@@UpsideDownFork fuck the grid, that’s the governments job to make sure is operating properly. You main job is to extract as much cheap electricity as possible store it and run off of that. Yes that helps the grid at peak times but saving money and protecting from blackouts is the main priority. All the ‘green’ is intermittent so we need 100% generation capacity connected to the grid! I didn’t understand what the moronic politicians don’t understand about this?
@UpsideDownFork I have looked at the video as well after making the comment. And have realised that you are making the argument between having just solar or having just a battery. After just reading the title of your video I was thinking you are asking if you should now buy a battery as well as having solar, and I think you should. Sorry for the misunderstanding.
@@catalinomocea6986 I also agree with you. Battery allows for load shifting and thus saving money during winter season. During summer it helps with maximising solar export also. If there is scope to invest in extra solar or battery i would choose battery.
Of course greater savings can be made with a battery, but this ignores the installation cost. For this use case, a battery probably isn't worth it. If and when export rates drop significantly, or import rates go up like a couple of years ago, or battery install costs drop, the calculation will change.
Having extra panels was certainly my preference when I had my installation in 2021, but I still added a small battery (4.8kWh) at the same time, although the quotation suggested my payback period would be extended by a few months. However, the increase in electricity prices and the decrease in battery costs have meant that the payback period is now showing as much shorter than without the battery. Also, the battery makes 'playing the system' much simpler and profitable. Only about 20% of my energy comes from the grid rather than about 60% had I not had a battery.
@@UpsideDownFork My gut feeling is that installing North-West facing panels was a better option than spending this money on a large battery. However, I suspect an even better option would have been to add some battery storage. I've just added an additional 2.4kWh (£580) to my 6.2kWh solar panel system which probably extends the payback period slightly if I remain on my current Octopus tariff. However, I can do better if I switch to one of the Octopus smart tariffs that weren't available when my system was specified. For me it's not just about the money, it's also about reducing my carbon footprint. My imported electricity should drop to below 15% of my total usage and most of that will be when the grid energy supply is 'greenest'. Good luck with your experiment!
Spent an hour figuring out how to set my electric A+++ oven to cook during my E-On 00:00 - 00:07 EV charging period 👍(load shifting). It's taken many months to learn to cook 🤣[simple stuff] , but baked potatoes, lasagne, homity pie, roast veggies, flapjack, shortbread, pasties, apple crumble all look & taste right now (microwave reheat evenings, if needed). Two or three things can go in the same oven at the same time too, helps avoid processed food & plastic packaging and ... the kitchen smells fabulous at 7:00am in the morning 😊
I’m speccing that very same 8.8kw Sunsynk inverter for “project shed”. It’s very easy to add batteries to that inverter and there’s a wide range of makes that are compatible with it. The Dyness or Pylontech batteries are worth a look. Bimble solar have the Dyness 5kWh battery at around £800 right now. Another reason to add a battery: Backup power. You have the output terminal. Your entire house is electric (do you have a wood burner?). If not, consider your discomfort when the power goes out and add some backup power. It does change the payback considerations substantially when you have power, and no one else on the street does.
@@UpsideDownFork Those 14 years of uninterrupted supply are unlikely to be repeated -- seeing how the new Gov't is screwing the Elec Supply Industry and Planning. Expect incresing power cuts from now on. For me, this was the main consideration. Last winter, after a storm, over 100 postcode areas in Sonning and Twyford had 26 hours of power outage!!!!
Watched to the end. I then looked and saw I was not subscribed, when I thought I was! So I subscribed. I do enjoy your slightly edgy approach and questioning style and your boldness to challenge influencial people public statements on matters.
Like i said before, You need as many panels as you can on your property, Then buy a battery, after that make sure you get EPS installed for when we get blackouts
Got a battery, which from October to March when solar generation is poor, kicks in and makes sense so long as you have a cheap overnight tariff. I charge mine between 12.30 and 5.30, and it runs my house for the day. My Octopus usage graph literally only has usage for those hours. However, I had worked out 14kw would do in depths of winter, pre air source heat pump. I’d be keen to know how many kw a day an air source heat pump uses. I would extend my battery to accommodate as part of installation. In summer, you pretty much only spend on standing charges
@@UpsideDownFork thanks, 20kw of battery storage just for heat pump alone is quite an investment. Several weeks might be just an exception not worth trying to cover for. However, seems some serious spreadsheeting might be needed 🤦♂️on my part.
Thank you for sharing. You are definitely getting more succinct too! Our systems are diverging in readings, it seems on the S coast you got more average sun than we did in Oct! May I make a suggestion? On your slides, don't use the top left 10% of each slide so that your portrait doesn't obscure data and details. Particularly from 8:40-10:30 and 13:00-14:26. One point on optimisers. Your shading gradually covers all of your SW facing panels, so your optimisers only produce a benefit for a certain length of time during the transition from sun to shade. Our roof has a neighbour's roof peak shading that only covers 3-4 panels during the sun's arc. Without optimisers or a seperate string this would affect all 13 panels on that roof. The optimisers limit the shading to just the affected 3-4 panels. For us at least, the benefit from optimisers is much greater than in your case.
5-7pm cooking is one reason why a battery is helpful. Fogstar batts are very cheap and getting cheaper every month. Direct cell import plus a BMS is even cheaper. There is a cell glut at the moment so cell prices are particularly good. I've not had one for the first 14 years of PV, but have now decided they are cheap enough to make sense.
Batteries have all kinds of uses. It's been snowing here since Tuesday afternoon and the grid is out apparently a few blocks away. So I like having some backup power available. You do have a big battery in the drive, it would be nice if that was more integrated.
In the 1% club! Thanks to your videos my PW3 20 panel system gets installed this week. Thank you for all the content which prompted me to go this route!
Running our house on octopus go with a 8kwh storage battery. Over last 2 years averaged 11p per kw. Next project is solar on our Northeast facing roof. Great videos.
Good video keep them going, really usefull. Please finish the payback calculations, probably best done after 1 year to get a full gauge. I have had 25kw usable battery stoarge and an 8Kw Inverter installed for about a year now, and prevoisly had fitted in 2015 3800w inverter, 16x 240w panels all south facing 45 degrees pitch (3800 max perfect conditions), that paid for itself fairly quickly, estimated £1000 year saving (£600 generation pay and usage £400 saved on the electric bill) which was pretty much bang on. Once the batteries are payed off its more panels or upgrad the existing ones.
Subscribed 😊 Battery: YES I installed 14,85 kwp (facing south) with 18,4 kwh Battery. Since installation (end of July) we are self-sufficient. I need to say that we still have gas for the heating and hot water, heating pump ordered already. (Location Austria, near Vienna)
Just finishing install for our Vaillant 7kW ASHP on Wednesday and next Friday our electric will be upgraded to three phase. Like you I am going for solar only setup with seasonal offset, getting 44 panels installed with Enphase micro inverters and fingers crossed DNO approval for the full 16.7kW peak export.
I have 20 S facing panels. In the current weather I'm getting pretty much zero export. In detail, 45p worth of export (a little has topped up the battery) 1st-8th Nov inc. Even doubling the panels (impossible) would make no appreciable difference. OTOH i am still running at 95%+ off peak from a battery all filled at off peak (7p) prices. I dont know how big a battery youd need with a heat pump though. Mine is just average house use so a 9.5kWh battery is ample.
Watched till the end. Would love to just copy your setup - settings etc. going to get a British gas heat pump soon. First step in the journey. Liked and am subscribed.
My x5 NE / x5 SW /x3 NW bifacial Enphase IQ8HC system just commissioned 24 Oct. Will see how it goes through 2025 if a battery is or is not needed. They are all coming down in price so no rush.
Every month im impressed to see your system is beating expectations. Im looking forward to seeing what your system can do in November. Terrible start so far here
We’re on intelligent go and went battery first, this drops out average rate for the entire day to 8.1p per kWh and we use around 30 kWh a day. The solar panels are almost entirely export and didn’t really alter the payback period, but for our use didn’t really generate enough to offset not having the battery. Perhaps a different tariff would have worked out differently, but I like the certainty of Intelligent Go over the variable pricing of Agile. It’s more set and forget.
You've hit the nail on the head there. The battery + IOG gives more surety, whilst solar + Agile could be viewed as the gamblers route. Thanks for commenting.
I can't make more than a couple of kWhs a day with my solar array at the moment, and my usage was about 7kWh/day before the heat pump and that's using about 5kWhs/day at the moment too, so the battery is useful to me (upped my capacity when I put the heat pump in to qualify for a 0% mortgage to pay for both). Made a decent amount of money on Octopus saving sessions using the battery last winter too...
Watched the the end 😂 Not been into the weeds of my solar and batteries performances but I do know the batteries (11kw pylontech) make such a difference. On good sunny weeks we can turn off the cheap charging overnight and run on solar and battery. Problem is when you plug in the car to charge. If the home batteries aren't charging at the same time. The car drains the home batteries
Thanks for commenting and watching to the end. Your electrician can reconfigure your wiring, CT clamp position and inverter settings to avoid EV charging from home batteries in most cases.
I also wondered about getting some sort of smart Tariff, but we would also fall foul of the cooking time of 6pm. I also have a problem with getting a smart meter installed, the last suppliers engineer refused to do it and the DNO was supposed to come out and change our supply cables from the service fuse to the meter.
Good vid. Instinctively, now that you have the solar, a small battery installation would be productive throughout the year in supporting the non deferrable house load (cooking) and of course even better if it can hoover up negative priced power.😉
Great video it's a shame that heels are being dragged over VTH and VTG being an option. For example Renault are on the cutting edge by selling the new R5 (a relatively cheap EV) with VTG capability and most importantly a bi-directional Charger solution from their partner Mobilize, however even Octopus are still not able (or willing) to support VTG . In reality it should make no difference to the Octopus control/management Software whether the VTG is coming from a home battery or an EV as long as the right instructions are going to and from the API. In my opinion having a dual purpose Battery solution will be a game changer for adoption.
It's even more complex than that. Vehicle and charge point manufacturers have a standard to adhere to but there's still no agreement on parts of the protocol. Very frustrating as the technology and capability has been possible for years but it looks like we are still years away from widespread adoption.
I got a bargain battery from eBay in April and it’s a game changer. It’s only 6.5kwh but due to the bargain price, definitely worth while. If I was buying new, I would have at least 13 kWh and probably double that if funds allowed. The fact that you can charge the battery for around 8p per unit and export at 15p I think is the deciding factor. Obviously borrowing funds at a higher interest rate would not be wise. Look forward to following your journey over the next year. 👍 I would say also that buying to sell back seems a bit wrong but if it funds your battery, got to be good news.
Interesting figures re. your NW roof as i'm considering putting panels on mine also & looking forward to seeing your heat pump running costs through the winter . Liked & already subscribed 👍
Thank you for watching, commenting, liking and subscribing! Last year's heat pump data is here if you're interested ruclips.net/video/GM2MCaYyaHE/видео.html
Yes a home battery is well worth it. Using the Intelligent Octopus, with my Tesla Powerwall, I have been filling the battery overnight for 7p and now allowing as much solar to export at 15p. I am a high electric user, so for my home it is around 27kWh per day, then add ASHP and EV. My Panels were fitted in 2011 and extra 3.79kWh and Powerwall in 2020. I have found December and January are very similar and for those months I used 1327.5 Day units and 2244.6 Night units so 63% night use. November and February 722 Day and 1894 Night, so 72% night use. March and October 312 Day and 1930.1 so 86% night use. April to September 237.7 Day and 4715.7 Night, so 95% night use. Overall my avarage for the year is 80.58% night use. In the winter the battery can be out of energy in the afternoon. I was considering an extra battery but I am hoping V2G will arrive soon.
I got 15kwh of fogstar batteries, they are a life saver during these past few days due to the overcast and extreme high prices 0.60p+ pkwh , will be doubling my batteries it in the next few years, ( buying 3 server rack batties one by one)
From my brief/early experience of solar-&-battery, I would say, YES, battery.... I started in October with my PW3 installation and definitely battery capacity makes a load of sense. I charge in the 3-hr Flux window at night, and generally use minimal grid - definitely none in the high period. My roof is small, so I only have 11 panels - including NE roof. I'm thinking of getting the PW expansion battery when they become available early next year - so I will have 2x13.5 kWh storage. Payback time will likely be quite long, but I also have the security of running off grid.
Wanted to thank you for recommending Dorset Solar they did a 10k battery 5kw inverter and EV wallbox for us. We have only recently bought a Tesla and charging via Octopus intelligent go is incredibly cheap, after years of old banger ICE cars. We hope to get solar panels next year when we have our roof/s sorted. A fellow Southamptonian. 👍
I wrongly assumed you already had a battery - definitely get battery storage - aside from the cost benefit of export etc self consumption makes more sense rather than pushing electrons back and forth into the grid make the most them yourself 👍
Thanks for commenting! Conversion losses for home storage battery? Less losses if I'm feeding my neighbours homes. No point in self consuming power that I can sell for 15p when I can be consuming cheaper rate electricity instead? You see where my thoughts are headed...
@ but you acknowledge that you’re also having to import at peak times for cooking etc - that doesn’t make sense to me from the environmental perspective - I get that you are being paid (a lot) for export but depending on your battery size you will still do this once all your other loads are satisfied. As for losses - yes they are a small factor so you could say it’s better that someone else uses the electricity as is, instead but there is something satisfying about being “self sufficient” over much of the year (this November excluded!) My import went from 800kWh to 175kWh with a modest 4.8kWh pack - I still end up exporting in the summer even though I get paid deemed export on the FiT…
I have 10 x 400w panels linked to a 8.2 kWh battery and 3.6kW inverter. According to the Octopus app my 2024 import/export costs are £228 in credit. Sharing if of use to anyone but imho I'd say the battery is an essential addition to any solar set up. Im sure other opinions are available.
Meant to add, on my 5.5kW system I started with a 5kWh battery but quickly added a second. Same as you fully electric house, heat pump, ev, hob etc… think the sweet spot for our house is 18kWh of battery to get us reasonably through winter. So I was lucky and found someone selling another 5kWh less than 1 year old (all Puredrive) Got it for 1500quid vs 2.5k new. Now I’m at 15kWh, which realistically is 12ish useable. Overall makes a massive difference for the winter. Basically my plan is to never use peak pricing where I have to import.
In order to get the full 8kw out of your 8kw inverter when it's dark (no solar) you need batteries that can output 175A (so at least 2 of the newer sunsynk batteries (that can output 100A)
True. I never use more than 4kW unless the energy rates go negative so it's not currently a big consideration for me, but I did get the bigger inverter to future proof us against any potential future solution 🤞
Maybe the most cost-effective option would be to upgrade your EVSE to one that is compatible with Octopus Intelligent Go and enable “Dynamic Charging”. Then you will be able to access the lowest import rate, and carry on with running your import and export strategy as you have been doing. The cost of upgrading your EVSE equipment would be a fraction of buying say, 12-15 kWh battery capacity.
i would say include the standing charge if in credit for the year still don't do anything, if not add something either battery or more panels it is a bit of a 6 vs half dozen i would check the peak consumption then keep the peak vs off peak ratio in mind and and get cost on expanding the panels to meet that kwh figure and compare that cost to the cost of battery the panels will be active for more hours vs the battery would with only a 2hrs peak so i reckon the math would probably lean towards more panels ie if you use 4kwh in peak with an avg of 4 full sun hours avg you would need 1kwp array to produce that * that with lets say rule of thumb 1.45 peak vs off peak rates how does 1.45kwp panels installed cost compare to 5kwh battery naturally the ratio may change with roof orientation too if you have some brown outs from time to time the batery is a nice to have item how much is that worth
The start of November has been so dull here (Bournemouth) so I’ve been thankful of my battery, charged o/n at 7p/kWh which has just about covered daily usage for me (Giv AIO). It’ll be interesting to see your Nov numbers. Informative video watched till the end 😀
Watched to the end as always. A great informative update. I love having my Powerwall but would still like to add a North West facing array to supplement my South East array. Unfortunately higher management still says no!!!!!!! 😢😢
Know the feeling, trying to persuade her to let me have some bi-direction panels on a South facing wall ! Not going well so far. Low winter sun would be brilliant.
@@ians3328 Nice to know I am not alone in suffering Solar misery!!. A south facing wall, I would be interesting to see how it performs, good luck with management!!
Watched to the end. I've got solar too. I've had it for about 4/5 years now. Just switching my export and generation tariffs to octopus from good energy. Interested to see how I can make the most of the system. We are on the tracker not agile. Maybe we move to that once we get a good feeling of our generation and exporting. No heat pump here or battery storage. I do think about both. Not in a financial situation to do either upgrades. Very helpful video.
@@UpsideDownForkummmm... MG5, it's should have... Not sure of the electric specs but it's supposed it support v2l.... (Not being argumentative, you own one! Just what I've read)...
For me having a battery provides more opportunity to avoid peak electricity prices without having to time-shift consumption (my wife doesn't really cooperate with this anyway). I would have a bigger battery if I had more space in my garage. Using an EV as a battery extension would be interesting except that it just provides one more thing to manage if you also want to use it for travel. Solar has been dire in the last few weeks so charging a battery at night cheaply for use during the day/evening is more useful. This morning (10:56) my 7kW SE facing solar system is producing just 150W.
Got a 9.5kWh GivEnergy battery and a 180-litre Mixergy hot water cylinder (no solar diverter). When Agile is very cheap, I set the hot water cylinder to absorb 10kWh using the immersion element. What's your hot water setup like? A smart tank can be a cheap way to store excess grid electricity (or solar) as heat, for users who may not be able to install electrical batteries in their homes. The heat pump attachment would be more efficient, but I don't have compatible pipework (vented system).
Awesome. I have just installed my PW3 last September and now planning to install heat pump which will probably happen at some point next year. I am going to see first if 13.5kwh battery is going to be sufficient to run with the heat pump before making a decision to buy expansion pack. Out of curiosity, how much did the expansion pack cost you? Isl suspect it would be a little cheaper then the cost of a normal battery as there is no gateway?
@@ballathiam9486we have run a Pw since 2020, it’s made us mains free March to end of September. Now thinking about ASHP but realised we need another PW first. Just not enough solar in winter so extra storage is crucial to us going forwards.
@@lynnfisher4396just be aware that the Powerwall 2 is being discontinued and stocks are low , so if your thinking about it , get it sooner than later 👍
Be interesting to see how November looks. In the first 9 days I've generated 11kWh In these circumstances, the batteries are keeping me on 7p electricity
Stumbled across this video and enjoyed the info. I've just invested in 2 Powerwall 3 battery units and hope to save quite a lot of money through Octopus - I have some (11) solar panels on three different roofs ranging between se to sw. I was very interested in your panels facing more to the north as it may be worth me investing in some more, having seen your video! So, Thanks!
Welcome aboard! I've got a decent back catalogue about the NW facing aspect and those 16 panels. Check out the month of June to see the peak they managed.
I envy your coastal (Southern) location for solar, I noticed recently working in N Wales how often there was sunshine at the coast but cloudy inland. My NW location definitely suffering cloud cover by comparison. At least leaves are mostly gone from all the trees surrounding us, just need sunlight now!
You said you’re not avoiding the peak times for load so a battery is the only option to reduce that time slot cost. It is all about your cash vs running cost. So if you can afford a battery (or other kit) it’s just the time for payback of that investment. I’m just getting ready for a second battery to go in, oh and a water wheel generator but that one is a little bit further off but very worth it.
Thanks for commenting. I'm not focusing on the cost of a single time slot, a single day, week or even month. This is about what is the most cost effective over the course of a year. So far, solar panels are winning but we've yet to see how brutal winter can be.
In some ways I pulled the trigger too early. I got a EV, 18MWh/y system and, 30 TSLA in May. So I'll wait to get a battery now. I'm up. Powerwall 3 would be the go now for new installations.
A battery is a worthwhile investment. However, my solaredge battery has a 10 year warranty-but stopped working after exactly 7 days! Solaredge are supposed to be replacing it, but we've lost a whole months worth of charging at the night rate 😔 I actually wish we didn't get a battery and used the money to get extra panels!
I have installed solar and battery end of Sep and looking to install heat pump also with help of government grant. Sold two ice vehicles and bought two EVs. So far really happy with electricity bills. In the winter, the battery is really helping to load shift the usage. I charge the battery at night and use that energy from battery during the day, thus not using the expensive day tarrif. I think the battery will help you with lowering the cost, and maximising your export. I have power wall 3 and it's algorithm prioritises export during the day at 15p per kilowatt. It does a little top up charge from solar if it feels it won't last until 11:30 at night. I don't know how good the algorithm of other battery manufacturers but would recommend Pwerwall 3
Batteries are more use than panels. Three things needed to make best use. Panels, batteries and tariff that works for you. Batteries make so much sense.
I haven't got solar or batteries, but if I did get them, I'd definitely go for a battery system and get Tomato Energy 4.7p overnight rate and use this during the day. With cheaper and easier installation it's a no brainer for me. But you have already invested in solar, so I'd try to work out what you'd save if you can store excess solar energy instead of importing electric. You've got all the data, it's just a few hours on the spreadsheets! It will make you think more about weather prediction, car charging needs, etc. etc. though. Also check exporting energy at peak times to get more for your excess energy.
I've run the calculations on storing and using my own solar, that never stacks up. The flux model of exporting during peak periods also doesn't add up. At least not in my case. Thanks for commenting.
I’m so happy to be on eon next and also have a battery. We get 6.9p between midnight and 7am and also an export of 16.5p. Because of the battery we’ve used nothing but 6.9p, never used any expensive rates at all. The battery is a no brainer imo Also if you had been on eons tariff you would have made £35.29 instead of £32.08 Also with a battery the average import would be 6.9p or lower so would have been £36.65 instead of £67.87. Worth thinking about
Thanks for commenting. If I succeed in my strategy then my bill will be zero for the year. Importing at low cost is still paying a bill. Without a battery, Agile is still the most attractive tariff for most people unless they drive a lot of miles. Of course a battery changes the figures considerably.
I'm keeping a close eye on my ASHP usage as it slowly gets colder and colder.... It's so low though. Still not seeing any worth in battery at current prices but let's see what Dec & Jan looks like.
Very similar here, heat pump, two EVs, retired so home all day, average cost of imported power 7p as I am on intelligent go, with my two powerwalls (one was not big enough} we never use any daytime expensive energy! Bill so far this year minus £355 and no worries like last week when agile prices were enormous! Currently all solar is exported but not the batteries but I will be looking carefully at what Tesla offer next year when they start their new energy company. i used to be on the Tesla Energy Plan
@@UpsideDownFork indeed, but worth it, i grabbed the second in February with zero VAT and a good discount due to the V3 release that would not have been compatible with my V2.
Been enjoying your videos for some time, particularly because my main roof is NE facing. My question to you is, do you think the performance of a NE roof would be similar to your NW roof aspect? Very interested in your journey, induction hob coming to our house soon, and eventually a heat pump if it would work! Keep it up!
I subscribed...I thought i already had as watch most of your videos...I have 20kw of batterys but only 4.8kwp I also have the smaller 3.6kw version of your heatpump. It works hard heating an 1880's 3 bedroom 12 radiator setup in the very north west of Wales...but it still manages it with 0.5 heatcurve and max flow set to 35 degrees at the moment....I've had the heatpump for 19 months now. I'm still getting used to the fact the house is always the same temp! When I leave for work in the morning and it's frozen outside its a shocker as you always knew if it was freezing outside with an oil boiler by how much colder the house was before you got out of bed 😂
Heat pumps are amazing. I'm in my first winter and I'm getting used to the house always being warm. 1880's house and radiators - you'll get those heat-pump doubters annoyed. I'm getting space-heating COP over 6 at the moment with radiators only in a 1930s house.
Watched the end .. very interesting.. I install some pv systems ..but not under mcs .. installed some nw facing panels last year on my own house and thinking about fitting lots on the n facing main roof of my house .. ive yet to see any battery storage system that will pay back and make a significant profit over the projected life span of the system... and as for the mining of lithium to make them .. green they are not. Great info ..please crack on.!
@markturner503 Octopus wanted certification before our system could export. I wouldn't worry about the lithium extraction, the claims of non greenness tend to be overblown FUD
6 years in for me on a battery system. The load shifting really really helps and the battery will aid things. Some people might want to see cost per mile to show the usage on the mg5. We are finding that in winter the usage does go up due to the heat pump working harder. Octopus intelligence is best at the moment for us however I get the impression it might shift to being more accurate on how much the car is using during charging due to recent requests to re enable home chargers. Your figures on the north west performance are really interesting. I would look at a home battery solution but looks carefully as the systems available today have changed massively over the last 12 compared even to last year. High voltage batteries are more common with instead of parallel batteries running at a low DC voltage, series batteries running at a high voltage are being used and this means lower losses.
Good shout. Unfortunately I haven't recorded the mileage because it's my wife's car. I'll see if I can work out a routine to get that data because that really interests me, let alone catering for the masses. Is there really much of a % difference in losses between battery systems?
@@UpsideDownFork The system we have, lux inverter with pylontech battery is around 10% for the round trip losses even up to 15% depending on the time of year. Temperature is a big factor. Higher voltage batteries get lower losses generally.
With having a hybrid inverter already, putting a cheap battery on like a pylontech is a no brainer, especially with some of the agile prices recently. Just enough to last through the 3hr peak will probably be the most cost effective.
I would like to see your calculations on real cost per kwh of battery (electricity + amortized battery cost) quick calculation seem like battery degradation cost would be in the 5-10p kwh range. That said i agree with others here that helping the grid reduce peak load seems like a good idea.
Thanks very good....even if I don't agree with it all!. Always like you explanations. We are sitting up in the NE of Scotland and have just upped the batteries to 20kWh, and moved to Octopus Cosy. I found I couldn't afford the time to keep tracking on Agile of what I wanted to turn off and on at 4pm every afternoon. So went for the easy bit of just buying and using as much electricity as possible at 4-7 and 13-16. No heat pump yet, but can heat the house and water up by other means of electric power, as well as charge the battery, so it's good and easy, and cost hovers just above the 12.5p/kWh that Cosy charges for cheap rate times. Can only manage 12 solar panels on the roof due to the dormer windows (traditional Scottish house!) but do have half of those facing North East and can see how much sun they get, especially during the summer 6 months of the year. So agree with cover the roof! Look forward to the next one....cheers
The preliminary figures for a battery are not looking great, but it is only just starting to come into it's own this month as solar reduces and our household consumption really increases through heat pump use. Thanks for commenting.
Looking at Agile charts, it seems the average is 22.9p for Nov, and off peak 20.7p. Can you do a video explaining how you’re getting the electricity prices that you are?
Still thinking about a battery. Big modern all electric house with 5.6kw PV (85% consumed), heat pump and a low mileage EV (10k to 12k kWh a year). On agile for a few years, averaging 13p a kWh but still a price delta to exploit. I have a big model of how much I could save by time shifting imports from most expensive half hour to least expensive half hour, rate limited to 6kw of cheap import, and modelling for different battery capacities. If I could get a 13kwh battery for £7k (big if) then I get pay back in 6 years and over 10 years the IRR is 7% which is competitive with investments just about. Still pondering - I slashed costs by changing heat pump settings to work more outside of high cost periods. Cooking is the target.
Sounds like you have the exact data to make the most informed decision. If your PV inverter is a hybrid then you will get 15kWh for £3-4k easily. Even cheaper if you go for something like that fogstar.
Interesting. I've been on agile since the start of October. I charge my battery over night, then top up again in the afternoon to ensure 100% before 4pm. This way I import nothing during 4-7pm. Sunsynk is not as smart as if like with agile pricing. I'll get home assistant to work on that when I get time but for now I manually set the schedule when the prices come out at 4pm. For October judging by the figures in the octopus app, I averaged 12p/kWh. Much better than the fixed 23p I was on before. Almost all of my usage is from battery this way. Load shifting washing etc when I can, but oven is a big culprit, without battery it can't be shifted. Still trying to reduce usage, currently insulating the loft. (one of the first videos of yours I saw I think)
Agile tariff in November has been terrible. My unit cost is around 28p at the moment. Hoping that we get cheaper rates otherwise I will have to revert to fix tariff
do you think current high solar export rates will continue (and do you expect your DNO to allow more export)? if so, then solar may be better and consider the grid as your battery - effectively net metering so building up credit for use later. ignore the car - solar is better for exporting; EV is better to charge off peak rates. Battery IMO best considered as a home usage arbitrage device. Potentially even ignore heat pump as during winter it can be disproportionate but rest of year it won’t use a lot so not effecient to size for that. So size for core household use (everything except EV and heating IMO)
1. I did expect solar to fall until 2 weeks ago when octopus surprisingly increased the export rates for several of their tariffs, most notable was on octopus Go which has a huge market share. Now maybe they are just doing that for winter, I don't know? But it has me second guessing myself! 2. I think you're bang on the money with that second conclusion!
Last time I got a quote it was £7k. Too much for us, but I'm going to start getting another bunch of quotes and see what the credit payments look like.
I’m interested to know how you’re running your 7kW valliant ashp as my cop values are nowhere near as good as yours. Full WC? Curve value? I have 4.8kWh array on SE facing roof in central Scotland, only got 3.6kWh inverter, but have 13kWh batteries. Also have 2 EVs and on Octopus Intelligent tariff. From May I decided to change the way I run my system; I used to check weather night before and try and judge how much to charge the batteries so I’d be running on cheap all day if the sun wasn’t shining. Then when I realised I was buying at 7p and exporting at 15p I started charging batteries to 100% every night during off peak, ensuring any car charging was complete before 5:30am so not to draw from the batteries. The house would then run off any solar and the batteries during the day, but generally most solar was being exported straight to the grid. Come 8pm once all the heavy kitchen load was finished, I was force exporting anything left in the batteries down to 20%, then come 11:30pm start charging the batteries again. It’s definitely been a winner for me moneywise.
Room temp mod. Inactive. Curve set to 0.6. System designed to 45 @ -2 degrees. Schedule mostly 19-21 degrees except totally off 4-7pm. DHW heated to 48 degrees. Except for very very cheap agile sessions when I whack the whole thing to full power!
I’m in the position now, considering solar, battery etc. We have a semi with South West and North aspects. Currently leaning to S & W solar and a battery. But having watched your videos for a long time I’m doubting it and considering all solar.
Batteries are getting a lot cheaper quickly so waiting for batteries has no downside. I have solar, battery, heat pump. I have very carefully analysed my system and its costs. I'd say max out solar first, then heat pump and then battery. If you care about CO2, then the heat pump is best, followed by solar and then batteries.
@@UpsideDownFork I’m not sure, even with terrible generation in Q4 of the experiment I think over the year it’ll balance out. The benefit with a battery really comes into its own when the generation is low and you can utilise time of use tariffs.
Reckon the ‘glorious’ November stats 😂 will prompt you pressing the battery button. Be interested to see how it works out, as wouldn’t it be drained to 0% every day in Autumn and Winter. Congrats on the car, excellent long term useage reviews on that from Cleevely EV
If your import rate is close to your export rate, then a battery will likely not pay for itself. However, it definitely "feels good" to rely on the grid as little as possible 😇
Tarifs are very different from Belgium. We pay 0.27euro/kwh (tax included) electricity import and get 0.03 for export. So battery is very logical choice if you have a big pv array.
I can’t really fit solar panels, limited roof space, facing the wrong direction, but I’m still wondering if a battery is viable to eliminate day time import ?
@@-TheSingularity- this was what I was faced with, hence the test. 16 panels on the NW roof was very much frowned upon. Battery systems are more of a known quantity and easy to calculate for once you understand your consumption. If you're with Octopus energy, you can easily download your smart meter data and enjoy some spreadsheet time 👍
Good channel. We’ve recently moved into a house and inherited solar’s on the roof. I don’t believe we have a battery system or can connect to the solar’s. To be honest, I don’t know what else I can do to get the very best out of them…. Any help would be great.
What I don't like about batteries is it's difficult to find out the efficiency of the charging systems at typical and worst case as opposed to best case. For me, that's critical information that I think a lot of people overlook. It's part of the reason I didn't go for batteries when I went solar. But I do have bidirectional charging through my EVSE as I think you already know, and I've plotted efficiency curves for the system. It's a Wallbox Quasar which isn't available new anymore and I can set it to export or import anywhere between 3A and around 15A (it caps at 3.6kW for export and around 3.4kW for import; the hardware is capable of 32A but I have a G99 restriction). If I run it in the most efficient way possible, I think I get a round trip efficiency of 81% based on my measurements. If I import at the highest rate and export at the lowest rate, kind of doing V2H if you will, I'm getting 60% round trip efficiency. That is worst case (assuming charging was at maximum rate) and it does quickly go up from there, but most of the time I'm not pulling much from the grid. That's still useful for Octopus Cosy, though, which I've just gone onto, but you can't just say you're getting 12.25p/kWh all day; if I'm discharging at 3A then I'm paying 20.4p/kWh for the round trip which is still good but has to be factored in. If I'm cooking and the discharge is say 10A during that period then I'm paying 15.3p/kWh for the round trip while the house load is being covered. I can do V2G and simulate V2H and S2V but some of those cases don't make a lot of sense when factoring in the efficiency rates at low current settings.
Thanks for sharing that again. A lot of people don't think about the losses but those who have measured all seem to get 10-20% which starts to become quite considerable when you consider the standby losses of running a hybrid inverter on top of that as well.
I'd get a battery. The more houses off the grid at peak time, the less gas is burnt at the peaker plants and less strain on the grid
Fair point! Thanks for commenting.
@@UpsideDownFork fuck the grid, that’s the governments job to make sure is operating properly. You main job is to extract as much cheap electricity as possible store it and run off of that. Yes that helps the grid at peak times but saving money and protecting from blackouts is the main priority.
All the ‘green’ is intermittent so we need 100% generation capacity connected to the grid! I didn’t understand what the moronic politicians don’t understand about this?
Short answer, even without watching the video, YES get a battery!!!
Thanks for commenting. Don't you want to see the data before coming to that conclusion?
@UpsideDownFork I have looked at the video as well after making the comment. And have realised that you are making the argument between having just solar or having just a battery. After just reading the title of your video I was thinking you are asking if you should now buy a battery as well as having solar, and I think you should. Sorry for the misunderstanding.
@@catalinomocea6986 I also agree with you. Battery allows for load shifting and thus saving money during winter season. During summer it helps with maximising solar export also. If there is scope to invest in extra solar or battery i would choose battery.
Of course greater savings can be made with a battery, but this ignores the installation cost. For this use case, a battery probably isn't worth it. If and when export rates drop significantly, or import rates go up like a couple of years ago, or battery install costs drop, the calculation will change.
@@UpsideDownFork to be fair, you simply said "check this again soon when we have more data".
Having extra panels was certainly my preference when I had my installation in 2021, but I still added a small battery (4.8kWh) at the same time, although the quotation suggested my payback period would be extended by a few months. However, the increase in electricity prices and the decrease in battery costs have meant that the payback period is now showing as much shorter than without the battery. Also, the battery makes 'playing the system' much simpler and profitable. Only about 20% of my energy comes from the grid rather than about 60% had I not had a battery.
Nice! Thanks for sharing.
@@UpsideDownFork My gut feeling is that installing North-West facing panels was a better option than spending this money on a large battery. However, I suspect an even better option would have been to add some battery storage. I've just added an additional 2.4kWh (£580) to my 6.2kWh solar panel system which probably extends the payback period slightly if I remain on my current Octopus tariff. However, I can do better if I switch to one of the Octopus smart tariffs that weren't available when my system was specified. For me it's not just about the money, it's also about reducing my carbon footprint. My imported electricity should drop to below 15% of my total usage and most of that will be when the grid energy supply is 'greenest'. Good luck with your experiment!
Spent an hour figuring out how to set my electric A+++ oven to cook during my E-On 00:00 - 00:07 EV charging period 👍(load shifting). It's taken many months to learn to cook 🤣[simple stuff] , but baked potatoes, lasagne, homity pie, roast veggies, flapjack, shortbread, pasties, apple crumble all look & taste right now (microwave reheat evenings, if needed). Two or three things can go in the same oven at the same time too, helps avoid processed food & plastic packaging and ... the kitchen smells fabulous at 7:00am in the morning 😊
Nice! I really should do more of this stuff!
I’m speccing that very same 8.8kw Sunsynk inverter for “project shed”. It’s very easy to add batteries to that inverter and there’s a wide range of makes that are compatible with it. The Dyness or Pylontech batteries are worth a look. Bimble solar have the Dyness 5kWh battery at around £800 right now.
Another reason to add a battery: Backup power. You have the output terminal. Your entire house is electric (do you have a wood burner?). If not, consider your discomfort when the power goes out and add some backup power. It does change the payback considerations substantially when you have power, and no one else on the street does.
Thanks for commenting.
Power back up isn't a consideration for us. Never had an outage in the 14 years we've lived in this area.
@@UpsideDownFork Those 14 years of uninterrupted supply are unlikely to be repeated -- seeing how the new Gov't is screwing the Elec Supply Industry and Planning. Expect incresing power cuts from now on. For me, this was the main consideration. Last winter, after a storm, over 100 postcode areas in Sonning and Twyford had 26 hours of power outage!!!!
Watched to the end. I then looked and saw I was not subscribed, when I thought I was! So I subscribed. I do enjoy your slightly edgy approach and questioning style and your boldness to challenge influencial people public statements on matters.
I appreciate that! 😊
Like i said before, You need as many panels as you can on your property, Then buy a battery, after that make sure you get EPS installed for when we get blackouts
Thanks for commenting.
Got a battery, which from October to March when solar generation is poor, kicks in and makes sense so long as you have a cheap overnight tariff. I charge mine between 12.30 and 5.30, and it runs my house for the day. My Octopus usage graph literally only has usage for those hours. However, I had worked out 14kw would do in depths of winter, pre air source heat pump. I’d be keen to know how many kw a day an air source heat pump uses. I would extend my battery to accommodate as part of installation. In summer, you pretty much only spend on standing charges
Do you have daily usage figures for gas? Convert the kWh used by .85 efficient gas boiler (at best) to 4x (say) efficient heat pump?
Worst days last winter were ~40kWh. We had several weeks where the HP alone used 20kWh+
@@UpsideDownFork thanks, 20kw of battery storage just for heat pump alone is quite an investment. Several weeks might be just an exception not worth trying to cover for. However, seems some serious spreadsheeting might be needed 🤦♂️on my part.
Thank you for sharing. You are definitely getting more succinct too! Our systems are diverging in readings, it seems on the S coast you got more average sun than we did in Oct!
May I make a suggestion? On your slides, don't use the top left 10% of each slide so that your portrait doesn't obscure data and details. Particularly from 8:40-10:30 and 13:00-14:26.
One point on optimisers. Your shading gradually covers all of your SW facing panels, so your optimisers only produce a benefit for a certain length of time during the transition from sun to shade.
Our roof has a neighbour's roof peak shading that only covers 3-4 panels during the sun's arc. Without optimisers or a seperate string this would affect all 13 panels on that roof. The optimisers limit the shading to just the affected 3-4 panels. For us at least, the benefit from optimisers is much greater than in your case.
Thanks for commenting. I just need to reduce the size of my big head!
5-7pm cooking is one reason why a battery is helpful. Fogstar batts are very cheap and getting cheaper every month. Direct cell import plus a BMS is even cheaper. There is a cell glut at the moment so cell prices are particularly good. I've not had one for the first 14 years of PV, but have now decided they are cheap enough to make sense.
@@xxwookey thanks. I'll do my sums carefully. 👍
Batteries have all kinds of uses. It's been snowing here since Tuesday afternoon and the grid is out apparently a few blocks away. So I like having some backup power available. You do have a big battery in the drive, it would be nice if that was more integrated.
Thanks for commenting!
Good to see your decisions are based on facts / real data. Looking forward to hearing your conclusions from your year long exercise.
Amen! Data driven decisions are key here but some others do seem to be driven by an emotive argument.
Thanks for commenting.
Listened to the end ~ was walking along the Norfolk coastal footpath. But still followed along quite well.
Thanks for commenting and listening to the end!
Coastal footpath is exactly what I need right now!
In the 1% club!
Thanks to your videos my PW3 20 panel system gets installed this week. Thank you for all the content which prompted me to go this route!
Fantastic!
Even run the washer twice a wk , I live in wales 😊😊
👍
Running our house on octopus go with a 8kwh storage battery. Over last 2 years averaged 11p per kw. Next project is solar on our Northeast facing roof. Great videos.
Nice! Thanks for commenting.
Yes get a battery for sure, no brainer, 9.2kw, Givenergy might be a good option at the moment
We'll see what the data says shortly!
Good video keep them going, really usefull. Please finish the payback calculations, probably best done after 1 year to get a full gauge. I have had 25kw usable battery stoarge and an 8Kw Inverter installed for about a year now, and prevoisly had fitted in 2015 3800w inverter, 16x 240w panels all south facing 45 degrees pitch (3800 max perfect conditions), that paid for itself fairly quickly, estimated £1000 year saving (£600 generation pay and usage £400 saved on the electric bill) which was pretty much bang on. Once the batteries are payed off its more panels or upgrad the existing ones.
Thanks for commenting!
Subscribed 😊 Battery: YES I installed 14,85 kwp (facing south) with 18,4 kwh Battery. Since installation (end of July) we are self-sufficient. I need to say that we still have gas for the heating and hot water, heating pump ordered already. (Location Austria, near Vienna)
Thanks for commenting from Vienna! I lived there for a year (Döbling) and loved it!
Just finishing install for our Vaillant 7kW ASHP on Wednesday and next Friday our electric will be upgraded to three phase. Like you I am going for solar only setup with seasonal offset, getting 44 panels installed with Enphase micro inverters and fingers crossed DNO approval for the full 16.7kW peak export.
People underestimate how the grid could be an infinite battery with no degradation or upfront battery cost with the right setup.
@@HaiderAlDelfi
Huge PV system
Where about in the UK are you based?
@ East Midlands
@@HaiderAlDelfiI wish there was more info available and regularly updated on this!
Thanks for commenting and good luck on your G99!
I have 20 S facing panels. In the current weather I'm getting pretty much zero export. In detail, 45p worth of export (a little has topped up the battery) 1st-8th Nov inc.
Even doubling the panels (impossible) would make no appreciable difference.
OTOH i am still running at 95%+ off peak from a battery all filled at off peak (7p) prices. I dont know how big a battery youd need with a heat pump though. Mine is just average house use so a 9.5kWh battery is ample.
Thanks for sharing
Watched till the end. Would love to just copy your setup - settings etc. going to get a British gas heat pump soon. First step in the journey.
Liked and am subscribed.
Thanks for commenting and watching to the end!
My x5 NE / x5 SW /x3 NW bifacial Enphase IQ8HC system just commissioned 24 Oct. Will see how it goes through 2025 if a battery is or is not needed. They are all coming down in price so no rush.
Nice! Agreed 👍
Every month im impressed to see your system is beating expectations. Im looking forward to seeing what your system can do in November. Terrible start so far here
Thanks for commenting! November also terrible here! 😔
Watched to the end,i will be installing some solar panels on the north and south facing garage roof soon.
Thanks for commenting and watching to the end!
Watched to the end: can’t beat a Saturday morning spreadsheet!
Thanks for commenting and watching to the end!
We’re on intelligent go and went battery first, this drops out average rate for the entire day to 8.1p per kWh and we use around 30 kWh a day.
The solar panels are almost entirely export and didn’t really alter the payback period, but for our use didn’t really generate enough to offset not having the battery.
Perhaps a different tariff would have worked out differently, but I like the certainty of Intelligent Go over the variable pricing of Agile. It’s more set and forget.
You've hit the nail on the head there. The battery + IOG gives more surety, whilst solar + Agile could be viewed as the gamblers route.
Thanks for commenting.
I can't make more than a couple of kWhs a day with my solar array at the moment, and my usage was about 7kWh/day before the heat pump and that's using about 5kWhs/day at the moment too, so the battery is useful to me (upped my capacity when I put the heat pump in to qualify for a 0% mortgage to pay for both). Made a decent amount of money on Octopus saving sessions using the battery last winter too...
We've got to take the year as a whole to draw a proper conclusion.
Thanks for commenting.
Watched the the end 😂
Not been into the weeds of my solar and batteries performances but I do know the batteries (11kw pylontech) make such a difference. On good sunny weeks we can turn off the cheap charging overnight and run on solar and battery.
Problem is when you plug in the car to charge. If the home batteries aren't charging at the same time. The car drains the home batteries
Thanks for commenting and watching to the end.
Your electrician can reconfigure your wiring, CT clamp position and inverter settings to avoid EV charging from home batteries in most cases.
A great series which has been very inspiring. I’m hoping to order my SE/NW system this month…
Nice! Thanks for commenting.
I also wondered about getting some sort of smart Tariff, but we would also fall foul of the cooking time of 6pm.
I also have a problem with getting a smart meter installed, the last suppliers engineer refused to do it and the DNO was supposed to come out and change our supply cables from the service fuse to the meter.
The mess around smart meters is ridiculous. Been ongoing for years and still not sorted.
Good vid. Instinctively, now that you have the solar, a small battery installation would be productive throughout the year in supporting the non deferrable house load (cooking) and of course even better if it can hoover up negative priced power.😉
Thanks for commenting!
Great video it's a shame that heels are being dragged over VTH and VTG being an option. For example Renault are on the cutting edge by selling the new R5 (a relatively cheap EV) with VTG capability and most importantly a bi-directional Charger solution from their partner Mobilize, however even Octopus are still not able (or willing) to support VTG . In reality it should make no difference to the Octopus control/management Software whether the VTG is coming from a home battery or an EV as long as the right instructions are going to and from the API. In my opinion having a dual purpose Battery solution will be a game changer for adoption.
Its the national grid capacity thats the issue not Octopus, Hence the reason G98s are easy and many G99s are turned down for larger systems
@mojonojo3 Vehicle to Home does not need to go to the grid, just operate like a home battery
@@andyballard1883 except you weren't talking about v2h you were talking about v2g
@mojonojo3 sorry if you read my comment again VTH is the first thing I mentioned
It's even more complex than that. Vehicle and charge point manufacturers have a standard to adhere to but there's still no agreement on parts of the protocol.
Very frustrating as the technology and capability has been possible for years but it looks like we are still years away from widespread adoption.
I got a bargain battery from eBay in April and it’s a game changer. It’s only 6.5kwh but due to the bargain price, definitely worth while. If I was buying new, I would have at least 13 kWh and probably double that if funds allowed. The fact that you can charge the battery for around 8p per unit and export at 15p I think is the deciding factor. Obviously borrowing funds at a higher interest rate would not be wise. Look forward to following your journey over the next year. 👍
I would say also that buying to sell back seems a bit wrong but if it funds your battery, got to be good news.
Thanks for commenting!
Interesting figures re. your NW roof as i'm considering putting panels on mine also & looking forward to seeing your heat pump running costs through the winter . Liked & already subscribed 👍
Thank you for watching, commenting, liking and subscribing!
Last year's heat pump data is here if you're interested
ruclips.net/video/GM2MCaYyaHE/видео.html
Watched to the end! Encouraging stuff.
Thanks for commenting and watching to the end!
Yes a home battery is well worth it. Using the Intelligent Octopus, with my Tesla Powerwall, I have been filling the battery overnight for 7p and now allowing as much solar to export at 15p. I am a high electric user, so for my home it is around 27kWh per day, then add ASHP and EV. My Panels were fitted in 2011 and extra 3.79kWh and Powerwall in 2020.
I have found December and January are very similar and for those months I used 1327.5 Day units and 2244.6 Night units so 63% night use.
November and February 722 Day and 1894 Night, so 72% night use.
March and October 312 Day and 1930.1 so 86% night use.
April to September 237.7 Day and 4715.7 Night, so 95% night use.
Overall my avarage for the year is 80.58% night use.
In the winter the battery can be out of energy in the afternoon. I was considering an extra battery but I am hoping V2G will arrive soon.
Thanks for sharing!
I got 15kwh of fogstar batteries, they are a life saver during these past few days due to the overcast and extreme high prices 0.60p+ pkwh , will be doubling my batteries it in the next few years, ( buying 3 server rack batties one by one)
Glad it's working for you.
From my brief/early experience of solar-&-battery, I would say, YES, battery....
I started in October with my PW3 installation and definitely battery capacity makes a load of sense. I charge in the 3-hr Flux window at night, and generally use minimal grid - definitely none in the high period. My roof is small, so I only have 11 panels - including NE roof.
I'm thinking of getting the PW expansion battery when they become available early next year - so I will have 2x13.5 kWh storage.
Payback time will likely be quite long, but I also have the security of running off grid.
Nice. Thanks for commenting!
Wanted to thank you for recommending Dorset Solar they did a 10k battery 5kw inverter and EV wallbox for us.
We have only recently bought a Tesla and charging via
Octopus intelligent go is incredibly cheap, after years of old banger ICE cars.
We hope to get solar panels next year when we have our roof/s sorted.
A fellow Southamptonian. 👍
Hi; does your setup permit v2g or v2h (or will it be able to do so once the suppliers/dno's enable/permit it)?
@stevejeffrey1 Great to hear! Thanks for commenting.
@jesflynn4048 V2G is still far away.
I wrongly assumed you already had a battery - definitely get battery storage - aside from the cost benefit of export etc self consumption makes more sense rather than pushing electrons back and forth into the grid make the most them yourself 👍
Thanks for commenting!
Conversion losses for home storage battery?
Less losses if I'm feeding my neighbours homes.
No point in self consuming power that I can sell for 15p when I can be consuming cheaper rate electricity instead?
You see where my thoughts are headed...
@ but you acknowledge that you’re also having to import at peak times for cooking etc - that doesn’t make sense to me from the environmental perspective - I get that you are being paid (a lot) for export but depending on your battery size you will still do this once all your other loads are satisfied. As for losses - yes they are a small factor so you could say it’s better that someone else uses the electricity as is, instead but there is something satisfying about being “self sufficient” over much of the year (this November excluded!) My import went from 800kWh to 175kWh with a modest 4.8kWh pack - I still end up exporting in the summer even though I get paid deemed export on the FiT…
I have 10 x 400w panels linked to a 8.2 kWh battery and 3.6kW inverter. According to the Octopus app my 2024 import/export costs are £228 in credit. Sharing if of use to anyone but imho I'd say the battery is an essential addition to any solar set up. Im sure other opinions are available.
Batteries can save money, but I suspect they won't make sense for him (like in the last video).
Thanks for commenting. Every home varies so each must make their own calculation.
Meant to add, on my 5.5kW system I started with a 5kWh battery but quickly added a second. Same as you fully electric house, heat pump, ev, hob etc… think the sweet spot for our house is 18kWh of battery to get us reasonably through winter. So I was lucky and found someone selling another 5kWh less than 1 year old (all Puredrive) Got it for 1500quid vs 2.5k new. Now I’m at 15kWh, which realistically is 12ish useable. Overall makes a massive difference for the winter. Basically my plan is to never use peak pricing where I have to import.
Nice!
Oh and in hindsight I would max every square inch with panels!
Excellent…keep them coming.
Thanks for commenting!
In order to get the full 8kw out of your 8kw inverter when it's dark (no solar) you need batteries that can output 175A (so at least 2 of the newer sunsynk batteries (that can output 100A)
True. I never use more than 4kW unless the energy rates go negative so it's not currently a big consideration for me, but I did get the bigger inverter to future proof us against any potential future solution 🤞
Keep up the good work
Thanks, will do!
Till the end - I think you should do it.
Thanks for commenting and watching to the end!
Watched to the end! Looking forward to your conclusion
Thanks for commenting and watching to the end!
Maybe the most cost-effective option would be to upgrade your EVSE to one that is compatible with Octopus Intelligent Go and enable “Dynamic Charging”. Then you will be able to access the lowest import rate, and carry on with running your import and export strategy as you have been doing.
The cost of upgrading your EVSE equipment would be a fraction of buying say, 12-15 kWh battery capacity.
That's a good thought.
Interesting. We have a nightmare roof, although your NW experience offers some hope. Battery probably first though.
Thanks for commenting! 😀
i would say include the standing charge if in credit for the year still don't do anything, if not add something either battery or more panels
it is a bit of a 6 vs half dozen
i would check the peak consumption then keep the peak vs off peak ratio in mind and and get cost on expanding the panels to meet that kwh figure and compare that cost to the cost of battery
the panels will be active for more hours vs the battery would with only a 2hrs peak
so i reckon the math would probably lean towards more panels
ie if you use 4kwh in peak
with an avg of 4 full sun hours avg you would need 1kwp array to produce that * that with lets say rule of thumb 1.45 peak vs off peak rates
how does 1.45kwp panels installed cost compare to 5kwh battery
naturally the ratio may change with roof orientation too
if you have some brown outs from time to time the batery is a nice to have item how much is that worth
Some good thoughts, thanks.
No power cuts here to worry about.
The start of November has been so dull here (Bournemouth) so I’ve been thankful of my battery, charged o/n at 7p/kWh which has just about covered daily usage for me (Giv AIO). It’ll be interesting to see your Nov numbers. Informative video watched till the end 😀
Thanks for commenting and watching to the end!
I'm hoping Nov/Dec won't skew the year's results too much!
Watched to the end as always. A great informative update. I love having my Powerwall but would still like to add a North West facing array to supplement my South East array. Unfortunately higher management still says no!!!!!!! 😢😢
Know the feeling, trying to persuade her to let me have some bi-direction panels on a South facing wall ! Not going well so far. Low winter sun would be brilliant.
Thanks for commenting and watching to the end!
@@ians3328 Nice to know I am not alone in suffering Solar misery!!. A south facing wall, I would be interesting to see how it performs, good luck with management!!
We always watch to the end 😉
Thanks for commenting and watching to the end!
("Always" makes it sound quite ominous.)
Watched to the end. I've got solar too. I've had it for about 4/5 years now. Just switching my export and generation tariffs to octopus from good energy. Interested to see how I can make the most of the system. We are on the tracker not agile. Maybe we move to that once we get a good feeling of our generation and exporting. No heat pump here or battery storage. I do think about both. Not in a financial situation to do either upgrades. Very helpful video.
Good luck! Thanks for commenting.
You have an electric car so, you have a 50kw battery. Use load to home. Charge car @ night, then use the car battery in the evening when cooking etc….
My car doesn't have V2L.
@@UpsideDownForkummmm... MG5, it's should have... Not sure of the electric specs but it's supposed it support v2l.... (Not being argumentative, you own one! Just what I've read)...
@LongDarkTeatimeOfTheSoul there's 4 different variations of the MG5. Mine doesn't support it, some others do. 👍
For me having a battery provides more opportunity to avoid peak electricity prices without having to time-shift consumption (my wife doesn't really cooperate with this anyway). I would have a bigger battery if I had more space in my garage. Using an EV as a battery extension would be interesting except that it just provides one more thing to manage if you also want to use it for travel. Solar has been dire in the last few weeks so charging a battery at night cheaply for use during the day/evening is more useful. This morning (10:56) my 7kW SE facing solar system is producing just 150W.
Very true! Thanks for commenting.
Got a 9.5kWh GivEnergy battery and a 180-litre Mixergy hot water cylinder (no solar diverter). When Agile is very cheap, I set the hot water cylinder to absorb 10kWh using the immersion element. What's your hot water setup like? A smart tank can be a cheap way to store excess grid electricity (or solar) as heat, for users who may not be able to install electrical batteries in their homes. The heat pump attachment would be more efficient, but I don't have compatible pipework (vented system).
New Vaillant unvented tank with the larger heat pump coil fitted. I also increase the store temp during very cheap and negative agile periods.
Only £150 on temu now 12v lifepo4 😊 I buy one every other month , got 6 now, nearly never use grid electric 😊😊😊
What BMS do you use?
Yes you should , yesterday I pre ordered Tesla dc expansion pack so I will have 27kw of storage 🏦👍👌
Awesome. I have just installed my PW3 last September and now planning to install heat pump which will probably happen at some point next year. I am going to see first if 13.5kwh battery is going to be sufficient to run with the heat pump before making a decision to buy expansion pack.
Out of curiosity, how much did the expansion pack cost you? Isl suspect it would be a little cheaper then the cost of a normal battery as there is no gateway?
@@ballathiam9486hi £5250 fitted worth every penny
@@ballathiam9486 hey it cost me £5200 all in fitted 👍
@@ballathiam9486we have run a Pw since 2020, it’s made us mains free March to end of September. Now thinking about ASHP but realised we need another PW first. Just not enough solar in winter so extra storage is crucial to us going forwards.
@@lynnfisher4396just be aware that the Powerwall 2 is being discontinued and stocks are low , so if your thinking about it , get it sooner than later 👍
Be interesting to see how November looks. In the first 9 days I've generated 11kWh
In these circumstances, the batteries are keeping me on 7p electricity
November is NOT looking good.
@UpsideDownFork 0.4kWh today 😆
Stumbled across this video and enjoyed the info. I've just invested in 2 Powerwall 3 battery units and hope to save quite a lot of money through Octopus - I have some (11) solar panels on three different roofs ranging between se to sw. I was very interested in your panels facing more to the north as it may be worth me investing in some more, having seen your video!
So, Thanks!
Welcome aboard! I've got a decent back catalogue about the NW facing aspect and those 16 panels.
Check out the month of June to see the peak they managed.
@@UpsideDownFork Thanks, I will!
I envy your coastal (Southern) location for solar, I noticed recently working in N Wales how often there was sunshine at the coast but cloudy inland. My NW location definitely suffering cloud cover by comparison. At least leaves are mostly gone from all the trees surrounding us, just need sunlight now!
Interesting thought. It appears that some areas in the north had more irradiance than we did in the south during October.
You said you’re not avoiding the peak times for load so a battery is the only option to reduce that time slot cost.
It is all about your cash vs running cost. So if you can afford a battery (or other kit) it’s just the time for payback of that investment.
I’m just getting ready for a second battery to go in, oh and a water wheel generator but that one is a little bit further off but very worth it.
Thanks for commenting.
I'm not focusing on the cost of a single time slot, a single day, week or even month. This is about what is the most cost effective over the course of a year.
So far, solar panels are winning but we've yet to see how brutal winter can be.
@ a long cold winter is the issue with heat pumps and electricity costs but we seem to have mild winters currently.
I used savings made with solar to expand my battery storage.
Nice! Thanks for commenting.
In some ways I pulled the trigger too early.
I got a EV, 18MWh/y system and, 30 TSLA in May.
So I'll wait to get a battery now. I'm up.
Powerwall 3 would be the go now for new installations.
A battery is a worthwhile investment. However, my solaredge battery has a 10 year warranty-but stopped working after exactly 7 days! Solaredge are supposed to be replacing it, but we've lost a whole months worth of charging at the night rate 😔
I actually wish we didn't get a battery and used the money to get extra panels!
Thanks for sharing!
I have installed solar and battery end of Sep and looking to install heat pump also with help of government grant. Sold two ice vehicles and bought two EVs. So far really happy with electricity bills. In the winter, the battery is really helping to load shift the usage. I charge the battery at night and use that energy from battery during the day, thus not using the expensive day tarrif. I think the battery will help you with lowering the cost, and maximising your export. I have power wall 3 and it's algorithm prioritises export during the day at 15p per kilowatt. It does a little top up charge from solar if it feels it won't last until 11:30 at night. I don't know how good the algorithm of other battery manufacturers but would recommend Pwerwall 3
Nice! Thanks for commenting.
Batteries are more use than panels. Three things needed to make best use. Panels, batteries and tariff that works for you. Batteries make so much sense.
Thanks for commenting!
I haven't got solar or batteries, but if I did get them, I'd definitely go for a battery system and get Tomato Energy 4.7p overnight rate and use this during the day.
With cheaper and easier installation it's a no brainer for me.
But you have already invested in solar, so I'd try to work out what you'd save if you can store excess solar energy instead of importing electric.
You've got all the data, it's just a few hours on the spreadsheets!
It will make you think more about weather prediction, car charging needs, etc. etc. though.
Also check exporting energy at peak times to get more for your excess energy.
I've run the calculations on storing and using my own solar, that never stacks up. The flux model of exporting during peak periods also doesn't add up.
At least not in my case.
Thanks for commenting.
Great post still interested in the performance of your northwest facing panels
Thanks for commenting!
Watched and now Subscribed... 😂
Oh and yes you need a Battery.
Thanks for commenting and subscribing!
I’m so happy to be on eon next and also have a battery. We get 6.9p between midnight and 7am and also an export of 16.5p. Because of the battery we’ve used nothing but 6.9p, never used any expensive rates at all. The battery is a no brainer imo
Also if you had been on eons tariff you would have made £35.29 instead of £32.08
Also with a battery the average import would be 6.9p or lower so would have been £36.65 instead of £67.87. Worth thinking about
Thanks for commenting.
If I succeed in my strategy then my bill will be zero for the year.
Importing at low cost is still paying a bill.
Without a battery, Agile is still the most attractive tariff for most people unless they drive a lot of miles.
Of course a battery changes the figures considerably.
I'm keeping a close eye on my ASHP usage as it slowly gets colder and colder.... It's so low though. Still not seeing any worth in battery at current prices but let's see what Dec & Jan looks like.
Sounds like we're in the same boat. Thanks for commenting.
Very similar here, heat pump, two EVs, retired so home all day, average cost of imported power 7p as I am on intelligent go, with my two powerwalls (one was not big enough} we never use any daytime expensive energy! Bill so far this year minus £355 and no worries like last week when agile prices were enormous! Currently all solar is exported but not the batteries but I will be looking carefully at what Tesla offer next year when they start their new energy company. i used to be on the Tesla Energy Plan
Thanks for sharing! 2 x power walls is a lot of invested capital!
@@UpsideDownFork indeed, but worth it, i grabbed the second in February with zero VAT and a good discount due to the V3 release that would not have been compatible with my V2.
Been enjoying your videos for some time, particularly because my main roof is NE facing.
My question to you is, do you think the performance of a NE roof would be similar to your NW roof aspect?
Very interested in your journey, induction hob coming to our house soon, and eventually a heat pump if it would work!
Keep it up!
Yes, broadly speaking a NE aspect should perform the same as a NW aspect, all other things being equal.
Great show and I'm thinking of getting a Fogstar Battery for my solar panel system what do you think on this?
@@johnbyrne7931 it looks like a great option! 👍
I subscribed...I thought i already had as watch most of your videos...I have 20kw of batterys but only 4.8kwp I also have the smaller 3.6kw version of your heatpump. It works hard heating an 1880's 3 bedroom 12 radiator setup in the very north west of Wales...but it still manages it with 0.5 heatcurve and max flow set to 35 degrees at the moment....I've had the heatpump for 19 months now. I'm still getting used to the fact the house is always the same temp! When I leave for work in the morning and it's frozen outside its a shocker as you always knew if it was freezing outside with an oil boiler by how much colder the house was before you got out of bed 😂
Heat pumps are amazing. I'm in my first winter and I'm getting used to the house always being warm. 1880's house and radiators - you'll get those heat-pump doubters annoyed. I'm getting space-heating COP over 6 at the moment with radiators only in a 1930s house.
Great to hear another heat pump experience that matches ours!
Thanks for commenting.
Watched the end .. very interesting.. I install some pv systems ..but not under mcs .. installed some nw facing panels last year on my own house and thinking about fitting lots on the n facing main roof of my house .. ive yet to see any battery storage system that will pay back and make a significant profit over the projected life span of the system... and as for the mining of lithium to make them .. green they are not.
Great info ..please crack on.!
@markturner503 Octopus wanted certification before our system could export.
I wouldn't worry about the lithium extraction, the claims of non greenness tend to be overblown FUD
@@Biggest-dh1vr 🤣
6 years in for me on a battery system. The load shifting really really helps and the battery will aid things. Some people might want to see cost per mile to show the usage on the mg5. We are finding that in winter the usage does go up due to the heat pump working harder. Octopus intelligence is best at the moment for us however I get the impression it might shift to being more accurate on how much the car is using during charging due to recent requests to re enable home chargers. Your figures on the north west performance are really interesting. I would look at a home battery solution but looks carefully as the systems available today have changed massively over the last 12 compared even to last year. High voltage batteries are more common with instead of parallel batteries running at a low DC voltage, series batteries running at a high voltage are being used and this means lower losses.
Good shout. Unfortunately I haven't recorded the mileage because it's my wife's car. I'll see if I can work out a routine to get that data because that really interests me, let alone catering for the masses.
Is there really much of a % difference in losses between battery systems?
@@UpsideDownFork The system we have, lux inverter with pylontech battery is around 10% for the round trip losses even up to 15% depending on the time of year. Temperature is a big factor. Higher voltage batteries get lower losses generally.
With having a hybrid inverter already, putting a cheap battery on like a pylontech is a no brainer, especially with some of the agile prices recently. Just enough to last through the 3hr peak will probably be the most cost effective.
We will see. Unless Nov/Dec throw a big curve ball, you may be surprised at the battery cost calculations i've made.
I would like to see your calculations on real cost per kwh of battery (electricity + amortized battery cost) quick calculation seem like battery degradation cost would be in the 5-10p kwh range. That said i agree with others here that helping the grid reduce peak load seems like a good idea.
Very true! Battery calculations so far aren't looking great but we'll see what Nov/Dec turns up.
Thanks very good....even if I don't agree with it all!. Always like you explanations. We are sitting up in the NE of Scotland and have just upped the batteries to 20kWh, and moved to Octopus Cosy. I found I couldn't afford the time to keep tracking on Agile of what I wanted to turn off and on at 4pm every afternoon. So went for the easy bit of just buying and using as much electricity as possible at 4-7 and 13-16. No heat pump yet, but can heat the house and water up by other means of electric power, as well as charge the battery, so it's good and easy, and cost hovers just above the 12.5p/kWh that Cosy charges for cheap rate times.
Can only manage 12 solar panels on the roof due to the dormer windows (traditional Scottish house!) but do have half of those facing North East and can see how much sun they get, especially during the summer 6 months of the year. So agree with cover the roof!
Look forward to the next one....cheers
Thanks for the comment! 🙂
I'm keen to know if the battery would have been worth it - more panels is worth it
The preliminary figures for a battery are not looking great, but it is only just starting to come into it's own this month as solar reduces and our household consumption really increases through heat pump use.
Thanks for commenting.
Good food for thought
Thanks for commenting!
Looking at Agile charts, it seems the average is 22.9p for Nov, and off peak 20.7p. Can you do a video explaining how you’re getting the electricity prices that you are?
@@trailblazer7108 this video is about my October consumption. November is so far looking a lot worse.
Still thinking about a battery.
Big modern all electric house with 5.6kw PV (85% consumed), heat pump and a low mileage EV (10k to 12k kWh a year). On agile for a few years, averaging 13p a kWh but still a price delta to exploit. I have a big model of how much I could save by time shifting imports from most expensive half hour to least expensive half hour, rate limited to 6kw of cheap import, and modelling for different battery capacities.
If I could get a 13kwh battery for £7k (big if) then I get pay back in 6 years and over 10 years the IRR is 7% which is competitive with investments just about. Still pondering - I slashed costs by changing heat pump settings to work more outside of high cost periods. Cooking is the target.
Sounds like you have the exact data to make the most informed decision.
If your PV inverter is a hybrid then you will get 15kWh for £3-4k easily. Even cheaper if you go for something like that fogstar.
@ Thank you and yes you are right - but lack of space inside means I need an IP65 battery, which raises the cost somewhat!
Interesting.
I've been on agile since the start of October.
I charge my battery over night, then top up again in the afternoon to ensure 100% before 4pm. This way I import nothing during 4-7pm.
Sunsynk is not as smart as if like with agile pricing. I'll get home assistant to work on that when I get time but for now I manually set the schedule when the prices come out at 4pm.
For October judging by the figures in the octopus app, I averaged 12p/kWh. Much better than the fixed 23p I was on before.
Almost all of my usage is from battery this way.
Load shifting washing etc when I can, but oven is a big culprit, without battery it can't be shifted.
Still trying to reduce usage, currently insulating the loft. (one of the first videos of yours I saw I think)
Nice. Thanks for sharing.
Agile tariff in November has been terrible. My unit cost is around 28p at the moment. Hoping that we get cheaper rates otherwise I will have to revert to fix tariff
Yep, i'm trying to look at the long term and not fixate on a bad day, week or even month. Hard to keep that perspective when we have peaks of 80p!
do you think current high solar export rates will continue (and do you expect your DNO to allow more export)? if so, then solar may be better and consider the grid as your battery - effectively net metering so building up credit for use later.
ignore the car - solar is better for exporting; EV is better to charge off peak rates. Battery IMO best considered as a home usage arbitrage device. Potentially even ignore heat pump as during winter it can be disproportionate but rest of year it won’t use a lot so not effecient to size for that. So size for core household use (everything except EV and heating IMO)
1. I did expect solar to fall until 2 weeks ago when octopus surprisingly increased the export rates for several of their tariffs, most notable was on octopus Go which has a huge market share. Now maybe they are just doing that for winter, I don't know? But it has me second guessing myself!
2. I think you're bang on the money with that second conclusion!
Just to let you know you can use any 48v battery you like with your inverter. Some cheap chinese ones worth looking into
Thanks for commenting. Already covered in a prior vid. Fogstar, Seplos etc...
How do you find the inverter? If I add NE panels will have to upgrade or get a second
It does what I need. Some have fancier software and apps, but this has better hardware specs that most.
Last time I got a quote it was £7k. Too much for us, but I'm going to start getting another bunch of quotes and see what the credit payments look like.
Always worth getting some quotes!
I’m interested to know how you’re running your 7kW valliant ashp as my cop values are nowhere near as good as yours. Full WC? Curve value?
I have 4.8kWh array on SE facing roof in central Scotland, only got 3.6kWh inverter, but have 13kWh batteries. Also have 2 EVs and on Octopus Intelligent tariff. From May I decided to change the way I run my system; I used to check weather night before and try and judge how much to charge the batteries so I’d be running on cheap all day if the sun wasn’t shining. Then when I realised I was buying at 7p and exporting at 15p I started charging batteries to 100% every night during off peak, ensuring any car charging was complete before 5:30am so not to draw from the batteries. The house would then run off any solar and the batteries during the day, but generally most solar was being exported straight to the grid. Come 8pm once all the heavy kitchen load was finished, I was force exporting anything left in the batteries down to 20%, then come 11:30pm start charging the batteries again. It’s definitely been a winner for me moneywise.
Room temp mod. Inactive.
Curve set to 0.6.
System designed to 45 @ -2 degrees.
Schedule mostly 19-21 degrees except totally off 4-7pm.
DHW heated to 48 degrees.
Except for very very cheap agile sessions when I whack the whole thing to full power!
You should go for it, what do you have to lose? Forget the payback period and look at it from a stored energy perspective.
What do I have to lose? £3000 or more...
I’m in the position now, considering solar, battery etc. We have a semi with South West and North aspects. Currently leaning to S & W solar and a battery. But having watched your videos for a long time I’m doubting it and considering all solar.
Batteries are getting a lot cheaper quickly so waiting for batteries has no downside. I have solar, battery, heat pump. I have very carefully analysed my system and its costs. I'd say max out solar first, then heat pump and then battery.
If you care about CO2, then the heat pump is best, followed by solar and then batteries.
We'll see what the full year of data shows us. A cold and dark November and December could really tip the balance!
Thanks for commenting.
@@UpsideDownFork I’m not sure, even with terrible generation in Q4 of the experiment I think over the year it’ll balance out. The benefit with a battery really comes into its own when the generation is low and you can utilise time of use tariffs.
Reckon the ‘glorious’ November stats 😂 will prompt you pressing the battery button. Be interested to see how it works out, as wouldn’t it be drained to 0% every day in Autumn and Winter. Congrats on the car, excellent long term useage reviews on that from Cleevely EV
We shall see. Thanks for commenting.
If your import rate is close to your export rate, then a battery will likely not pay for itself. However, it definitely "feels good" to rely on the grid as little as possible 😇
True, I agree!
Tarifs are very different from Belgium. We pay 0.27euro/kwh (tax included) electricity import and get 0.03 for export. So battery is very logical choice if you have a big pv array.
Thanks for commenting from Belgium!
I can’t really fit solar panels, limited roof space, facing the wrong direction, but I’m still wondering if a battery is viable to eliminate day time import ?
@@-TheSingularity- this was what I was faced with, hence the test.
16 panels on the NW roof was very much frowned upon.
Battery systems are more of a known quantity and easy to calculate for once you understand your consumption.
If you're with Octopus energy, you can easily download your smart meter data and enjoy some spreadsheet time 👍
Good channel.
We’ve recently moved into a house and inherited solar’s on the roof. I don’t believe we have a battery system or can connect to the solar’s.
To be honest, I don’t know what else I can do to get the very best out of them…. Any help would be great.
Have a look at your electricity meter for clues and also where any cables coming from the roof are going?
What make and model of inverter do you have? Start there because you may be able to work out how to connect in and get some information from it.
@@UpsideDownFork Cheers, I think it is a basic one Growatt 3600MTL-S can’t seem to do a lot with it at all.
What I don't like about batteries is it's difficult to find out the efficiency of the charging systems at typical and worst case as opposed to best case. For me, that's critical information that I think a lot of people overlook. It's part of the reason I didn't go for batteries when I went solar. But I do have bidirectional charging through my EVSE as I think you already know, and I've plotted efficiency curves for the system. It's a Wallbox Quasar which isn't available new anymore and I can set it to export or import anywhere between 3A and around 15A (it caps at 3.6kW for export and around 3.4kW for import; the hardware is capable of 32A but I have a G99 restriction). If I run it in the most efficient way possible, I think I get a round trip efficiency of 81% based on my measurements. If I import at the highest rate and export at the lowest rate, kind of doing V2H if you will, I'm getting 60% round trip efficiency. That is worst case (assuming charging was at maximum rate) and it does quickly go up from there, but most of the time I'm not pulling much from the grid. That's still useful for Octopus Cosy, though, which I've just gone onto, but you can't just say you're getting 12.25p/kWh all day; if I'm discharging at 3A then I'm paying 20.4p/kWh for the round trip which is still good but has to be factored in. If I'm cooking and the discharge is say 10A during that period then I'm paying 15.3p/kWh for the round trip while the house load is being covered.
I can do V2G and simulate V2H and S2V but some of those cases don't make a lot of sense when factoring in the efficiency rates at low current settings.
Thanks for sharing that again. A lot of people don't think about the losses but those who have measured all seem to get 10-20% which starts to become quite considerable when you consider the standby losses of running a hybrid inverter on top of that as well.