This is the number one question we get about the impact of winter, having your panels entirely covered with snow does mean they won’t be able to produce the energy you want from them but there are a few factors to consider. Here in Wisconsin, the vast majority of our solar installations are placed at an angle that optimizes their orientation to the sun. This not only means that snow will slide off of them faster than other surfaces but also that they will be exposed to the sun more and correspondingly heat up faster.
If 80,000 people can pack into Lambeau Field when it’s negative fifteen outside then your solar array will be fine as well. Actually, solar panels will have a better performance in cold temperatures. You can see how much this applies by looking at the “Temperature Coefficient” which is listed on the manufacturer’s spec sheet for your panels.
Grey Skies and Clouds:
Overcast skies are the reality of winter up here that is hard to ignore. When it’s all white clouds above your solar panels will not be getting the direct sunlight that allows them to optimize their
energy production. That doesn’t mean they are sitting there useless though; indirect solar radiation does filter through the clouds and hits your panels. Modern solar panels are getting incredibly efficient at converting any amount of solar radiation into energy but there is no way to avoid the loss that comes from increasingly cloudy skies.
Winter is part of life in Wisconsin and that means that we have to live with it in all areas,
including solar energy. However, when you look at the impact of loss to the elements for your solar it’s important to remember that the losses to snow or clouds are occurring during the darkest and shortest months of the year. This far north the days get shorter and darker from November to March and we factor that into our design and estimating for all of our solar projects. By optimizing the production in the long days of summer and accounting for the short days of winter you don’t need to worry about the season since it’s all been taken into account. That’s the benefit of working with your local experts.