The Short Answer
Yes, but they make a lot less. On PVGIS's long-term averages, a 4kWp south-facing system in the Midlands makes about 4.8 kWh on an average December day, 32% of an average June day (15.2 kWh). November to February together bring only about 18% of a year's output, against 67% from April to September.
Where you live matters more in winter than in summer: an average December day ranges from about 2 kWh in Inverness to 5.2 kWh in London and South East for the same system. Panels still work under cloud, as the Energy Saving Trust says, just less. Size your expectations on the summer, and treat winter output as a top-up.
What Yours Makes in Winter
Pick where you live, your system size and a winter month. The daily use starts at Ofgem's typical 2,500 kWh a year, spread evenly; put in your own from a bill if you know it.
Winter solar calculator
What your panels make on an average winter day
PVGIS long-term averages for eight UK places, south-facing panels at 40 degrees.
Average day in December
4.8 kWh
32% of an average June day (15.2 kWh), and about 71% of the 6.8 kWh you use.
Over the month: about 149 kWh, worth up to £39 at Great Britain's price cap rate if you use all of it.
These are averages over 2005 to 2020, so real days vary either side of them. East, west or shaded roofs make less than this.
Winter Output Across the UK
PVGIS averages for 4kWp of south-facing panels at 40 degrees, over 2005 to 2020:
| Place | Average December day | Average June day | December as a share of June |
|---|---|---|---|
| South West England (Plymouth) | 4.8 kWh | 17.2 kWh | 28% |
| London and South East | 5.2 kWh | 16 kWh | 33% |
| South Wales (Cardiff) | 4.4 kWh | 16.8 kWh | 26% |
| Midlands (Birmingham) | 4.8 kWh | 15.2 kWh | 32% |
| North West England (Manchester) | 4 kWh | 14 kWh | 29% |
| Northern Ireland (Belfast) | 3.6 kWh | 15.2 kWh | 24% |
| Central Scotland (Edinburgh) | 3.2 kWh | 14.4 kWh | 22% |
| Highlands (Inverness) | 2 kWh | 13.6 kWh | 15% |
The winter drop varies a lot: Inverness's December day is 15% of its June day, London and South East's 33%. East or west-facing and shaded roofs make less than these figures. These are PVGIS's own figures for each place; our year-round guides scale the Midlands profile to the 950 kWh per kWp a year we use site-wide, so they show slightly less for the Midlands (about 4.7 kWh on a December day).
Do Solar Panels Work on Cloudy Days?
Yes. The Energy Saving Trust says solar cells don't need direct sunlight to work and can even work on cloudy days, though the more sunshine, the more electricity. That's why the averages above are well above zero even in the greyest months: they include the dull days as well as the bright ones. A single overcast winter day makes less than the average, and a clear one more.
Snow and Dirt
Don't go up on the roof to clear snow or clean panels. The Energy Saving Trust's advice on solar maintenance is that it's always safer to avoid working at heights without the right training or equipment, and that rain does a good job of keeping rooftop panels clean. If your panels sit under trees or collect a lot of dirt, a professional clean is the safe option: our solar panel cleaning guide has the details.
Getting the Most From Solar in Winter
- Use it while it's light. Panels only generate in daylight, so running the washing machine or dishwasher during the day uses your own solar rather than the grid.
- A battery can work in both seasons. In summer it stores your own solar; in winter, when there's little spare, it can fill up on a cheap night rate instead. On Octopus Flux (average of its regions, 24 October 2026), the overnight rate was 16p a kWh against 26.5p in the day and 37p at the 4pm to 7pm peak. Our solar battery guide runs the numbers.
- Don't count on solar for winter heating. A heat pump uses most when panels make least. Our guide to solar panels with a heat pump shows how much it covers across the year.
For what a system makes through the whole year, and what it can run, see what can solar panels power; for payback, are solar panels worth it.
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