The majority of home roofs in North America are made from asphalt shingles. The shingles have a rough texture and give your roof friction that snow can “grip” – this prevents large amounts of snow from falling off your roof at one time.
Because solar panels are covered with glass, they are near-frictionless. When large amounts of snow accumulate on your solar panels, the snow may fall off your roof in large sheets. This amount of falling snow can hurt anyone standing below the roof and damage your outdoor furniture, vehicles, and anything else in the way.
If snow has accumulated on your solar panels, we strongly recommend you let the snow melt off your panels - brushing the snow off your solar panels may put you at risk of personal injury and falling snow can cause property damage. We also recommend you clear the area under your solar panels for falling snow.
Your solar panels are designed to handle snow. You should not be concerned about the weight of the snow on your solar panels.
If you live in an area with frequent heavy snowfall, you may want to ask your solar installer about snow guards. Snow guards are designed to hold snow on the roof, so the snow falls slowly or melts off the roof - no avalanche.