Most people think that solar panels don’t work in the snow. Indeed, solar panels cannot produce electricity if sunlight can’t reach them due to snow cover. The shorter days of winter also limit the output of solar panels compared to the relatively longer days during the peak of summer. However, the design of solar panels isn’t very conducive for the snow to stick around for long. Solar panels face the sun and absorb both its heat and light, and are usually mounted on a slope. So they work better during winter weather than you might think.
Solar Panels Shed Snow Pretty Easily
Solar panel installation includes mounting on an incline, maximizing their exposure to the sun. The surface of solar panels is slick glass, so snow already has a difficult time sticking to the angled and slick surface. But that’s not all that solar panels have going for them when it comes to shedding snow. They also have heat. The silicone cells of solar panel arrays are dark, which allows them to absorb heat from the sun. This absorbed heat is spread throughout a solar panel and quickly starts to melt the snow. All it takes is a small portion to be exposed and the heat from the sun will quickly spread and heat the rest of the panel.
One bonus to having snow on your solar panels is that it provides a passive cleaning service. Dirt build-up on your solar arrays prevents some sunlight from reaching the photovoltaic cells, which results in decreased performance. In drier parts of the country that receive little snowfall or rain, solar array customers often have to have their arrays washed.
Solar Panel Performance in Winter
Electricity production does indeed drop while your solar panels are covered with snow. However, the actual yearly productivity lost is smaller than you’d think. Solar panels are a great investment no matter how snowy the region in which you live is.
You might want to speed up the process of removing snow to get your solar panels operating at 100% efficiency. But experts warn against clearing snow off of your solar array yourself. Any damage you might cause to your solar panels most likely won’t be covered by the warranty. Also, the panels are usually mounted on sloped roofs that are potentially difficult if not dangerous to access. It’s best to just let the snowmelt.
Solar panels experience a drop in productivity from snowfall and shortening of daylight during the winter. But they perform better under winter conditions. The photovoltaic cells in your solar panels become more efficient under cold conditions. This is because electrical conductivity is improved the cooler it gets. So, while summer months provide more sunlight, colder months provide more efficient energy production. Additionally, snow is the most reflective natural substance that exists on the earth. Your solar panels can catch sunlight that is reflected from the surrounding snow cover.
Be Careful When Cleaning Snow From Solar Panels
If you feel that you absolutely have to get that darn snow cleaned off of your solar panels to optimize your system’s productivity, there are ways to do it. A roof rake can be used to clear the snow from the area directly below your solar panels. This will give the melting snow a place to go instead of just piling up at the base of each panel.
Don’t ever use a bare metal roof rake to clear snow from the panels themselves, however. This could damage the panels and would most likely void your warranty. Instead, you can attach a piece of foam pipe insulation to the end of the rake and use that to gently clean snow off of the solar panels. Some roof rakes on the market come with small rubber wheels that prevent the metal rake edge from contacting the surface of your solar panels. Be safe while you’re doing any snow removal on your roof; snow and ice are extremely slippery. The small boost in electrical productivity is not worth broken bones or worse.
Snow Won’t Set You Back
Luckily, most utility companies that you’ll work with offer net metering, which means that you’ll receive credit for excess electricity that you produce and send back to the grid. You can then use these credits to pay for electricity from the grid that you may need when your solar array is not producing or is less productive than normal. So you won’t need to worry during the night or after a blizzard dumps a ton of snow on your solar panels. Because of net metering and the credits you’ll receive for electricity produced, it is never of paramount importance that your solar system is always 100% efficient.