What about hail damage?

Solar panels are made with a tempered glass. This glass is tested at a perpendicular angle and is rated to take a 1" hail at 88kph. That's just a bit smaller than a golf ball. In reality, a perpendicular hit is rare due to the fact that most arrays are set at an angle. This makes hail damage very rare in Alberta. The only known time that hail damaged solar panels in Alberta was in 2012 in the southern town of Cardston where the hail was the size of tennis balls.