Yes, solar panels work in winter in England, but they make far less electricity than in summer. Our PVGIS modelling for a south-facing roof at 35 degrees shows Manchester producing 28.4 kWh per kWp in December against 108.8 kWh in June, about 26% of the summer figure. London manages 37.5 kWh against 122.5 kWh, about 31%. Across November to February, a typical English roof makes around 15 to 17% of its yearly total.
- About 4 kWh a day from a 4.4kW system in Manchester in December (125 kWh over the month)
- 15 to 17% of a year's solar output falls between November and February in the towns we modelled
- 26% to 31% December output as a share of June, from Manchester up to London
- Minus 0.26% per degree C is a typical modern panel's temperature coefficient, so cold panels are slightly more efficient, not less
That is the honest picture: winter solar is a useful top-up, not the main event. The reason it still matters is that almost every winter unit gets used in your home rather than exported, so each one is worth the full price you pay for grid electricity. Below we show the month by month numbers for four English cities, a worked winter example, and what snow, frost and cloud actually do.
Why panels make less in winter (and why the cold is not the problem)
Three things cut winter output. None of them is the cold.
- Short days. On the winter solstice London gets 7 hours 49 minutes of daylight, against about 16 hours 38 minutes at midsummer, according to Royal Museums Greenwich. Further north the gap is wider.
- A low sun. At midday in December the sun sits low over the southern horizon, so its light passes through much more atmosphere and hits your roof at a shallow angle. Nearby trees, chimneys and the house across the road also cast longer shadows.
- More cloud. English winters are grey, and thick cloud reduces the light reaching the panel much more than a thin summer haze.
Cold weather actually helps. Panels are rated at a cell temperature of 25 degrees C, and they lose a little efficiency for every degree above that and gain a little for every degree below. A current panel such as the LONGi Hi-MO X10 has a temperature coefficient of minus 0.26% per degree C. So a cell running at 5 degrees C on a crisp, bright January morning produces roughly 20 x 0.26 = 5.2% more power than the same panel would at 25 degrees C in the same light. That is why a clear frosty day can give surprisingly strong readings on your monitoring app.
Month by month: what a 4.4kW system makes in four English cities
The table below uses the PVGIS tool from the European Commission's Joint Research Centre, which combines satellite measurements of sunlight from 2005 to 2020 with local weather data. We modelled a 4.4kW system (10 x 440W panels) on a south-facing roof at 35 degrees, with standard system losses. The figures are kWh per month.
| Month | Manchester | Birmingham | London | Brighton |
|---|---|---|---|---|
| January | 116 | 162 | 178 | 184 |
| February | 202 | 227 | 232 | 260 |
| March | 347 | 378 | 388 | 435 |
| April | 456 | 476 | 506 | 583 |
| May | 504 | 522 | 536 | 613 |
| June | 479 | 515 | 539 | 640 |
| July | 477 | 524 | 549 | 651 |
| August | 422 | 465 | 484 | 567 |
| September | 357 | 399 | 425 | 473 |
| October | 246 | 272 | 298 | 318 |
| November | 168 | 187 | 211 | 205 |
| December | 125 | 148 | 165 | 173 |
| Year | 3,898 | 4,277 | 4,510 | 5,100 |
A few things stand out. December is the weakest month everywhere, with January close behind. The gap between north and south is proportionally bigger in winter: Brighton makes 38% more than Manchester in December, but only 34% more in June. And in all four cities, March and October are far better than people expect, which is why we tell customers to judge the system over a full year rather than over their first winter.
Across the 147 English towns we modelled, December output ranges from 23.3 kWh per kWp in Rochdale to 40.7 kWh per kWp in Chichester. You can see the figures for your own area on our pages for solar panels in Manchester, London and Brighton.
Worked example: a December day in Manchester
Take a 4.4kW system on a south-facing roof in Manchester, the least sunny of our four cities.
- Monthly output. PVGIS gives 28.4 kWh per kWp in December. 28.4 x 4.4 = 125 kWh for the month.
- Daily average. 125 kWh / 31 days = about 4.0 kWh a day. Some days will give 8 kWh, some dark, wet days less than 1 kWh.
- How much you use. In winter your home's daytime use (fridge, freezer, boiler pump, router, laptops, washing machine, lights on dull afternoons) usually soaks up most of that. Say 90% is used at home: 125 x 0.9 = 112.5 kWh.
- What it is worth. At the Ofgem price cap unit rate of 26.32p per kWh for October to December 2026, 112.5 x 26.32p = about £29.61 off your December bill. The 12.5 kWh you export earns a little more on top.
Now compare June. The same system makes 479 kWh, but a household out at work might use only a third of it directly, with the rest exported at a lower rate. Winter solar is small in volume but high in value per unit, which is why the annual saving matters more than any single month. For a full-year figure for your home, try our solar savings calculator.
Plan on the year, not the season: in Manchester, November to February produces 611 kWh of the 3,898 kWh yearly total from a 4.4kW system. The other eight months deliver about 84% of the output, so a quiet December is expected and does not mean anything is wrong.
Cloudy days, frost and snow
Cloud
Panels generate from diffuse daylight as well as direct sun, so a grey day still produces something. How much depends on how thick the cloud is: a bright overcast sky may give a respectable reading, while heavy rain cloud can cut output to a small fraction of a clear day. You do not need to allow for cloud separately in the figures above. PVGIS builds them from real historical weather, so an English winter's worth of grey days is already in there.
Frost
A frosty morning delays generation for an hour or so until the sun clears the glass. After that, cold, clear conditions are among the most efficient a panel sees all year.
Snow
A full covering stops generation. In practice, snow on a pitched roof tends to slide off smooth glass quickly, especially once any light warms the dark cells underneath. Please do not go up a ladder or onto the roof to clear it, and never pour hot water over the panels: the risk to you and the glass is not worth a few days of winter output. A properly designed mounting system allows for the weight of snow on the roof.
How to get more from solar in winter
- Run big appliances in the middle of the day. On a winter afternoon the useful window is short, roughly late morning to early afternoon. Set the dishwasher and washing machine to run then.
- Pair solar with a smart tariff. Some tariffs sell cheap electricity overnight. Intelligent Octopus Go, for example, offers six off-peak hours between 11:30pm and 5:30am at 8p per kWh. A battery can charge on that rate in winter, when the panels alone cannot fill it, and cover your evening peak. Our guide to the best energy tariffs for solar compares the options.
- Size the battery for the year. In December a 4.4kW system in Manchester makes about 4 kWh a day, most of which you use as it arrives, so it rarely fills a battery. Cheap overnight charging is what keeps a home battery earning its keep through the winter.
- Keep the monitoring app installed. A sudden drop compared with the same month last year points to a fault, a tripped isolator or new shading, not just the weather.
- Keep the panels unshaded. A tree that clears the roof in summer may cast a long shadow over it in December. Trimming it can make a real difference to winter output.
Does winter output change which roof you should use?
A little. Steeper roofs catch more of the low winter sun: in our PVGIS pitch runs for Birmingham, a south-facing panel at 45 degrees makes about 11% more in December than one at 35 degrees, while producing almost exactly the same over a full year. East and west roofs lose proportionally more in winter than south roofs, because the low sun spends most of the short day in the southern sky. If you have a choice of roof faces, south wins in every season, but an east and west split still works well over the year. Our guide on whether your roof is suitable for solar has the full orientation and pitch table.
The honest caveats
- PVGIS gives long-run averages. A particularly dull December can come in well below the table, and a bright one above it.
- Local shading is not in these figures. A roof overshadowed by a taller building or trees will lose more in winter than in summer.
- Your saving depends on your tariff. The unit rate we used is the Ofgem cap level for October to December 2026, a Great Britain average; your own rate may differ.
- Winter output will not heat your home on its own. A heat pump uses most of its electricity in exactly the months when solar makes least.
If you want to see how your own roof would perform through the year, we offer a free survey, in person or remotely using photos and satellite imagery, followed by a fixed written price. You can request a free solar quote online.
Sources
Monthly generation: our own modelling with PVGIS, European Commission Joint Research Centre (SARAH2 radiation data, 14% system losses, south-facing, 35 degrees). Unit rate: Ofgem energy price cap, October to December 2026. Day length: Royal Museums Greenwich, when is the winter solstice. Temperature coefficient: LONGi Hi-MO X10 product page and datasheet. Off-peak tariff: Octopus Energy, Intelligent Octopus Go.
