Light snow has little impact on solar panels because it easily slides off. It’s a different story when heavy snow accumulates, which can limit the amount of energy produced by PV panels. But while snow accumulation does block some light from reaching the solar circuit, light is still able to move through the snow and forward scattering brings more light to the solar cells than one might expect. So, even when panels are completely covered, they can still generate electricity.

Heavy snowfall can present a problem when the weight of the snow places stress on a PV system’s support structure. The majority of PV panels in the field today have frames, which tend to create localized stresses at the mounting points. At the Vermont Test Center, researchers are characterizing impacts such as microcracks formed by the non-uniform load of the snow. As can be seen in this article’s main photo, the absence of a frame allows the snow to slide off. This research has the potential to make solar a more economic option for energy generation in northern climates.

With or without frames, though, it’s important to note that snow can actually help clean a PV module as it melts away. It’s similar to what happens to a car’s windshield: If the snow is allowed to melt off, the windshield is left without a speck of debris. That’s because any dirt on the glass will bond with the snow, washing it away when the sun melts it off. The anti-soiling properties of snow inherently make solar panels cleaner and able to reach higher efficiencies.

his winter, even if the snow piles high, we can remain confident that our solar panels will generate power and that research conducted at the Regional Test Centers will help PV perform even better in the future.