Key takeaways
- • Plug-in solar in Great Britain is limited to a maximum output of 800W.
- • Savings depend heavily on how much electricity you use during daylight hours.
- • Permission may be required if you rent, lease or live in a managed building.
Yes. Solar panels need daylight, not heat, and the UK receives enough of it to make small systems worthwhile — just with a strongly seasonal profile.
What UK irradiance really looks like
Southern England receives roughly 1,000-1,100 kWh per square metre per year, Scotland closer to 750-850. A well-tilted 800W system therefore produces somewhere between 500 and 750 kWh annually depending on region, orientation and shading.
Summer versus winter
Expect roughly 60 percent of annual output between May and August, and very little in December and January. A vertical balcony mount narrows that gap slightly because low winter sun strikes it more directly.
Cloud, rain and cold
Panels still generate on overcast days, typically 10-25 percent of clear-sky output. Cold weather actually improves cell efficiency; it is the short days that limit winter yield. Rain keeps the glass clean.
Designing for the UK
- Tilt around 30-40 degrees where you can
- Prefer south, but east or west still delivers 80-85 percent
- Avoid any shading between 10am and 4pm
- Match consumption to generation to capture the value
Frequently asked questions
Sources
Fact-check status: reviewed. Read our editorial policy. General information only — not electrical, legal or financial advice.