Do Solar Panels Work on Cloudy Days and at Night?
One of the most common solar questions: if I live somewhere cloudy, is solar even worth it? The short answer is yes - panels still work in clouds, just at reduced output. Here’s what actually happens in different conditions.
Cloudy days: less power, not zero
Solar panels run on light, and plenty of light still reaches the ground through clouds. On an overcast day, panels typically produce roughly 10-25% of their sunny-day output - less, but far from nothing. Light cloud or haze cuts output only modestly.
This is why solar is viable even in famously cloudy places: Germany, one of the world’s leading solar markets, gets less sun than most of the US. What matters for your savings is your total annual sunlight (and your electricity rate), not whether every day is clear.
At night: no production
Panels need light, so at night they produce nothing. Your home covers nighttime use in one of two ways:
- The grid, drawing on credits you banked during the day through net metering, or
- A battery, which stores daytime surplus for use after dark - see do I need a solar battery.
A standard grid-tied system without a battery also shuts off during a blackout for safety - so panels alone won’t keep your lights on in an outage.
Heat, cold, and temperature
A common misconception: panels love heat. They don’t. Panels run on light, and they’re actually slightly more efficient in cool temperatures. Very hot panels lose a little efficiency - which is why a cold, sunny winter day can be surprisingly productive.
Snow
Snow that covers panels blocks production until it slides or melts off - which usually happens quickly, since panels are dark, tilted, and warm slightly in daylight. Annual snow losses are typically small for most homes.
Rain (a hidden benefit)
Rain actually helps - it rinses dust and pollen off the panels, keeping them clean and efficient with no effort from you.
What this means for your decision
- Cloudy climate ≠ skip solar. Judge by annual sunlight and your electricity rate, not by how gray it feels.
- Seasonal swings are normal. You’ll produce more in summer, less in winter; net metering smooths this out across the year.
- Want power at night or in outages? That’s a battery decision, not a panel one.
Whether the numbers work for your specific home comes down to your annual production and rates - see is solar worth it in 2026.
Bottom line
Solar panels work on cloudy days at reduced output (~10-25%), produce nothing at night, and actually run a touch better in the cold. Clouds and weather lower production but rarely make solar a bad idea - your annual sunlight and electricity rate are what really decide the savings.
Educational information only, current as of June 2026. Output percentages are typical ranges and vary by panel, location, and conditions.