7.36pKw solar array 2X10Kwhs batteries 6Kw inverter East Cornwall. Generated 288.32Kwhs Exported 16.33Kwhs Imported 523.7Kwhs at 7.5 per unit. Highest day for generation 7/11/23 17.6Kwhs lowest 30/11/23 2.04Kwhs. Have an ASHP which have now had to import at the peak rate twice in the last week due to -4 degrees at night for two nights running rest of time is running on batteries and any solar production. We can bring the batteries to 100% on the four hour off peak period due to the inverter being 6Kw Total bill from Octopus £57.52.
Very nice. Yeah, we've been using more peak power than I'd like but with any luck next Winter we'll be able to use Intelligent Go and have more battery capacity to use instead of peak power (assuming my calculations show that it'll be worthwhile, which is to be determined, of course).
Hey Tim, interesting you have hit the same issue with using peak power as we did. We simply adjusted our SOC settings so that we stop using battery when our SOC got to about 60% and then start using battery again around 4pm where the peak starts. We have found this mitigates the need to use peak power, so we end up coming out of the peak period with little SOC but then consuming grid again when prices settle around 7-7:30pm. Enjoying your updates, keep up the good work! :)
I’m expecting the money I make from the Octopus energy saving sessions to cover my extra winter usage, we have PV & 10kwh batteries. It worked well for us last year and that was before we had the batteries
Yes, I was impressed by how much we made in the recent GivBack sessions (video incoming soon). That will certainly help offset some of the heating costs this Winter!
This is the power of Intelligent. Plug the car in and get cheap hours in the middle of the day for a double dip cheap rate. A second hand Ohme charger is likely to be worth it.
I also use intelligent octopus but it can drain your house battery if it kicks in during the day! Depends on how your charger/battery is wired. Also it doesn’t always work which can be a pain. I had three failed sessions in the last 8 weeks.
Lots of questions. 1. Are you getting involved in Octopus saving sessions? They now pay for export. 2. Have you tried "Preheating" your home? If you dial down the temperature before the 0:30 window (Like off at 10PM) and then have the electric heating heat the home during the window at a slightly higher temperature than normal to get it above temperature. In theory that will make the battery last longer. 3. Unless your car manufacture joins octopus inteligent, you'll be waiting a while as GIV don't really have integrations as a focus.
We've signed up to the GivBack scheme, which I'll be doing a video on shortly. We don't pre-heat the house overnight as I don't think it really helps, since it just cools down again before the morning. If we are able to get onto Intelligent Go it might be more worthwhile as the off-peak period ends closer to the morning. According to GivEnergy the charger is already compatible with Intelligent Go and it's now up to Octopus to get it integrated. I'm not expecting that to happen in time for us to make use of it this Winter but I'm certain it'll be ready for next Winter.
@@TimAndKatsGreenWalk That's not entirely true from Givenergy. What they mean by that is the API exists and can do the necessary controls. From my understanding, octopus havent started yet
I have basically copied you Tim but with 5 unit multi-split and I am on intelligent with battery of only 5.5kwh useable. Preheating the ground floor of my house on cheap rate doesn't work for me as between 530am and 7am the house had cooled down so much it was just increasing energy usage for little temperature benefit. Like someone else said the battery is nowhere near enough and is now empty by 9am. On a cold day like last Saturday (high temperature of -1c) I am using more than 30kWh to heat the house. On a day when it is 5-8C outside it is half that amount. My house is pretty well insulated with 50cm loft insulation and cavity wall insulation as well. Definitely cheaper to heat my house on gas when it is cold outside as peak rate elec is more than scop*gas rate per kWh. But, I feel like it is still the right thing to do - this isn't about saving money for me, it is about saving the environment.
@@adamdevine7375 that's very interesting, I've found much the same. We used more than 30 kWh per day when it got below zero too. We have a very similar level of insulation so it sounds like our situations are quite closely aligned. And I agree about the cost vs. doing the right thing, that's always been my opinion too.
Nice again Tim , your 133kWh east west setup compares to my south facing array at 186 kWh system up in Central Scotland 5.1kW peak with 6.5kWh battery. Just like you I now charge the battery overnight, which lasts most of the day, and on cloudy days I top it up mid afternoon (Agile tariff). I would rather have my battery almost full in the morning and sell at 15p to ensure I miss buying at peak time.
Will be interested to see how December has been for you, it’s been awful for us. Having been pretty much bang on the PVGIS projections until December which has tanked and been only 50% of predicted. Can’t work out if the weather has just been particularly bad, or if the roofline of neighbours houses have been impacting production now the sun is so low.
I would expect your A2A to be able to dehumidify, An reason you do not just use that system? You mentioned before it has cooling functionality so the units must have the water draining vents...
@@jamesdc1993 Mine is cool mode, with a low fan speed. The heat to make the heat exchanger cold is dumped outside, so overall you're better with a dedicated dehumidifier OR a heatpump tumble
As mentioned by others the "dry" mode does actually cool the house at the same time so not that helpful in the Winter. I did try it out when we first got the system but decided it was not the right way to go about dehumidifying and that dedicated dehumidifiers worked a lot better (as well as providing a small amount of extra heating at the same time).
I currently have four 8.2 kw givenergy batteries with three 3 kw inverters, I manage to import approximately 30kw in the four hour window as I am also on octopus go. I have run a Darin airsource heat pump for the last eight years and in addition I have a2a fitted this year.So far on the coldest day this year I used 44 kw with 14kw at peak I have a total average harvest of 5350 kw per year from two solar arrays. I would consider upping your battery storage with additional inverters. Interestingly enough even with three inverters I could only force discharge on flux during the summer at a little over 6kw so probably there’s a cap on what I am able to send back to the grid. Hope some of my ramblings are useful.
Adding an extra inverter as well as extra battery would certainly speed up the charge rate, but would also incur extra cost, so that's to be factored in when I do my end of Winter calculations. I suspect the simplest and cheapest solution would be to simply add an extra battery to the existing inverter, assuming I can get onto Intelligent Go next Winter, which would give enough time to fill all the batteries up even with just the one inverter. We shall see though!
Moving to Intelligent Octopus Go the moment you can will be a huge help to top up the battery during the cheap extra sessions on days when your car is at home .
I have the same fun with our ASHP, battery lasts nowhere as long into the day, due to our increased electricity use. However, Intelligent Octopus can provide cheap times outside of it's core 6 hours, if you ae charging your EV. Initially I found this emptying my Tesla Powerwall as it thought it was peak rate, thus leaving no spare battery capacity that day. I have solved this making a Home Assistant automation to move the Powerwall to off grid at 100%. This means my EV is filled from cheap rate electricity and the bonus is that my battery will also top up if needed.
You could always go with a second battery the givenergy all in one would be the obvious choice it can work side by side with the current givenergy one and would allow you to change with two inverters Talk to the Geek did a great video on it.
Well, technically it'd work with the AC inverter and we've got a hybrid, so I don't think that's doable for us just yet. When I spoke to GivEnergy about it they said that AIO plus hybrid inverters would never be officially supported either, so I'm not holding out much hope. I absolutely would love to add an AIO but in reality I think the easiest and most cost effective solution would be to add an additional battery to our existing hybrid inverter.
Nice report and stats. Thank you Tim. I am glad I am not the only one suffering with a ridiculously small solar generation currently. So far this December has been AWFUL!! (58kWh in the first 12 days=4.8kWh per DAY!!). Our November figure was 332kWh so we did slightly better than you. Roll on summer!!
Assuming anyone does have enough battery capacity, essentially the supplier cheap rate becomes your actual rate minus any efficiency losses etc. THEN because it is so cheap, it is in fact preferrable to use imported electricity over your own solar, plus without the additional capacity you cannot take advantage of these saving sessions... which at £4.00 (per kWh) pay back could be worth over 50kWh (per kWh saved) to buy back in the night... these are crazy times!
These Saving Sessions seem to be rubbish for people with batteries. Obviously the aim is to reduce your usage against a baseline but the baseline seems to be your normal usage. Which is understandable but a bit frustrating. Most of the sessions take place in a window between about 16:00 and 19:00. That's when my battery is running the house and my grid usage is practically zero. So with a baseline of zero it's pretty hard to improve on that! So I get pretty much zilch reward despite taking nothing from the grid during the peak times.
the reason National Grid do these sessions during 16:00 - 19:00 is that is peak load on the network and the time when the reduction in load is required and power costs more to buy from generators, it makes no sense for NG to do these during non-peak / cheaper time frames@@FlatToRentUK
As it happens I'm planning on doing a quick video about the recent GivBack session where I earned £32. Ironically, the fact that we'd been using peak power for the heating in the preceding days meant our baseline for the session was quite high, so in combination with force exporting the battery (which was charged up a little just beforehand) our energy "savings" were extremely high. Extra battery capacity might mean we'd use less peak power so the baseline might be lower, but actually the export was what really made the difference. As you say, crazy times.
@@FlatToRentUKI heard that if you export from your battery then they pay £4 per unit exported if you opt in. I tried it last week to see and emailed octopus for confirmation.
Just an idea, if you are looking at another battery also look at another inverter,if you have capacity on your consumer unit , that way you will be able to charge both batteries with in the 4hrs off peak time .
Indeed, that's something I'm considering, but that does add extra expense (and complexity), of course. Hopefully we'd be able to get onto Intelligent Go next Winter in any case (assuming it's still around by then) so the charge rate would be less of an issue. We shall see what the data shows in the Spring!
For me here in Adelaide South Australia, November is the last month of spring. Generated 1.07 mwh off the north facing 6.3 kw house system and 1.08 mwh from the east west 6.5 kw shed system for a total of 2.15 mwh. Have the summer months ahead of me to build up credit for the winter. Haven't had to pay a power bill for a few months now. Might get a small one in the winter.
@@TimAndKatsGreenWalk Australia is one of the best places in the world for solar and this time of year on a clear day, both of my systems generate about 40 kWh each.
I would consider getting ripple energy shares rather than more battery as I think it works out cheaper per installed kwh. Project 4 is coming up in the next few weeks so worth doing the calcs for it. I intend to get some to add to my solar,battery and EV.
I already have some Ripple shares, as it happens. The data I'm gathering now will make it clear one way or another whether getting any extra battery capacity would be worthwhile too.
Interesting Tim I have similar thoughts here whether it is worth paying for extra battery storage I have 9.5kw battery and it’s gone by 10.00am. Its our first winter on A to A. But also can’t get on intelligent because Nissan isn’t compatible very frustrating. Look forward to hearing your views at the end of the winter
I'm very interested to see the results too! I have a hypothesis about how it's going to turn out but I'm curious to see how close that turns out to be to the actual result.
Hi Tim, I'm surprised to hear you say your heat pump costs more than your gas boiler did when you are on peak electricity but I suppose if it's cold outside your COP will be lower than your SCOP seasonal average. You have to get to a COP of below about 3.5 to be more expensive than a 90% efficient gas boiler (Flexible Octopus tariffs). On my wet ASHP system with it's 15kWh battery I'm finding the battery running flat early evening with the meagre sun at the moment but it does keep the whole house at 23°C and I've only just started to use my summer PV surplus banked in the Octopus account. Interesting calculation to be had about extra battery capacity - do you add the capital cost to the whole system and recalculate % return p.a. and payback time for the whole system (in which case it's only slightly different) or a separate calculation for just the extra battery cost and its saving? I think the whole system because you could separate other components out and alone they might not seem worth it 😉
Well, you can consider the marginal savings by adding the extra capacity and compare that to the cost the of the extra capacity. That will tell you if you'd save overall or not by adding the extra. But for the payback period of the whole system you would add it all together for sure.
I had a simple formula. Before Solar I was using around 20kWh a day so I put in 20kW Battery knowing I would have 18 kW of usable battery. In the summer I use electric water heating which utilises excess Solar and most of the time in the winter the Solar makes at least 2kW to make good the shortfall though occasionally I run out of battery about 22.00hrs. I have swapped in our Condenser tumble dryer for a heat pump model which reduces from 2/3 kWh to 400Wh The penny has just dropped that if I leave the EV plugged in that helps battery SOC during Peak CHEAP Rates and if I over produce on the Solar Octopus pay me 15p. I wish being a Spurs fan was as simple😂 as
@@TimAndKatsGreenWalk I can see that. Recently I have romanced the stone with an air heat pump heating system and I think I might need another 10kW of battery which is OK as I have a stacking system, but it then questions if my 8.8kW Inverter will allow all the load through without running out of capacity and calling on Peak rate which is 5 times the cost of gas which cancels out any CoP. My boilers are still working OK so if I did get involved it would be at the end of the boiler life The other issue is the large variance of view as to the efficiency of air heat pump unlike Solar and Battery which is a no brainer
@@mikejoseph425We have a 6Kwh Mitsubishi Ecodan ASHP with 20Kwhs of SolarEdge batteries twice since the middle of October have we had to charge the batteries outside of the 4 hour off peak window. Our batteries get to 100% every night using a 6Kw inverter. So a days electricity costs under £2 per day.
Ah the boxed in conundrum. GE won’t support two inverters or AIO addition to expand charging capacity, you can only get to 6 hours off peek charging with Octopus so can’t fill vast battery reserves either way. Heat pump efficiency reduces in very cold snaps and house needs more energy to maintain comfort so kills what battery you have early in the day so lots of peek usage pushing up cost to 30p and cop down so you are paying double the gas price or so and not being very green. We have 2 x 9.5kwh GE batteries and both were exhausted by midday so we are using weather compensation gas boiler during winter months and keeping batteries for house electricity consumption. No route to expand batteries to the c.60kwh we would need to not use gas or Peek electric and it would be hugely expensive for just a few months of the year.
Yeah, there's no point having vast battery capacity that would only get used for a few days a year. I'm hoping the data I'm gathering will give a good reliable way to calculate the sweet spot for us.
I've been looking at expanding the A2A heatpumps to cover the majority of the house (currently about half of it), but for winter even with a 9.5kWh battery, it seems rare that I finish the day with any juice. I don't think the payback is there for a battery you only need for 3 months of the year. Obviously would be interesting to see your calculations
Rather than getting a new battery, why not top up the battery in the early afternoon at standard rate? Make sure not to need anything during the peak rate.
@@TimAndKatsGreenWalkjust seen this, my comment doesn't help you then. We're on agile, most of the time it's pretty reasonable rates outside peaks....
@@robertbrand5139 yup, just replied 😉. I've considered Agile but overall Go seems to be cheaper given our usage. There is a handy app that compares the total cost per month for both tariffs.
This is the conundrum isn’t it? Having to use off-peak power in the winter to get the rate cheap enough. Have you also thought about getting an additional inverter/battery combo? It’s all cost though at the end of the day. Irrespective you’re doing the right thing environmentally. I do also wonder whether perovskite solar panels and more energy dense/cheaper batteries will make this all much of a smaller problem in future. I had this crazy idea the other day of wanting to calculate the total battery capacity I’d need to be able to run entirely off solar all year 😊. Have you done any calculations like this? Hypothetically obviously due to the sheer cost of storage!
Indeed, it's about whether or not I can do it reasonably cost effectively or not. I'm quite happy for it to not necessarily pay for itself just so long as it's not unreasonably expensive to do so (with a suitably vague definition of unreasonable). On the coldest days we'd need the best part of 40 kWh (house plus heating) so in order to get that much battery capacity it would definitely fall in the "unreasonably expensive" category. An extra 5-10 kWh on top of our existing 14 ish might just be worth considering, however. The data will reveal all when I do that calculation in the Spring!
@@tom.jacobs well, not necessarily. It's cheaper, for sure, but if it's colder overnight it actually becomes less efficient due to the temperature difference being greater between inside and out. Hence charging the batteries during off-peak then using that to power the heat pump during the day (i.e. effectively using off-peak power during peak times). Although in the case of a heat pump hot water cylinder I'd probably run that during off-peak times anyway so that the battery could be used for heating the house during the day instead.
Thanks for sharing. Why can't you charge batteries in parallel in separate banks? With standard 100A domestic supply, you theoretically have over 90kw of storage in 4 hours
It'd need more inverters, basically. And that would incur extra cost, so it's a question of whether that would be worth doing over simply adding an extra battery to the existing inverter, which is the simplest and cheapest option.
Goodness me! You're not wrong, I'd love to have more solar panels. Sadly there is not much roof space left (although keep your eye open for an upcoming video that will tackle this subject ;))
Thanks for sharing Tim. Why can't you have 2 battery banks and 2 chargers and charge up to twice as much in the given time? If the supply is 100A, shouldn't this be the limit and max charging at 24kwh? I'm guessing the system bottleneck is the rate battery can be charged
Yes, the limit is the inverter charge rate, so a second inverter would help with this, although incurring additional expense and complexity, so that all needs to be accounted for too. It should become clearer in the Spring once all the data has been gathered.
As an alternative, could you "save" the and just drain it over the peak period by using daytime grid power? You'd need to do some modelling to establish when/how long to use the grid for the A2A prior to 4pm but I'm sure it's possible
@@TimAndKatsGreenWalk It’ll be interesting to see what you come up with. I’d buy another in a heartbeat but I think it’d just be to make me feel good for not hitting the grid. It’d be a marginal saving compared to the significant saving of the primary battery IMO.
@@MrKlawUK yes, that's the problem, the marginal savings reduce a lot with further capacity. I'm the same though, I'd love to get more battery so that we use less peak power, even if it means it's not worth it financially. As long as it's not too crazy we might just do it anyway (if the savings don't quite cover the cost, say)!
I am definitely waiting for v2h / v2g to get properly sorted out. A 60 kWh battery with wheels and seats would then be well worth buying. My current car use is a tank of diesel every couple of months unless we visit the family in Scotland or the south coast. Winter use is even less. So not easy to justify buying an ev. Now Octopus is getting into ev leasing I suspect it will become worth it it by mid 2024.
@@stevejudyrobinson1771 I think V2X will happen eventually but it feels like it's still some way off. I hope I'm wrong and it suddenly becomes common next year!
The question of additional battery capacity is a tricky one, especially if its dependent on the Octopus Intelligent Go tariff. We've found that because the Intelligent Go tariff often gives slots outside of the usual 6 hour window, there is often an opportunity to charge the battery for a second time each day, which reduces the need for additional battery capacity.
Yes, good point. Something to factor in, although I don't know how often that happens so that's a hard thing for me to include. Do you often get extra slots during the day?
@@TimAndKatsGreenWalk We've found we are given slots within 30 minutes of plugging in so far. Sometimes they are continuous for several hours, other times it's a mixture of shorter slots with breaks in-between. Today we were given 15.31 until 19.16.
Have you though about changing tariffs well energy suppliers. I’ve just joined eon next and I get 7 hours of off peak electric 12-7am for 9.5P I have all the heating set to come on to preheat the house before I have to start using my battery.
I'm hoping to get onto Octopus Intelligent Go at some point which is 6 hrs at 7 p/kWh, so I'm happy to stick with Octopus for now. Never say never though.
Well I am up for a project of this type... however: a, Is such a thing for residential even viable? b, Is it allowed? (Personally my neighbours would not care) c, How would such a system integrate with existing solar and batteries? There are more questions than this of course...
As it happens I have considered it and it will form part of the video I plan on doing regarding adding extra generation to our house, so keep a lookout for that one (probably some time in the New Year).
@@TimAndKatsGreenWalk That'd be much appreciated. I just did a quick look around for residential turbines but gave up quite quickly! I wondered about if they need their own inverter (seems so) and how easily you can then connect to your house and meter if you've already got solar. And then about the cost compared to the return. Also will the DNO impose any limits if you've already got microgeneration? My solar is 8.9KWp so what would they say if I added a turbine?
@@elslopez when I said mini I did mean mini , the wires would still go in to your system the same as a solar panel would do , it would be interesting let’s say a 400w mini turbine and a 400w solar panel which would generate over a course of day, week, month, year , and to see the charts of each in real time throughout this time , my gut feeling is the turbine over the year would generate much more than the solar, but as yet never heard or seen anyone doing a comparison, somewhat strange to think nobody’s has done this , are the solar manufacturers scared?
I’ve looked at extra battery capacity and the best I can do is about 4 years payback. I know I’ll never get enough battery capacity to run the ASHP as that can use 20kW on a normal winters day and 60, 70 on really cold days. These are big numbers but in the round I’m expecting to be roughly cost neutral over the whole year as we generate loads in the summer and the hot water is very cheap. Interesting looking at the monthly stats, your 900kW is not dissimilar to my 1200kW for November but by October usage was 350 vs your 600. Swings and roundabouts. One thought on increasing your overnight battery charge capacity; get a second inverter. Even with a single solar panel it all becomes vat free and you’ll double your charge and discharge rate
An extra inverter would add additional cost, so that'd have to be factored in too, but it's something I'm considering. All should become clear once all the data is in and the calculation is performed.
If your EV has V2L surely that could be charged in parallel with your GIV battery and then use part of that in the day for the A2A heating? When I finally look to get an EV it must have V2L for me to purchase
Interesting. Our A2A consumption (5 A2A units plus 2x dehumidifiers) was 374 kWh for November. Very close to yours. Where do you find that Givenergy report? I can't see the same data laid out that way on dashboard or legacy dashboard.
Am I missing something? I would have thought prioritizing battery usage would be more cost effective than even considering exporting back to the network.
I'm not exporting back to the grid (in the Winter), what gave you that impression? Or do you mean the bit in the Summer? To which I would reply Octopus Flux export rates.
I agree totally. Buy at 7.5p and discharge battery instead of buying at 31p and if you then have excess, sell it to Octopus at 15p. KISS 8000kWh p.a. 32p-8p=24p x 8000 = £1,900 p.a. Saving plus Solar
@@mikejoseph425 my reply was to the original post, rather than your reply. Although, how one utilises solar and battery entirely depends on the particular tariff, so in my case Octopus Flux during the Summer encourages force export of the batteries at peak times because the peak export rate is so much higher than the off-peak import rate.
No, unfortunately not. I'm having to guess, more or less, based on what our gas usage was a couple of years ago, vs. what our A2A heating used last year. And that estimate is very rough and ready due to a large number of assumptions that I couldn't measure directly, as well as different usage patterns for the two systems. I suspect it's actually a lot better than 3x but I'm playing it safe so as not to make the savings seem higher than they really are. So in reality I think the savings are actually slightly better than what I'm reporting. This is one of the downsides of the A2A system we got, it doesn't give you the daily COP like some A2W systems do, which is a shame.
Hi Tim, I’ve mused on additional battery storage too but have opted to wait for bidirectional charging/V2H. Doesn’t GivEnergy allow more than one daily charge yet? If not, surely that’s only a firmware update away. Rob
Yes, technically you can do this although it's hidden away in the web portal settings. I don't need to do multiple charges per day though as Octopus Go only has the one off-peak period.
@@robjones8950 at the time there were no settings for multiple charging times but those have since been added (or at least they appeared for a time, I haven't checked recently if they are still there). In either case I think Go/Intelligent Go still works better for us overall.
The off-peak rate for Cosy is not as good as for Go or Intelligent Go, so it turns out that it's not quite as good overall (I did a video about that very question last year some time although using simulated data rather than real data). The data I'm gathering now should reveal how much battery capacity is the "sweet spot" once I've got the full Winter's worth, so keep your eye out for that video in the Spring.
As it happens our bill would be higher if we were on Agile instead of Go. So far this Winter the Go off-peak period has been on average a fair bit cheaper than the cheap periods of Agile, so charging up our battery, heating the hot water and charging the EV can all be done during that cheap Go period and thus it's cheaper overall for us. I have an app that allows me to keep an eye on the Agile prices, just in case, but so far it's looked like Go was the right choice for us. Our average November unit rate was 11.4p/kWh and so far for Dec it's been 16.7p/kWh.
@@stefanhorn6780 last Winter we applied for Go before we had the EV and they let us. It seems they don't always check for regular Go, although you definitely need one for Intelligent Go (either the car or charger has to be compatible and they do a test charge before they let you sign up!).
Hi Tim, as my main expense is hot water (heating) I am considering a system which uses solar during the day in the winter to power a heat pump which would then use old fashion thermal energy battery (also known as a hot water tank) to store the energy for use later that night. Did you ever consider such a solution?
There is nowhere near enough solar in the Winter to run our heat pump so unfortunately that wouldn't work for us. We generate maybe 3 kWh on a good day in December and the heat pump takes 20 kWh per day, on average. So there'd be nothing left to heat hot water.
We had the A2A last Winter too so don't have gas data to compare it to. Although I did do a comparison against the gas usage for the previous Winter to get the conservative 3:1 ratio, although in reality it's hard to make a direct comparison because the usage pattern is very different (gas is much more cyclical, whereas A2A is more steady). In reality I think the 3:1 ratio is a bit too conservative, really, I suspect it's closer to 3.5 or 4:1, but I didn't want to overinflate the estimated savings. The one annoying thing about our A2A system is that it doesn't give you the actual COP value on each day like some A2W systems do.
Hi folks These saving sessions Ive a 5kw GivEnergy battery and on octopus agile and never draw from the grid between 4-7 always from the battery Do you need an Export tariff to gain from this Or can I just discharge the battery to the grid and get payment that way? Hope that makes sense
I think you need to be set up with an export tariff as the MPAN number is different to the import one, so you'd need both for them to be able to measure how much you export during a saving session too. If you sign up for an export tariff you will get the export MPAN set up at for you at that point. It's worth having an export tariff for the Summer in any case.
Why are you on Octopus Go and not Intelligent Go? As I (vaguely) understand it it's something to do with Intelligent needing Smart charging but I'm not sure of what exactly the conditions for this are. A friend was on Go (he has an Ohme charger (smart), a VW E-UP (smart) and a Kia E-Niro (not smart)) and he told me he couldn't move to Intelligent because the Kia wasn't smart. But then he requested it again with Octopus and mentioned it's now charger or car that needs to be smart so he's now switched across. So do you know the exact situation and what's stopping you switching? If indeed you only need a smart charger or a smart EV I did wonder about just installing a charger myself (I don't have an EV). Because it'd be great to get the cheaper night rate and I'll need a charger at some point in the future.
We don't have a compatible EV or charger right now, although there are plans to get the GivEnergy EV charger into the scheme at some point so I'm hoping that by next Winter we should be able to get Intelligent Go. The Ohme was the first charger to be compatible. You do actually need to make a test charge in order to sign up properly, so you wouldn't be able to sign up with just the charger and no EV. You also have to make at least one qualifying charge per month in order to stay on the tariff (I think, although I'm not sure exactly how many charges you need to do). If you don't do those regular qualifying charges they'll kick you off to another tariff.
7.36pKw solar array 2X10Kwhs batteries 6Kw inverter East Cornwall. Generated 288.32Kwhs Exported 16.33Kwhs Imported 523.7Kwhs at 7.5 per unit. Highest day for generation 7/11/23 17.6Kwhs lowest 30/11/23 2.04Kwhs.
Have an ASHP which have now had to import at the peak rate twice in the last week due to -4 degrees at night for two nights running rest of time is running on batteries and any solar production. We can bring the batteries to 100% on the four hour off peak period due to the inverter being 6Kw
Total bill from Octopus £57.52.
Very nice. Yeah, we've been using more peak power than I'd like but with any luck next Winter we'll be able to use Intelligent Go and have more battery capacity to use instead of peak power (assuming my calculations show that it'll be worthwhile, which is to be determined, of course).
Hey Tim, interesting you have hit the same issue with using peak power as we did. We simply adjusted our SOC settings so that we stop using battery when our SOC got to about 60% and then start using battery again around 4pm where the peak starts. We have found this mitigates the need to use peak power, so we end up coming out of the peak period with little SOC but then consuming grid again when prices settle around 7-7:30pm. Enjoying your updates, keep up the good work! :)
Octopus Go has one off-peak period, then is peak rate for the rest of the day, so that strategy wouldn't help us.
I’m expecting the money I make from the Octopus energy saving sessions to cover my extra winter usage, we have PV & 10kwh batteries. It worked well for us last year and that was before we had the batteries
Yes, I was impressed by how much we made in the recent GivBack sessions (video incoming soon). That will certainly help offset some of the heating costs this Winter!
This is the power of Intelligent. Plug the car in and get cheap hours in the middle of the day for a double dip cheap rate.
A second hand Ohme charger is likely to be worth it.
I also use intelligent octopus but it can drain your house battery if it kicks in during the day! Depends on how your charger/battery is wired. Also it doesn’t always work which can be a pain. I had three failed sessions in the last 8 weeks.
We've got the GivEnergy EV charger now which is due to get the Intelligent Go treatment at some point. Once it does we'll switch as soon as we can.
Lots of questions. 1. Are you getting involved in Octopus saving sessions? They now pay for export.
2. Have you tried "Preheating" your home? If you dial down the temperature before the 0:30 window (Like off at 10PM) and then have the electric heating heat the home during the window at a slightly higher temperature than normal to get it above temperature. In theory that will make the battery last longer.
3. Unless your car manufacture joins octopus inteligent, you'll be waiting a while as GIV don't really have integrations as a focus.
We've signed up to the GivBack scheme, which I'll be doing a video on shortly. We don't pre-heat the house overnight as I don't think it really helps, since it just cools down again before the morning. If we are able to get onto Intelligent Go it might be more worthwhile as the off-peak period ends closer to the morning. According to GivEnergy the charger is already compatible with Intelligent Go and it's now up to Octopus to get it integrated. I'm not expecting that to happen in time for us to make use of it this Winter but I'm certain it'll be ready for next Winter.
@@TimAndKatsGreenWalk That's not entirely true from Givenergy. What they mean by that is the API exists and can do the necessary controls. From my understanding, octopus havent started yet
@@danielwalls5150 yeah, that's what I mean. It's good to go it's now up to Octopus to get it integrated, not GivEnergy.
I have basically copied you Tim but with 5 unit multi-split and I am on intelligent with battery of only 5.5kwh useable. Preheating the ground floor of my house on cheap rate doesn't work for me as between 530am and 7am the house had cooled down so much it was just increasing energy usage for little temperature benefit. Like someone else said the battery is nowhere near enough and is now empty by 9am. On a cold day like last Saturday (high temperature of -1c) I am using more than 30kWh to heat the house. On a day when it is 5-8C outside it is half that amount. My house is pretty well insulated with 50cm loft insulation and cavity wall insulation as well. Definitely cheaper to heat my house on gas when it is cold outside as peak rate elec is more than scop*gas rate per kWh. But, I feel like it is still the right thing to do - this isn't about saving money for me, it is about saving the environment.
@@adamdevine7375 that's very interesting, I've found much the same. We used more than 30 kWh per day when it got below zero too. We have a very similar level of insulation so it sounds like our situations are quite closely aligned. And I agree about the cost vs. doing the right thing, that's always been my opinion too.
Nice again Tim , your 133kWh east west setup compares to my south facing array at 186 kWh system up in Central Scotland 5.1kW peak with 6.5kWh battery. Just like you I now charge the battery overnight, which lasts most of the day, and on cloudy days I top it up mid afternoon (Agile tariff). I would rather have my battery almost full in the morning and sell at 15p to ensure I miss buying at peak time.
Yeah, that makes a lot of sense.
Will be interested to see how December has been for you, it’s been awful for us. Having been pretty much bang on the PVGIS projections until December which has tanked and been only 50% of predicted. Can’t work out if the weather has just been particularly bad, or if the roofline of neighbours houses have been impacting production now the sun is so low.
Yup, it's been pretty dreadful.
I would expect your A2A to be able to dehumidify, An reason you do not just use that system? You mentioned before it has cooling functionality so the units must have the water draining vents...
My A2A system can't heat an dehumidify at the same time. The dehumidify mode seems to simply be cool mode but with a very low fan speed
@@jamesdc1993 Mine is cool mode, with a low fan speed. The heat to make the heat exchanger cold is dumped outside, so overall you're better with a dedicated dehumidifier OR a heatpump tumble
As mentioned by others the "dry" mode does actually cool the house at the same time so not that helpful in the Winter. I did try it out when we first got the system but decided it was not the right way to go about dehumidifying and that dedicated dehumidifiers worked a lot better (as well as providing a small amount of extra heating at the same time).
I currently have four 8.2 kw givenergy batteries with three 3 kw inverters, I manage to import approximately 30kw in the four hour window as I am also on octopus go. I have run a Darin airsource heat pump for the last eight years and in addition I have a2a fitted this year.So far on the coldest day this year I used 44 kw with 14kw at peak I have a total average harvest of 5350 kw per year from two solar arrays.
I would consider upping your battery storage with additional inverters.
Interestingly enough even with three inverters I could only force discharge on flux during the summer at a little over 6kw so probably there’s a cap on what I am able to send back to the grid.
Hope some of my ramblings are useful.
Up date I have an additional 8.2 kw on the third inverter and four batteries coupled with two 3kw inverters.
Adding an extra inverter as well as extra battery would certainly speed up the charge rate, but would also incur extra cost, so that's to be factored in when I do my end of Winter calculations. I suspect the simplest and cheapest solution would be to simply add an extra battery to the existing inverter, assuming I can get onto Intelligent Go next Winter, which would give enough time to fill all the batteries up even with just the one inverter. We shall see though!
Moving to Intelligent Octopus Go the moment you can will be a huge help to top up the battery during the cheap extra sessions on days when your car is at home .
Yes, indeed, that's the plan. Hopefully the GivEnergy EV charger will get added to the list of compatible chargers at some point.
I have the same fun with our ASHP, battery lasts nowhere as long into the day, due to our increased electricity use. However, Intelligent Octopus can provide cheap times outside of it's core 6 hours, if you ae charging your EV. Initially I found this emptying my Tesla Powerwall as it thought it was peak rate, thus leaving no spare battery capacity that day.
I have solved this making a Home Assistant automation to move the Powerwall to off grid at 100%. This means my EV is filled from cheap rate electricity and the bonus is that my battery will also top up if needed.
Yup, I'm hoping we can move to Intelligent Go at some point, although I'm not expecting that to happen this Winter. Hopefully next Winter though.
You could always go with a second battery the givenergy all in one would be the obvious choice it can work side by side with the current givenergy one and would allow you to change with two inverters Talk to the Geek did a great video on it.
Well, technically it'd work with the AC inverter and we've got a hybrid, so I don't think that's doable for us just yet. When I spoke to GivEnergy about it they said that AIO plus hybrid inverters would never be officially supported either, so I'm not holding out much hope. I absolutely would love to add an AIO but in reality I think the easiest and most cost effective solution would be to add an additional battery to our existing hybrid inverter.
Nice report and stats. Thank you Tim. I am glad I am not the only one suffering with a ridiculously small solar generation currently. So far this December has been AWFUL!! (58kWh in the first 12 days=4.8kWh per DAY!!). Our November figure was 332kWh so we did slightly better than you. Roll on summer!!
Yes, indeed, hardy worth even considering solar in December! I think I'm averaging about 3 kWh per day so far.
Well this makes me feel a bit better, I couldn’t work out if it was just us!
Assuming anyone does have enough battery capacity, essentially the supplier cheap rate becomes your actual rate minus any efficiency losses etc. THEN because it is so cheap, it is in fact preferrable to use imported electricity over your own solar, plus without the additional capacity you cannot take advantage of these saving sessions... which at £4.00 (per kWh) pay back could be worth over 50kWh (per kWh saved) to buy back in the night... these are crazy times!
These Saving Sessions seem to be rubbish for people with batteries. Obviously the aim is to reduce your usage against a baseline but the baseline seems to be your normal usage. Which is understandable but a bit frustrating. Most of the sessions take place in a window between about 16:00 and 19:00. That's when my battery is running the house and my grid usage is practically zero. So with a baseline of zero it's pretty hard to improve on that! So I get pretty much zilch reward despite taking nothing from the grid during the peak times.
the reason National Grid do these sessions during 16:00 - 19:00 is that is peak load on the network and the time when the reduction in load is required and power costs more to buy from generators, it makes no sense for NG to do these during non-peak / cheaper time frames@@FlatToRentUK
As it happens I'm planning on doing a quick video about the recent GivBack session where I earned £32. Ironically, the fact that we'd been using peak power for the heating in the preceding days meant our baseline for the session was quite high, so in combination with force exporting the battery (which was charged up a little just beforehand) our energy "savings" were extremely high. Extra battery capacity might mean we'd use less peak power so the baseline might be lower, but actually the export was what really made the difference. As you say, crazy times.
@FlatToRentUK keep an eye out for my upcoming video on this very subject ;)
@@FlatToRentUKI heard that if you export from your battery then they pay £4 per unit exported if you opt in. I tried it last week to see and emailed octopus for confirmation.
Just an idea, if you are looking at another battery also look at another inverter,if you have capacity on your consumer unit , that way you will be able to charge both batteries with in the 4hrs off peak time .
Indeed, that's something I'm considering, but that does add extra expense (and complexity), of course. Hopefully we'd be able to get onto Intelligent Go next Winter in any case (assuming it's still around by then) so the charge rate would be less of an issue. We shall see what the data shows in the Spring!
For me here in Adelaide South Australia, November is the last month of spring. Generated 1.07 mwh off the north facing 6.3 kw house system and 1.08 mwh from the east west 6.5 kw shed system for a total of 2.15 mwh.
Have the summer months ahead of me to build up credit for the winter. Haven't had to pay a power bill for a few months now. Might get a small one in the winter.
Still utterly amazed at how much you can generate. I'm lucky to be getting 3 kWh a day right now!
@@TimAndKatsGreenWalk Australia is one of the best places in the world for solar and this time of year on a clear day, both of my systems generate about 40 kWh each.
@@Ryanhothersall that's fabulous.
I would consider getting ripple energy shares rather than more battery as I think it works out cheaper per installed kwh. Project 4 is coming up in the next few weeks so worth doing the calcs for it. I intend to get some to add to my solar,battery and EV.
I already have some Ripple shares, as it happens. The data I'm gathering now will make it clear one way or another whether getting any extra battery capacity would be worthwhile too.
Interesting Tim I have similar thoughts here whether it is worth paying for extra battery storage I have 9.5kw battery and it’s gone by 10.00am. Its our first winter on A to A. But also can’t get on intelligent because Nissan isn’t compatible very frustrating. Look forward to hearing your views at the end of the winter
I'm very interested to see the results too! I have a hypothesis about how it's going to turn out but I'm curious to see how close that turns out to be to the actual result.
Hi Tim,
I'm surprised to hear you say your heat pump costs more than your gas boiler did when you are on peak electricity but I suppose if it's cold outside your COP will be lower than your SCOP seasonal average. You have to get to a COP of below about 3.5 to be more expensive than a 90% efficient gas boiler (Flexible Octopus tariffs).
On my wet ASHP system with it's 15kWh battery I'm finding the battery running flat early evening with the meagre sun at the moment but it does keep the whole house at 23°C and I've only just started to use my summer PV surplus banked in the Octopus account.
Interesting calculation to be had about extra battery capacity - do you add the capital cost to the whole system and recalculate % return p.a. and payback time for the whole system (in which case it's only slightly different) or a separate calculation for just the extra battery cost and its saving? I think the whole system because you could separate other components out and alone they might not seem worth it 😉
Well, you can consider the marginal savings by adding the extra capacity and compare that to the cost the of the extra capacity. That will tell you if you'd save overall or not by adding the extra. But for the payback period of the whole system you would add it all together for sure.
I had a simple formula. Before Solar I was using around 20kWh a day so I put in 20kW Battery knowing I would have 18 kW of usable battery. In the summer I use electric water heating which utilises excess Solar and most of the time in the winter the Solar makes at least 2kW to make good the shortfall though occasionally I run out of battery about 22.00hrs. I have swapped in our Condenser tumble dryer for a heat pump model which reduces from 2/3 kWh to 400Wh
The penny has just dropped that if I leave the EV plugged in that helps battery SOC during Peak CHEAP Rates and if I over produce on the Solar Octopus pay me 15p. I wish being a Spurs fan was as simple😂 as
It gets more complicated once you electrify your heating system though, unfortunately.
@@TimAndKatsGreenWalk I can see that. Recently I have romanced the stone with an air heat pump heating system and I think I might need another 10kW of battery which is OK as I have a stacking system, but it then questions if my 8.8kW Inverter will allow all the load through without running out of capacity and calling on Peak rate which is 5 times the cost of gas which cancels out any CoP. My boilers are still working OK so if I did get involved it would be at the end of the boiler life
The other issue is the large variance of view as to the efficiency of air heat pump unlike Solar and Battery which is a no brainer
@@mikejoseph425We have a 6Kwh Mitsubishi Ecodan ASHP with 20Kwhs of SolarEdge batteries twice since the middle of October have we had to charge the batteries outside of the 4 hour off peak window. Our batteries get to 100% every night using a 6Kw inverter. So a days electricity costs under £2 per day.
Ah the boxed in conundrum. GE won’t support two inverters or AIO addition to expand charging capacity, you can only get to 6 hours off peek charging with Octopus so can’t fill vast battery reserves either way. Heat pump efficiency reduces in very cold snaps and house needs more energy to maintain comfort so kills what battery you have early in the day so lots of peek usage pushing up cost to 30p and cop down so you are paying double the gas price or so and not being very green. We have 2 x 9.5kwh GE batteries and both were exhausted by midday so we are using weather compensation gas boiler during winter months and keeping batteries for house electricity consumption. No route to expand batteries to the c.60kwh we would need to not use gas or Peek electric and it would be hugely expensive for just a few months of the year.
Yeah, there's no point having vast battery capacity that would only get used for a few days a year. I'm hoping the data I'm gathering will give a good reliable way to calculate the sweet spot for us.
I've been looking at expanding the A2A heatpumps to cover the majority of the house (currently about half of it), but for winter even with a 9.5kWh battery, it seems rare that I finish the day with any juice. I don't think the payback is there for a battery you only need for 3 months of the year. Obviously would be interesting to see your calculations
Yes, indeed, I'm very interested to see what the data shows by the end of the Winter. I have my suspicions but we'll see if I'm right!
Rather than getting a new battery, why not top up the battery in the early afternoon at standard rate? Make sure not to need anything during the peak rate.
That's the same rate. Octopus Go has one off-peak rate period and then peak rate for the rest of the day.
@@TimAndKatsGreenWalkjust seen this, my comment doesn't help you then. We're on agile, most of the time it's pretty reasonable rates outside peaks....
@@robertbrand5139 yup, just replied 😉. I've considered Agile but overall Go seems to be cheaper given our usage. There is a handy app that compares the total cost per month for both tariffs.
@@TimAndKatsGreenWalk Ahh, sorry. Was thinking you were on Flux like us.
@@dougbamford ah, gotcha. Yeah, if we were on Flux that'd be a sensible thing to do for sure.
This is the conundrum isn’t it? Having to use off-peak power in the winter to get the rate cheap enough. Have you also thought about getting an additional inverter/battery combo? It’s all cost though at the end of the day. Irrespective you’re doing the right thing environmentally. I do also wonder whether perovskite solar panels and more energy dense/cheaper batteries will make this all much of a smaller problem in future.
I had this crazy idea the other day of wanting to calculate the total battery capacity I’d need to be able to run entirely off solar all year 😊. Have you done any calculations like this? Hypothetically obviously due to the sheer cost of storage!
Indeed, it's about whether or not I can do it reasonably cost effectively or not. I'm quite happy for it to not necessarily pay for itself just so long as it's not unreasonably expensive to do so (with a suitably vague definition of unreasonable). On the coldest days we'd need the best part of 40 kWh (house plus heating) so in order to get that much battery capacity it would definitely fall in the "unreasonably expensive" category. An extra 5-10 kWh on top of our existing 14 ish might just be worth considering, however. The data will reveal all when I do that calculation in the Spring!
If your going to get a heat pump hot water cylinder the battery is definitely the way to go.
I suspect we will end up getting both, but all will be revealed in the Spring!
Guessing heating during off-peak is more efficient?
@@tom.jacobs well, not necessarily. It's cheaper, for sure, but if it's colder overnight it actually becomes less efficient due to the temperature difference being greater between inside and out. Hence charging the batteries during off-peak then using that to power the heat pump during the day (i.e. effectively using off-peak power during peak times). Although in the case of a heat pump hot water cylinder I'd probably run that during off-peak times anyway so that the battery could be used for heating the house during the day instead.
Thanks for sharing. Why can't you charge batteries in parallel in separate banks? With standard 100A domestic supply, you theoretically have over 90kw of storage in 4 hours
It'd need more inverters, basically. And that would incur extra cost, so it's a question of whether that would be worth doing over simply adding an extra battery to the existing inverter, which is the simplest and cheapest option.
I think I made 120kWh in one day at the end of November. That’s with 32kWp. You need more solar panels.😅
Goodness me! You're not wrong, I'd love to have more solar panels. Sadly there is not much roof space left (although keep your eye open for an upcoming video that will tackle this subject ;))
I approve of the amount of solar you have 🤣
Thanks for sharing Tim. Why can't you have 2 battery banks and 2 chargers and charge up to twice as much in the given time?
If the supply is 100A, shouldn't this be the limit and max charging at 24kwh? I'm guessing the system bottleneck is the rate battery can be charged
Yes, the limit is the inverter charge rate, so a second inverter would help with this, although incurring additional expense and complexity, so that all needs to be accounted for too. It should become clearer in the Spring once all the data has been gathered.
As an alternative, could you "save" the and just drain it over the peak period by using daytime grid power? You'd need to do some modelling to establish when/how long to use the grid for the A2A prior to 4pm but I'm sure it's possible
Yes, exactly, that'd be an option for sure, if you knew ahead of time how much peak you'd likely need. But that's the tricky bit!
There is a good video that looks at whether an extra battery makes financial sense. Now, where was it….. ;P
But this time I will have real data, not simulated!
@@TimAndKatsGreenWalk It’ll be interesting to see what you come up with. I’d buy another in a heartbeat but I think it’d just be to make me feel good for not hitting the grid. It’d be a marginal saving compared to the significant saving of the primary battery IMO.
@@MrKlawUK yes, that's the problem, the marginal savings reduce a lot with further capacity. I'm the same though, I'd love to get more battery so that we use less peak power, even if it means it's not worth it financially. As long as it's not too crazy we might just do it anyway (if the savings don't quite cover the cost, say)!
I am definitely waiting for v2h / v2g to get properly sorted out. A 60 kWh battery with wheels and seats would then be well worth buying. My current car use is a tank of diesel every couple of months unless we visit the family in Scotland or the south coast. Winter use is even less. So not easy to justify buying an ev. Now Octopus is getting into ev leasing I suspect it will become worth it it by mid 2024.
@@stevejudyrobinson1771 I think V2X will happen eventually but it feels like it's still some way off. I hope I'm wrong and it suddenly becomes common next year!
The question of additional battery capacity is a tricky one, especially if its dependent on the Octopus Intelligent Go tariff. We've found that because the Intelligent Go tariff often gives slots outside of the usual 6 hour window, there is often an opportunity to charge the battery for a second time each day, which reduces the need for additional battery capacity.
Yes, good point. Something to factor in, although I don't know how often that happens so that's a hard thing for me to include. Do you often get extra slots during the day?
@@TimAndKatsGreenWalk We've found we are given slots within 30 minutes of plugging in so far. Sometimes they are continuous for several hours, other times it's a mixture of shorter slots with breaks in-between.
Today we were given 15.31 until 19.16.
@@notjustageek ah, so does that mean you only get them if you've plugged in your car? Or have I misinterpreted that?
That's correct. Slots can be offered at other times but you only get the off peak rates if a vehicle is charging at the time.
@@notjustageek ah, good to know, thanks!
Have you though about changing tariffs well energy suppliers. I’ve just joined eon next and I get 7 hours of off peak electric 12-7am for 9.5P I have all the heating set to come on to preheat the house before I have to start using my battery.
I'm hoping to get onto Octopus Intelligent Go at some point which is 6 hrs at 7 p/kWh, so I'm happy to stick with Octopus for now. Never say never though.
Have you ever thought about getting a mini wind turbine to generate what solar doesn’t generate in the winter months.
Well I am up for a project of this type... however:
a, Is such a thing for residential even viable?
b, Is it allowed? (Personally my neighbours would not care)
c, How would such a system integrate with existing solar and batteries?
There are more questions than this of course...
As it happens I have considered it and it will form part of the video I plan on doing regarding adding extra generation to our house, so keep a lookout for that one (probably some time in the New Year).
@@TimAndKatsGreenWalk That'd be much appreciated. I just did a quick look around for residential turbines but gave up quite quickly! I wondered about if they need their own inverter (seems so) and how easily you can then connect to your house and meter if you've already got solar. And then about the cost compared to the return. Also will the DNO impose any limits if you've already got microgeneration? My solar is 8.9KWp so what would they say if I added a turbine?
@@FlatToRentUKI have looked at this a few times and it is much cheaper and easier to get ripple energy shares so I ended up doing that
@@elslopez when I said mini I did mean mini , the wires would still go in to your system the same as a solar panel would do , it would be interesting let’s say a 400w mini turbine and a 400w solar panel which would generate over a course of day, week, month, year , and to see the charts of each in real time throughout this time , my gut feeling is the turbine over the year would generate much more than the solar, but as yet never heard or seen anyone doing a comparison, somewhat strange to think nobody’s has done this , are the solar manufacturers scared?
I’ve looked at extra battery capacity and the best I can do is about 4 years payback. I know I’ll never get enough battery capacity to run the ASHP as that can use 20kW on a normal winters day and 60, 70 on really cold days. These are big numbers but in the round I’m expecting to be roughly cost neutral over the whole year as we generate loads in the summer and the hot water is very cheap.
Interesting looking at the monthly stats, your 900kW is not dissimilar to my 1200kW for November but by October usage was 350 vs your 600. Swings and roundabouts.
One thought on increasing your overnight battery charge capacity; get a second inverter. Even with a single solar panel it all becomes vat free and you’ll double your charge and discharge rate
An extra inverter would add additional cost, so that'd have to be factored in too, but it's something I'm considering. All should become clear once all the data is in and the calculation is performed.
If your EV has V2L surely that could be charged in parallel with your GIV battery and then use part of that in the day for the A2A heating? When I finally look to get an EV it must have V2L for me to purchase
Yes, that would help for sure, although not many EVs have that functionality just yet. Hopefully it'll become more common over time.
Interesting. Our A2A consumption (5 A2A units plus 2x dehumidifiers) was 374 kWh for November. Very close to yours.
Where do you find that Givenergy report? I can't see the same data laid out that way on dashboard or legacy dashboard.
On the left hand menu you'll see it near the bottom somewhere.
Am I missing something? I would have thought prioritizing battery usage would be more cost effective than even considering exporting back to the network.
I'm not exporting back to the grid (in the Winter), what gave you that impression? Or do you mean the bit in the Summer? To which I would reply Octopus Flux export rates.
I agree totally. Buy at 7.5p and discharge battery instead of buying at 31p and if you then have excess, sell it to Octopus at 15p. KISS
8000kWh p.a. 32p-8p=24p x 8000 = £1,900 p.a. Saving plus Solar
@@TimAndKatsGreenWalk I meant summer
@@mikejoseph425 my reply was to the original post, rather than your reply. Although, how one utilises solar and battery entirely depends on the particular tariff, so in my case Octopus Flux during the Summer encourages force export of the batteries at peak times because the peak export rate is so much higher than the off-peak import rate.
Thanks Tim, do you think you might be able to use your data to estimate your COP for the A2A to test if your 3x is valid?
No, unfortunately not. I'm having to guess, more or less, based on what our gas usage was a couple of years ago, vs. what our A2A heating used last year. And that estimate is very rough and ready due to a large number of assumptions that I couldn't measure directly, as well as different usage patterns for the two systems. I suspect it's actually a lot better than 3x but I'm playing it safe so as not to make the savings seem higher than they really are. So in reality I think the savings are actually slightly better than what I'm reporting. This is one of the downsides of the A2A system we got, it doesn't give you the daily COP like some A2W systems do, which is a shame.
How do you manage to consume 400kwh during summer...I have a spa, a sauna and ac turning on if it goes up to 30 C. I consumed less than 200 kwh
EV and hot water. All the data is shown quite clearly. And don't judge other people's lifestyles, it's pretty rude.
Hi Tim, I’ve mused on additional battery storage too but have opted to wait for bidirectional charging/V2H. Doesn’t GivEnergy allow more than one daily charge yet? If not, surely that’s only a firmware update away. Rob
Yes, technically you can do this although it's hidden away in the web portal settings. I don't need to do multiple charges per day though as Octopus Go only has the one off-peak period.
@@TimAndKatsGreenWalk I thought you told me that was why you decided against the Cosy tariff
@@robjones8950 at the time there were no settings for multiple charging times but those have since been added (or at least they appeared for a time, I haven't checked recently if they are still there). In either case I think Go/Intelligent Go still works better for us overall.
Hi what about Cosy and maybe you should of got a second 9.5 kw battery instead of the 5 kw
The off-peak rate for Cosy is not as good as for Go or Intelligent Go, so it turns out that it's not quite as good overall (I did a video about that very question last year some time although using simulated data rather than real data). The data I'm gathering now should reveal how much battery capacity is the "sweet spot" once I've got the full Winter's worth, so keep your eye out for that video in the Spring.
@@TimAndKatsGreenWalk I’m looking forward to the data generated 185 kw last month
have you considered agile ? i don't have an ev, but do have 10kwh battery it saves me quite a bit compared to standard, my avg cost is around 17p kwh
As it happens our bill would be higher if we were on Agile instead of Go. So far this Winter the Go off-peak period has been on average a fair bit cheaper than the cheap periods of Agile, so charging up our battery, heating the hot water and charging the EV can all be done during that cheap Go period and thus it's cheaper overall for us. I have an app that allows me to keep an eye on the Agile prices, just in case, but so far it's looked like Go was the right choice for us. Our average November unit rate was 11.4p/kWh and so far for Dec it's been 16.7p/kWh.
@@TimAndKatsGreenWalk good to know, currently don't have an ev, so have to stick with agile
@@stefanhorn6780 last Winter we applied for Go before we had the EV and they let us. It seems they don't always check for regular Go, although you definitely need one for Intelligent Go (either the car or charger has to be compatible and they do a test charge before they let you sign up!).
Hi Tim, as my main expense is hot water (heating) I am considering a system which uses solar during the day in the winter to power a heat pump which would then use old fashion thermal energy battery (also known as a hot water tank) to store the energy for use later that night. Did you ever consider such a solution?
There is nowhere near enough solar in the Winter to run our heat pump so unfortunately that wouldn't work for us. We generate maybe 3 kWh on a good day in December and the heat pump takes 20 kWh per day, on average. So there'd be nothing left to heat hot water.
@@TimAndKatsGreenWalk hmmmmm - ashame as my main expenditure is heating during winter - like 70% of my annual costs
can you compare with 2022 gas heating kwh and estimated COP for A2A?
We had the A2A last Winter too so don't have gas data to compare it to. Although I did do a comparison against the gas usage for the previous Winter to get the conservative 3:1 ratio, although in reality it's hard to make a direct comparison because the usage pattern is very different (gas is much more cyclical, whereas A2A is more steady). In reality I think the 3:1 ratio is a bit too conservative, really, I suspect it's closer to 3.5 or 4:1, but I didn't want to overinflate the estimated savings. The one annoying thing about our A2A system is that it doesn't give you the actual COP value on each day like some A2W systems do.
Hi folks
These saving sessions
Ive a 5kw GivEnergy battery and on octopus agile and never draw from the grid between 4-7 always from the battery
Do you need an Export tariff to gain from this
Or can I just discharge the battery to the grid and get payment that way?
Hope that makes sense
I think you need to be set up with an export tariff as the MPAN number is different to the import one, so you'd need both for them to be able to measure how much you export during a saving session too. If you sign up for an export tariff you will get the export MPAN set up at for you at that point. It's worth having an export tariff for the Summer in any case.
That’s what I thought
Just in the process of getting the export sorted
Ta very much
@@itsmrfish1 no problem. Good luck with getting that sorted. It can take a little while.
Why are you on Octopus Go and not Intelligent Go? As I (vaguely) understand it it's something to do with Intelligent needing Smart charging but I'm not sure of what exactly the conditions for this are. A friend was on Go (he has an Ohme charger (smart), a VW E-UP (smart) and a Kia E-Niro (not smart)) and he told me he couldn't move to Intelligent because the Kia wasn't smart. But then he requested it again with Octopus and mentioned it's now charger or car that needs to be smart so he's now switched across. So do you know the exact situation and what's stopping you switching?
If indeed you only need a smart charger or a smart EV I did wonder about just installing a charger myself (I don't have an EV). Because it'd be great to get the cheaper night rate and I'll need a charger at some point in the future.
We don't have a compatible EV or charger right now, although there are plans to get the GivEnergy EV charger into the scheme at some point so I'm hoping that by next Winter we should be able to get Intelligent Go. The Ohme was the first charger to be compatible. You do actually need to make a test charge in order to sign up properly, so you wouldn't be able to sign up with just the charger and no EV. You also have to make at least one qualifying charge per month in order to stay on the tariff (I think, although I'm not sure exactly how many charges you need to do). If you don't do those regular qualifying charges they'll kick you off to another tariff.