Do Solar Panels Work in Winter? What to Expect in the UK
Yes. Solar panels keep generating in winter, including on cold and cloudy days, but they produce much less than in summer because the days are short and the sun is low. Here's how much less, using government data, and how a battery helps.
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- Solar panels work in winter. They generate from daylight, not heat, so they keep producing on cold and cloudy days.
- Government data shows UK solar panels produced about a third as much in October to December as in April to June.
- Cold doesn't hurt. Panels are actually slightly more efficient when they're cold. Short days and a low sun are what reduce output.
- A battery and a time-of-use tariff help most in winter, when you can charge cheaply overnight.
Do Solar Panels Work in Winter?
Yes. Panels turn daylight into electricity, and there's daylight all year round. They produce more in bright sun but still work under cloud.
The Energy Saving Trust confirms that panels generate on cloudy days, just less than in strong sunshine (Energy Saving Trust, solar panels). What makes winter output lower is shorter days, a lower sun that reaches the panels at a shallower angle, and more cloud.
How Much Do They Produce in Winter?
The government measures what thousands of Feed-in Tariff solar systems actually generate. In 2024/25, output from October to December was about a third of output from April to June.
| Period | Load factor | Roughly per kWp | A 6.7 kWp system, per day on average |
|---|---|---|---|
| April to June 2024 | 13.6% | about 295 kWh | about 22 kWh |
| October to December 2024 | 4.7% | about 105 kWh | about 8 kWh |
| Whole year (median) | 9.2% | about 810 kWh | about 15 kWh |
Load factors from DESNZ, Feed-in Tariff load factor analysis 2024/25 (published 18 December 2025). "Load factor" is output as a share of what the system would make running at full power all the time. kWh figures are our conversion of those load factors. Many FiT systems are older, so a modern system will often do a little better. 6.7 kWp is the most common Spark system in 2026.
December and January are usually the lowest months, and output varies a lot from day to day. A bright, frosty day can produce far more than a dull one. Your quote includes a month-by-month forecast for your roof.
Cold, Snow and Short Days
It's the light, not the temperature, that matters.
- Cold helps slightly. Panels lose a little output as they heat up. The Aiko panels we fit lose 0.26% for each degree above 25°C, so on a cold, bright day they run slightly more efficiently than in a heatwave.
- Snow blocks light while it sits on the panels, but it usually slides off dark, angled glass quickly once the sun reaches it. Don't climb onto the roof to clear it.
- A low sun means steeper roofs catch winter light better, and nearby trees or buildings cast longer shadows. We check winter shading at your survey.
Making the Most of Winter
In winter, your panels cover less of your use, so the way you buy the rest matters more.
- Use a battery overnight. On a time-of-use tariff, a battery can charge at the cheap overnight rate and run your home through the evening peak. See our guide to tariffs for battery owners.
- Use power in daylight. Run the washing machine or dishwasher in the middle of the day, when the panels are producing most.
- Judge it over a year. Summer surplus makes up for winter. Our payback guide uses a full year's generation.
Your Questions, Answered.
Do solar panels work in winter in the UK?
Yes. They generate from daylight, so they keep working in winter and on cloudy days, but they produce much less than in summer because days are shorter and the sun is lower.
How much do solar panels produce in winter?
Government data for 2024/25 shows UK solar systems produced about a third as much from October to December as from April to June. For a 6.7 kWp system that is roughly 8 kWh a day on average in late autumn and winter, against about 22 kWh in spring and early summer.
Do solar panels work when it's cold?
Yes, slightly better than when it's hot. Panels lose a little efficiency as they warm up, so cold, bright days are good for solar.
Do solar panels work in snow?
Not while snow covers them, but snow usually slides off angled panels quickly once the sun reaches them. Don't climb onto the roof to clear it.
Is a battery useful in winter?
Yes. With a time-of-use tariff, a battery can charge cheaply overnight and power your home at the evening peak, which saves money even when the panels produce little.
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