Yes, but much less
Solar panels work on light, not heat, so they keep producing on cold, bright days. What changes in winter is the amount of light. Days are short and the sun is low, so a Derby roof makes far less in December than in July.
PVGIS, the European Commission’s solar model, puts it in numbers. For each kWp of south-facing panels in central Derby, it gives about 121 kWh in July and about 34 kWh in December (PVGIS). A December output of roughly a quarter of July’s is normal, not a fault.
Month by month
For a 4 kWp south-facing system in Derby, PVGIS gives roughly:
| Month | Approx. kWh |
|---|---|
| January | 140 |
| February | 200 |
| March | 340 |
| April | 440 |
| May | 480 |
| June | 460 |
| July | 480 |
| August | 440 |
| September | 370 |
| October | 250 |
| November | 170 |
| December | 140 |
Most of the year’s output comes from April to September. That is why the yearly figure, about 979 kWh per kWp, matters more than any single month.
Snow and frost
A light frost usually clears as the sun comes up. Snow on panels blocks the light until it slides off or melts, and a pitched roof helps with that. Don’t climb onto the roof or use hot water to clear panels. The output lost on a snowy day is small compared with the risk.
Making the most of winter
In winter, you use nearly everything the panels make, because they make so little. The bigger saving comes from a battery charged overnight on a cheaper time-of-use tariff and used through the day and evening. Is a home battery worth it without solar panels? explains how that works, and solar battery storage covers fitting one.
When low output is a fault
If your system makes very little on a bright winter day, or nothing at all, check the inverter screen and the generation meter. A blank screen or a code on a sunny day is worth looking into. My solar inverter has stopped working covers the safe checks.