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How many panels to generate 10kWh/year?
How many panels to generate 10kWh/year?
Based on my actual meter readings
16 Mar 2025: 23,971 kWh
4 Mar 2026: 33,942 kWh
That’s 9,971 kWh used over 353 days, which annualises to ≈ 10,310 kWh/year
12 Sep 2024 (18,881) → 4 Mar 2026 (33,942):
15,061 kWh over 538 days ≈ 10,218 kWh/year
Roughly how many panels required to generate that kind of power? All the installs I’m seeing on here are a lot less.
South East London
South east facing roof
Cheers
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21 Replies
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Model it yourself for your location, orientation and slope
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My 16 panels generate just over 4100 kWh. 4 south and 12 west facing
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Going to vary based on location, roof orientation, roof angle, etc. I generated 10,400kWh in 2025 with 6.63kW S on roof, 2.43kW E + 2.43kW W Viridian in-roof, all on Enphase microinverters. Tesla PW2 + Zappi EV charger. 11.2kW export limit. Located Ipswich, Suffolk.
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I’d say about 20 panels, and about 30kWh of battery storage; to balance all your usage off your production, you’ll need to be able to store the energy produc3d on sunny summer days, so you can use it on murky November evenings…
Assuming you have gas central heating?
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Can’t be totally accurate but my 16 panels generates 6 MWh annually, so scaling up roughly that’s 25. However, you’ll not use it all by any stretch. At best you might halve your daytime use so about 4 – 5 MWh reduction. The rest of your solar can be exported for about 12p but that won’t stay that high.
Quick note about batteries. As a high user, you might find them useful but only if you can access a really cheap EV night tariff. My advice is always to fit panels, run them for a year and see where you are. That way, if you want to go ahead, you’ll know what size is best. You’ll have to use all of its capacity in house as it is now less than economic to export any battery excess to the grid
Good luck
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Without doing complex maths, about 10kwp-11kwp of panels .
We have 9.175kwp of panels in Anglia with a south east south west split and got 9.2MWh last year but it was a good year .
I posted a link the other day to a ChatGPT ‘natural language’ calculator for this type of thing if it’s of interest
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10k kwh pa. About what I use.
I have 7.5 kw on the roof split east west.
3 kw on ground mount in garden. South facing, tilted 35 degrees, shaded completey for 2 months of the year.. 2 kw flat on top of conservatory. South facing. Works well all year round. 32kwh of betteries
This lot generates enough to keep my bills to a minimum and charge me EV for free occasionally.
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Get as many and as powerful as you can afford fitted subject to local grid allowing. Then any surplus during the summer months pays the standing charge and builds up a credit for the winter months. Also allows for when we have bad periods when the sun dn wind is very low like start of last year. Use this information you got as a minimum.
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We have 6.4kw split east west.
This was our generation for 2025 5.3mwh
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We have a 10kw system (26 panels) in the South West on South facing roof. We make 8Mw per year on average but 9.4Mw last year which was exceptional.
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You can get a battery sized for your usage and charge at overnight cheap rates to top it up if solar doesn’t completely fill it. Battery is good because it allows you to use the electricity when you choose instead of needing to do everything when it’s sunny
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25-ish depending on your roof orientation etc. but you’ll export most of it in the summer and buy a lot in the winter so while you’ll be net zero in terms of KWh there will still be a cost. Batteries will help you use cheaper tariffs in the winter.
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My 3.33kWp array has generated almost exactly 50MWh in 15 years. It’s on a SSW facing roof with extremely little shading. So I think that means I’d need 10kWp of panels to generate 10MWh per year on average.
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10kWp
11 panels SSE
14 panels WSW
2024 – 9528 kWh
2025 – 10861 kWh
In the summer you will over produce and in the winter under produce
Some days in winter you will generate zero
Pic shows Dec 24 to Dec 25
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I also use around 10,000 kWh per year.
I have 40 panels south facing and 10kw inverter and 23kwh of battery storage. (I only ever charge the batteries via solar, don’t bother with grid charging)
My electric bill is about – minus £1000 as I export excess which covers my winter use
and earn about a grand back each year. With octopus lowering the export rate it’ll probably be about £600 up at the end of the year but I’m happy I no longer have bills……
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1 panel is more than enough. After all, 10kWh is only 20h of full sun output for a 500W panel.
If you really meant 10MWh/year then the answer is “roughly 10kWp of panels, maybe more like 12kWp if you’re in Scotland”.
Obviously it varies by location and orientation but as a very rough guide 1kWp of panels pointing roughly south with no shading will produce 1MWh per year in the south of the UK, a little less in the north.
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Mmmm … you are asking the wrong question … around 32 panels will generate 10MWh … but, you use most of your power in winter and generate most of your power in summer, so its kinda irrelevant. If it helps … to generate “about enough” in November and February around 50 panels. december and january you wont quite have enough, but its close.
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Our 21 panels facing SSE with a 5.6kW inverter produce 8-8.25MWh per year. However that is obviously mostly in the spring to autumn and we only produce around 200kWh in the deep winter months. We export about 2/3 so our net electricity bill is negative including powering two EVs but we still have gas central heating.
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completely agree I have had mine 7 months and originally was going to fit more but that meant more scaffolding and bigger battery. Now with export payments on the down there’s not as much return in generating more in the summer only to export for less and in winter extra panels would help a bit but not much. Same with a bigger battery I can already run the house in winter from the battery so not a great return if I add more storage. Looking at countries with more mature solar markets they get very small export payments or in some cases you have to pay the electricity ccompany to export (Austria for example at certain times of day)
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You need to be aiming for way higher than your current usage as you’ll generate way more than you need in summer and a fraction of what you need in winter.
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