The short answer
Yes, but not much. The UK gets about 43 hours of bright sunshine in an average December, against about 172 in June (Met Office, 1991–2020). Using the EU's PVGIS solar model, a 100 W panel fixed facing south at a steep angle averages roughly 90 to 140 watt-hours a day in December, depending on where you live, and about 310 to 340 in June. Laid flat, the December figure in London drops to about 50. On a dull winter day it can be far less. Treat a winter solar panel as a top-up for phones and power banks, not a way to run a fridge.
The short answer
A portable solar panel does charge things in a UK winter, but only a little, and much less than the number on the box. The "100 W" rating is what it gives in strong, direct sun under test conditions. A short, grey December day is nothing like that.
Winter sun in numbers
The Met Office's UK sunshine records show how big the gap is. Averaged over 1991–2020, the UK got about:
| Month | Hours of bright sunshine (UK average) |
|---|---|
| December | 43 |
| January | 48 |
| March | 109 |
| June | 172 |
| July | 173 |
So December has about a quarter of June's sunshine, and the days are short too. (These are our averages from the Met Office's published UK series.)
What a 100 W panel gives: modelled figures
We used PVGIS, a free solar model run by the European Commission's Joint Research Centre, to estimate the average daily output of a 100 W panel. We set it to face due south at a 60-degree tilt, with no shade and PVGIS's standard 14% allowance for losses.
| Place | December | March | June |
|---|---|---|---|
| London | about 140 Wh a day | about 280 Wh | about 340 Wh |
| Manchester | about 110 Wh | about 250 Wh | about 310 Wh |
| Edinburgh | about 90 Wh | about 260 Wh | about 320 Wh |
Read these with care:
- They are monthly averages from a model, not tests of any product. Some December days will give a few watt-hours; a rare clear day gives more.
- They assume the panel stays put, facing south, all day. A panel you put out for a couple of hours will give less.
- They don't include losses from cheap cables, USB charging, a power station's own charging, glass or shade. Real results from a portable kit are likely to be lower.
Angle matters more in winter
The winter sun is low in the sky. In the same PVGIS model for London in December:
| How the panel is set | December average |
|---|---|
| Lying flat | about 50 Wh a day |
| Tilted at 60 degrees, facing south | about 140 Wh a day |
| Standing upright, facing south | about 140 Wh a day |
So prop it up steeply and point it south. Lying flat on a table or the ground cuts the winter output to about a third. Keep it out of shade from trees, fences and buildings, and wipe off rain, dirt and frost.
What that energy can do
A rough guide, using the London December model figure of about 140 Wh on an average day:
- Phones and a power bank: yes. A 20,000 mAh power bank holds roughly 74 Wh at its battery's own voltage (20,000 mAh × 3.7 V; our arithmetic, and charging loses some). So an average December day might refill about one, if everything goes well. A dull day may only give a partial top-up.
- LED lights and a radio: yes, through a power bank or power station.
- A Wi-Fi router for a few hours: possibly, through a power station; check its watts on the label.
- A fridge or freezer: no, not from one panel in winter. Fridges use far more over a day. Keep the door shut instead: the Food Standards Agency says a closed fridge stays cold for up to 4 hours and a full freezer for up to 48. Our power station post has the sums.
- Heating: no. Electric heaters use far too much.
Our runtime calculator works out what a battery will run once you've charged it.
Practical tips
- Charge into a battery, not straight into a phone. Clouds make the output jump about; a power bank or power station smooths that out.
- Check the plug fits your power bank or power station before you need it. Many panels have USB-C and a separate DC output.
- Charge everything before a storm. Be Ready's advice is to charge phones, power banks and medical device batteries when a storm is forecast. A panel is the back-up, not the plan.
- Don't leave it out in a storm. Wind can lift a folding panel. Bring it in.
- Summer is different. In the model, the same panel gives roughly two and a half (London) to three and a half (Edinburgh) times as much in June as in December, which makes it more useful for long outages then.
Rooftop solar is a different question
If your house has solar panels on the roof, they usually switch off in a power cut for safety. See why rooftop solar doesn't work in a power cut.
How we got these numbers
- Sunshine: Met Office HadUK-Grid UK areal series of monthly sunshine hours, file last updated 1 October 2026. We averaged each month over 1991–2020.
- Solar output: PVGIS 5.3 (SARAH3 radiation data), run on 1 November 2026 for London (51.51 N, 0.13 W), Manchester (53.48 N, 2.24 W) and Edinburgh (55.95 N, 3.19 W): 0.1 kW peak, 14% system loss, south-facing, at 60 degrees (and 0 and 90 degrees for London). Figures are the model's average daily energy for each month, rounded to the nearest 10 Wh.
- We haven't tested any panel. Product listings in the box below show prices read on 1 November 2026; we don't rank them.
What to buy
About these links: plain links to ordinary retailer pages. We may earn from some links in future; we don't now. We haven’t tested these and we don’t rank them: they are examples that were in stock when we checked. Prices change. Check what you already own first. Full kit list
Folding solar panel (optional)
Look for: Check the plug fits your power station or power bank. Expect much less than the rated output on short, cloudy UK winter days.
Power bank
Look for: From a seller you know. Check the capacity (mAh) against your phone, and that you have the right cable for each phone. Keep it charged.
- Anker Zolo Power Bank 20000mAh 30W Built-in USB-C · Anker UK (brand store) · £34.99 (price on 1 November 2026) Shop
- Anker Zolo Power Bank 20000mAh 30W Built-in USB-C · Amazon UK · £28.99 (price on 1 November 2026) Shop
- Anker Power Bank 20K 87W Built-In USB-C Cable · Anker UK (brand store) · £49.99 (price on 1 November 2026) Shop
Portable power station (optional, bigger budget)
Look for: Check the capacity in watt-hours (Wh) and the continuous AC output in watts against what you want to run. Our runtime calculator does the sums.
- Jackery Explorer 300D Portable Power Station · Jackery UK (brand store) · £219.00 (price on 1 November 2026) Shop
- EcoFlow RIVER 2 MAX 512Wh LiFePO4 · Amazon UK · £449.00 (price on 1 November 2026) Shop
- Jackery Explorer 1000 Plus v2 Portable Power Station · Jackery UK (brand store) · £599.00 (price on 1 November 2026) Shop
- Jackery Explorer 1000 v2 1070Wh LiFePO4 · Amazon UK · £469.00 (price on 1 November 2026) Shop
Frequently asked questions
Do solar panels charge anything in a UK winter?
A little. In the EU's PVGIS model, a 100 W panel facing south at a steep angle averages about 140 Wh a day in London in December, and about 90 Wh in Edinburgh. That's an average: dull days give much less. Enough to top up phones and a power bank, not to run big appliances.
Which way should a solar panel face in winter?
South, and steep. In the PVGIS model for London in December, the same 100 W panel gives about 140 Wh a day at a 60-degree tilt or standing upright, but only about 50 Wh lying flat. The winter sun is low, so tilt the panel up towards it and keep it out of shade.
Can a solar panel run my fridge in a winter power cut?
Not on its own. A 100 W panel in December averages roughly 90 to 140 Wh a day in the model. A fridge usually needs far more than that over a day; check its label. A charged power station and keeping the fridge door shut matter more.
Will a solar panel charge through a window?
Less well. Glass, screens and window frames cut the light, and the model figures here don't include them. Outside, tilted south and out of shade, is best.
Is a solar panel worth buying for power cuts?
Only after the basics: a torch, a battery radio and a charged power bank. A panel helps most in long power cuts and from spring to autumn. In winter it's a small top-up.
Sources
We opened each page on the date shown. Official advice changes: if a source says something different now, follow the source.
- Met Office: UK monthly sunshine duration, HadUK-Grid areal series (UK.txt, last updated 1 October 2026); our averages for 1991–2020 (read 1 November 2026)
- European Commission Joint Research Centre: PVGIS 5.3 (photovoltaic performance tool, SARAH3 data); our model runs for London, Manchester and Edinburgh (read 1 November 2026)
- GOV.UK Be Ready: power cuts (read 1 November 2026)
- Food Standards Agency (GOV.UK): Food safety in a power cut (read 1 November 2026)
Related guides
- Do you need a portable power station for power cuts?
- How many phone charges will a power bank give you in a power cut?
- Power cut kit: what to keep in one box, and how long power cuts last
- Will there be blackouts this winter? What the 2026/27 outlook says
Free tools
We're an independent UK site, not the government. We check guides against official sources and link to them. In an emergency call 999.
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