Solar panels still produce meaningful electricity in winter — on a clear January day, a 6 kW residential system in the US can generate between 12 and 24 kWh depending on latitude and local sunshine hours. That range surprises many homeowners who assume shorter days and snow mean their system goes. These are the factors influencing a solar panel's output- 1. Atmospheric Conditions Winter means more cloudy days, rainy and snowy days. The sunlight exposure hours for the solar panels considerably reduce to a large extent. A 6 kW residential system produces about 25 kWh/day. However, contrary to popular belief, cold and snow can actually have a positive effect on performance.