Sun Hours
Sun Hours for
Solar Panels
Enter your postcode. Tell Sol your best solar day. Get a 7-day solar forecast — no engineer, no complicated setup required.
How it works
Three steps to your solar forecast
Drop your pin
Enter a UK postcode or drop a pin anywhere on the map — Sun Hours works worldwide.
Your best solar day
Tell Sol the most kWh your panels have generated on their sunniest day. That single number tells Sol everything about your system.
7-day forecast
Sol does the rest — a personalised daily generation forecast, updated with live weather data.
See it in action
Simple. Clear. Honest.
No dashboards, no logins, no spreadsheets. Just your solar forecast, beautifully presented.
Today's forecast, the moment you open the app
Expected kWh, the best window to use it, and Sol's take on today — all on one screen.
See exactly where your solar goes
Home, battery, hot water, export — and what each day's generation is worth.
The best time to switch it on
Sol finds the window where an appliance can run on the most solar — sometimes 100%.
A month of generation, at a glance
Metered days against forecast days — and how accurate Sol's calls really are.
Share your day's generation
A clean, shareable card for today's number — as a still image or an animation.
How the whole country is doing right now
Live UK solar output, measured against the all-time generation record.
← swipe to explore →
No complicated setup
No inverter logins, no API keys, no degree in photovoltaics. If you've had solar installed, you're ready.
Real weather data
Live forecasts and historical irradiance data, updated daily.
Works anywhere
Optimised for the UK but useful anywhere the sun shines. Drop a pin, get a forecast.
Free Tool
Sun Hours Calculator
Enter any UK postcode or location to see today's peak sun hours — the key metric for how much your solar panels will generate. Download the Sun Hours app for a personalised kWh forecast with an hour-by-hour breakdown.
Solar Knowledge
Learn solar, with Sol
Solar Just Got “Offensively Cheap.” Predicting It Didn’t.
A new FT feature on the global solar boom is really a story about a forecasting problem — and it's exactly the one Sun Hours solves, just for your roof instead of a whole grid.
What Is a Solar Forecast, and Can You Actually Trust One?
What a solar forecast actually is, how accurate one can realistically be, and what to look for in a free solar forecast app — explained plainly, with our own numbers.
Warum Deutschland Europas Solar-Spitzenreiter ist (nicht wegen der Sonne)
1,3 Millionen Balkonkraftwerke, 120+ Gigawatt Solarleistung: Warum Deutschland Europas Solarmarkt anführt — obwohl die Sonne kaum eine Rolle spielt.