The temperature is dropping, and the days are getting shorter and maybe there’s a snowflake or two. It’s almost Winter. Maybe you have a solar array on your roof, or you’re thinking about one. Surely winter must be a bad time for solar, what with all the weather, and shorter days?
While it’s absolutely true that the shorter days mean that there is less time for solar production, believe it or not, solar panels work better when the temperatures are cooler! And solar arrays are typically snow load rated.
For example, Washington DC requires that all solar arrays are rated to a minimum snow load of 30 pounds per square feet. Most solar panels are actually rated to 120 pounds per square foot. What does that mean? Well-compacted snow will have a weight of about 15 cubic pounds, which means that 2 feet of compact snow has a weight of 30 pounds per square foot. However, your solar panels can handle four times that! The average snowfall in a city like Washington dc is 37 inches, so that would mean that solar panels can handle three times the average total snowfall.
What about hail?
Most modules are tested thoroughly. In fact the modules that we use are able to withstand firing hard pellets that are one inch in diameter at over 50mph. In fact in on May 9th 2017 the Denver metro area saw baseball-sized hailstones that caused a massive amount of damage.
However, just across the highway from a shopping mall that was closed for 9 months due to the damage, there is the NREL laboratory with 3,168 solar panels; and only one solar panel was damaged.