One of the most common reasons Brits talk themselves out of solar is the weather. "It's cloudy half the year here." Good news: panels run on daylight, not direct beams of sun, and daylight gets through clouds just fine.
Clouds dim the light, they don't block it
On a heavily overcast day a panel typically makes 10 to 25 percent of its sunny-day output (light or hazy cloud, much more). That's a dip, not a shutdown — your roof is still generating power whenever it's bright enough to read a paper outside.
Annual numbers are what count
Systems are sized around a whole year of weather, grey days included. Germany — hardly the Mediterranean — runs more solar than almost anywhere, precisely because the maths already accounts for the clouds.
Sunny says
If your area is especially dull, the fix is usually a slightly larger array or a battery to stretch the sunny hours — not skipping solar altogether.
The quick version
- Panels still produce 10–25% on a heavily overcast day.
- Year-round totals matter more than any single day.
- Cloudy regions can absolutely make solar pay.