Short answer: yes. Panels make less power in winter because days are shorter and the sun is lower, not because it’s cold. On heavily overcast days they still produce roughly 10-25% of their normal output, according to EnergySage. Snow is the bigger issue in northern states, costing up to about 16% of yearly output in the snowiest areas.
Cold is good, short days are not
Solar panels convert light, not heat, into electricity. They actually run a little more efficiently when they’re cool; hot summer days slightly reduce output. Clear, cool days are when panels perform best.
What really cuts winter production:
- Fewer daylight hours.
- A lower sun angle, so the same panel catches less light, and nearby trees or buildings cast longer shadows.
- Cloud cover, which is more common in winter in many regions.
- Snow sitting on the panels.
How much snow really costs
An NREL study modeled snow losses for fixed solar arrays across the continental U.S. and found annual losses from 0% to about 16% (NREL, 2017).
| Location (examples from the study) | Annual snow loss |
|---|---|
| Phoenix, Arizona | none |
| Flagstaff, Arizona | about 3-5% |
| Snowiest areas of Minnesota and Michigan | up to about 16% |
Snow slides off tilted, dark panels once the sun warms them, so losses are usually measured in days, not months. Don’t climb on the roof to clear panels; a fall or a scratched panel costs far more than a few days of output.
Why cloudy places still go solar
San Francisco, famous for fog, and rainy Seattle are both strong solar markets, EnergySage notes. The reason is money, not sunshine: when electricity is expensive, each kWh a panel produces is worth more. A system in a cloudy, high-rate city can pay back as fast as one in a sunny, cheap-power state. Our solar cost guide shows how the electricity rate drives payback.
Net metering smooths out the seasons
If your utility offers net metering, extra power from long summer days earns credits that offset smaller winter production. How generous those credits are varies by state; read net metering, explained before you size a system around winter.
How to estimate your own winter output
- Go to NREL’s free PVWatts calculator.
- Enter your address, system size, roof tilt and direction.
- Look at the monthly table: in northern states, December output is far below June output; the tool gives your own month-by-month estimate.
- Compare annual output with your yearly usage, not just one month.
FAQ
Do panels work at night? No. At night you draw from the grid or a battery.
Should I remove snow? Usually not. If you do, use a soft roof rake from the ground and never hot water.
Does solar make sense in the North? It can, when electricity rates are high and the roof faces south without shade.