1,084 miles of driving).
@@sbjchef Unfortunately that charger has been out of production for some time. Finding one second hand is difficult and expensive. They are also not known to be reliable.
@@sbjchefcan you name any V2G cars available in the UK?
I'm guessing you are getting the Fogstar 15.5kWh and going to then switch to IOG and get that average unit price down to 8p 😉 My last bill for 28th Oct to 27th Nov was £92.72 including standing charges (home + EV + charging battery). That was 888.0 kWh @ 7p and 54.1 kWh @ 25p so an average unit rate of 942.1 kWh @ 8.03p. Our export was only 81 kWh for £12.15 so a net bill of just over £80. This is without the gas cost which was £99.78, can't wait to get a heat pump! Pre charging the battery overnight in the summer should add 10+ kWh a day to your export payments by not needing to wait for the battery to fill up before starting to export.
No spoiler alerts! 😁
£55 electric bill for November, on Intelligent with a battery, solar, EV and a heat pump. £18 of that is standing charge, and Octopus bill shows 8.17p/kWh average, but I think that's before VAT...
Brilliant! Great work 👍
A battery really helps to offset more of your use to night rate. For the last 12 months we used a total 7,308 kWh for our home, 3,107kWh for the EV and 2,687.9kWh for our ASHP.
General home use This was 2,754.2kWh Daytime and 10,349.1kWh of Night Rate. Solar Export was at 2391kWh Average night rate use of 79%
That is with a Tesla Powerwall 2 and 7.56kWh solar PV over and E/W split roof.
That is good going, well done!
One question to ask, do you wash your solar panels? If so, do you use a company to do it or do it yourself?
I've not yet cleaned mine although I have been up there to inspect them up close.
I intend to use wet and forget when necessary. Testing on other surfaces show extremely promising results.
Would be great if you could secure a vehicle to grid setup instead of a battery, I saw a 30kw leaf go at auction for £1800
Unfortunately by the time you get a compatible car, charger and DNO etc it doesn't work out cost effective at the moment.
30kWh leafs have the worst battery pack of any EV. One dodgy cell can kill it so easily.
Hi great post good pace with your info. I have a sunsynk system using 4 x 5.1kwh SSLB1 batteries. I opted for a full sunsynk system for ease of installation and trouble free coms connection between inverter and battery. The system work great. I fully charge at night on cheap rate and I have enough capacity to run my entire home for 24hr. You need to consider the max discharge rate on the battery mine will only discharge at 2.5kwh max to achieve 10kwh I needed 4 battery’s in parallel. Your inverter I think will need about the same to get the same power when running using battery alone. If you do upgrade and have batteries check the supplied coms cable the one I had was very stiff and caused the RJ45 socket to get dislodged form the inverter PCB board. Just something the consider. Good luck
Thank you! Valuable info.
Which size inverter have you got and do you know what the standby losses are?
@ I have 2 x 5kw sunsynk inverter running in parallel. I don’t know what the losses are. I also run my entire home from the UPS output from the inverters. I love the vary rare occasions we have a power outage 😆
On agile tariff, my average cost was 24.5 p/kWh in November due to the few days of high energy cost.
I don't know how you have managed to keep this to 17p
Definitely was not easy. Heat pump off every day 4-7pm and I did quite a few slow cooker meals to avoid having the oven on during peak times too.
Being able to charge the car mostly when it was cheaper really helped to bring the average down too.
@UpsideDownFork December is looking even worse for now with an average cost of 27p/kWh.
When I back tested my usage with agile price last year, it was clearly showing cheaper even without changing my habits.
Since on agile, even with the HP off during peak hours, it is not proven cheaper and that makes me wonder if the cosy tariff would not be safer
Looking further at your 8.8KW Sun Sync inverter. It’s directly compatible with Pylontech and many other 48V lithium batteries. You should be able to add the Fogstar 15.5KWh battery as its BMS can emulate Pylontech BMS. Get your solar guys (Dorset Solar Solutions) to take a look at Fogstar wholesale options. Then you can also get the VAT off the Battery’s. You should be able to add 31KWh (2 batteries) installed for 5-6K. The install for your existing inverter should be pretty straight forward. The other option is the Fogstar Rack Batteries. (Same BMS and heater) Although they are more
expensive per KWh.
👍 Thanks. This has definitely been a strong consideration for a while.
I'm thinking of building a system from scratch including the homes themselves. My initial idea is: 1 Use geothermal heat. 2 Use one industrial heat pump to supply 6 homes. 3 Use SIP panels, not brick. See the R value of brick - it is terrible. 4 Use underfloor heating. 5 Use a computer system to optimise all running parameters 6 Use solar tiles on the entire roof. We will also need an air conditioning system to prevent the build up of humidity. I think batteries are necessary as well to give the computer more options to plan the use of energy. They are so cheap now it is a bit of a no-brainer. We can gain a bit of an advantage by combining all six homes. It flattens out the usage rate so if one place is not using the solar in the summer another might be.
That sounds like a fun project!
It's not AC you want. It is heat recovery mechanical ventilation. It is something UK must finally start learning about as it is just sad when whole world is using it with way lover humidity but UK doesn't... And many houses are easy to adopt it.
I am going to install it in my bungalow along with capillary tube heating on the ceiling as well. Enough with radiators. Destroying the floor for underfloor heating would be too expensive, while I can simply roll out heating tubes on the loft between wood beams as my ceiling is made out of plasterboards now. Cover back with wool and call it a day... hopefully. Amazing stuff. Only exists about 50years on the continent....never seen in the UK I think...
@@havocchanel I think the way to do it with heat recovery of warm dirty air is to use a heat exchanger to take the heat from the exhaust air and dump it at the input of the heat pump which will be colder than the outside temperature hence giving greater heat transfer efficiency. A point about underfloor or even under ceiling radiators is you need efficient thermal contact with the room's air. If there is any insulation between the heating elements and the room air it will reduce the COP.
Hello, I am in the UK and have the exact same inverter as yourself, the inverter is one of the best purchases I have ever made and I have wired it up to exploit all of its many capabilities. Regarding batteries I would recommend looking at the Fogstar storage batteries, which I chose myself after extensive research into the subject - you can get a 15Kwh unit for a bit over £2000. You ideally want 2 of these for your specific setup, but it is almost trivial to expand should you only want one, they are compatible with the SunSynk inverter and have been running perfectly for over a year.
Which one is that? I can see the one for 3k but not 2k? (unless you mean DIY?)
It was £2k for the black friday sale. Back up to £2500 now.
Thanks!
@@tomt_techman search for 'Fogstar Energy 15.5Kwh 48V Battery' the price was £2200 last week or so (perhaps black friday promotion) but is now £2500; still an excellent deal in my opinion, they also have smaller 5Kwh for around £1050
@@UpsideDownFork Great price, I'll wait until the next discount day! I'm looking at 25-30kWh with a chunky Victron Multiplus inverter
We have a Give Energy 8.2kwh battery, with 4.5kwh of solar and have had these in place for two years. The panels I feel really come into their own with a battery, enabling a complete 24hr cycle of free solar generated energy at the best of times. At the worst of times, no solar generation but a battery which can run the house on cheap overnight electricity all day. Also with a battery, I can charge my EVwith good solar generation, then when the sun hides behind a cloud, the battery maintains the charge until the sun comes out again.
Great point 👍
Similar set up to me. We have the same inverter, but we have the 12kw Vaillant ASHP. We also have an EV and are on the Octopus Intelligent tariff. I've just added 2 X 15kwh grade a 314ah Seplos V4 kits from Fogstar which we charge off peak and they are excellent. So much so I've ordered a 3rd because even 30kwh (24kwh usable when discharging to 20%) doesn't quite cover our peak usage. Connects to the Sunsynk with no fuss and just works. Do it, you won't regret it!
We have 2 Seplos 16kWh DIY kit batteries from Fogstar, bought the second last week on offer for 1400 quid, and just setting it up now, game changer, potentially will get a third as we go into the spring, our system is 12.6kWp with an export agreement of 6.4kW, so we can generate loads of energy in the summer months, and would rather store it and export than let it go to waste (even with the 32kWh batteries)
Sounds good!
I found that if I took expected lifetime production and the installation cost and converted to pence per KWH both for the solar system and batteries it becomes a lot easier to reason about and model in the existing tariffs. For example on average a KWH from the solar costs about 7p snd storing in the battery 8p. So about 15p for a stored KWH, how does thst compare for evening and night time power costs. I found that a battery pays off in about 3 years if its used through the summar to move power as well, if its just for power shifting in the winter it takes three times as long.
That's interesting.
How about take down the NW pannel and set them up on the ground in the garden, or a S facing wall. I bet that would make a difference. Cost benifit of NW is pants.
My kids would find a way to smash them on the ground! 😁
If you think NW generation is bad, you'll be shocked at my next video which shows their generation over the course of the year!
@UpsideDownFork
Solar panels as goal posts. Hmmm.
Do not forget to take the savings from the equivalent car fuel and gas bills in the return of investment calculations.
Yep, very true 👍
We have 4 sunsynk 5.12kwh batteries which cover our usage for the day and makes us off grid for 7/8 months of the year
Nice! Green with envy! 😁
We have 7 south and 6 north facing 450w panels, 9.5kwh Givenergy battery and an EV on intelligent Octopus go.
3 bed semi 1920's on gas central heating ( heat pump coming Feb 25 ) 488kwh of power used at a cost of £38.59. Gas 555kwh at £35 for November. Charge battery and car at 7p night rate, battery covers house until 11:30pm when cheap rate starts.
👍 Nice! Are you considering doubling your battery capacity for next winter with the heat pump?
@UpsideDownFork Yes, I have been thinking about adding another because the pump would drain the 9.5 on a cloudy day quite quickly I would Imagine. Heat Geek have guaranteed us a cop of 3.6 @ 21C outside -2C. Alternatively, I may try and limit the output of the battery so it lasts the whole day and pay for the extra as I would not be paying the daily gas charge. I'm still generating almost 10kw on a sunny day here so Im hoping to only have a couple of expensive months.
For Batteries I’d go Powerwall 2 if you can. I’ve just bought an additional one for £5k installed as they are trying to sell off the old stock. I now have 27kwh of storage but the best bit is the in out power is 10kw so I never have to draw off the peak electric (some batteries are only 3.6kw in out and with your Heatpump on boiling the kettle will draw off the grid). The last octopus power hour (2 hours) I drew 36kwh of free electric into my car and the Powerwalls. On the turn down event I exported 9.9kwh in the hour which was worth £5.30 to me (£6 less the 70p it cost me to buy it). If all the Powerwall 2”s have gone get the 3 but I’ll bet the price will have gone back up.
Thanks! 😊
@ my friend has just had his export renewal off Octopus and it says it’s not a 12month fixed rate of 15p anymore and could go up or down. (Which means down🤣).
Had batteries and solar since 2019 but what is available has changed massively in the last couple of years. Do the batteries save money ? Our average cost per kwh is 12p over the 12 months, excluding fit payments. We generate 9mwh and use about 7mwh of that with the batteries in place HOWEVER the place the batteries make a difference is in the winter months, where you import at cheap rate. Sigenergy looks like an interesting idea given they have now integrated a 22kw dc rapid charger and also support 3 phase. If I was starting again and they were around, they would be on my shopping list ! In summary, our current setup means a 2k a year power bill instead of 6k. Even with a battery, you will still export a bit of power.
Thank you. I'm surprised how much has changed in the last 12 months since i've been looking!
Great info 👍
Glad you think so!
Your wife has a point. 🤔
In the future there might be the prospect of being charged for export, so a battery might be a necessity.
Yes, I agree 👍
I'm moving home (hopefully January) and looking to install the most panels I can - 28 - which will be 12.74kw. I wont have an EV, heat pump or battery to start with, but will most likely add these over time. Am I likely to export more than £1000 of electricity without having these? I read that if so it will be taxable. I would rather not have another complication to my tax return if possible.
You should speak to a tax adviser. Many people have been told that if you don't withdraw it from your energy company then you are not liable for any tax.
@@UpsideDownFork Thank you, that makes sense
I have a new installation of 18x solar panels (450 kw) with a 2x 5.2 kw battery... I'm only getting less than 0.5 kw per day. Is this normal? 8kw sunsynk 8kw 3 phase inverter..
There will be about 10-12 days every year with less than 1 kwh generation.
For how many back to back days do you have 0.5kwh ?
I got 4.5kWh today. Depending on lots of factors, you should be getting more than 0.5
Could you use the car for v2h?
Unfortunately not.
@UpsideDownFork that was our plan but the v2x tech seems to be taking a long time
@@neutron6220sadly.
Did you catch my video about it?
ruclips.net/video/hpxPaY_ghb8/видео.html
@@UpsideDownFork I didn't, thanks will give it watch 👍
I have one 16kWh battery, we charge it at 0.085p for a few hours off peak, and that, along with the solar is enough to power the house through the remainder of the day and night, I have just bought a second 16kWh battery as our system will generate so much energy in the summer that I want to store it to sell back, we dont import any electricity in any peak period. Batteries are a game changer, our 32kWh of battery storage has cost £3100 from Fogstar, they are the Seplos DIY kit, of course there is also a need to have MPPT's and a hybrid inverter (our batteries are on the DC side), I think AC batteries are a little different set up
Sounds good!
There are no AC batteries. That might be an all-in-one unit that includes an inverter? A bit like the tesla powerwall?
I love Victron energy products for battery storage if your looking for options. It gives you the flexibility to pick the batteries you want to use and expand the system over time.
I would also suggest that battery prices are plummeting so rapidly at the moment that they could well be half the price in a years time, it could still be worth waiting.
+1 for Victron Products
Thanks for commenting.
I'm looking to utilise my SunSynk 8.8kw hybrid inverter which is already in place and has high charge and discharge rates.
if keep waiting for better tech you will never have any