Can solar panels be damaged by hail?
While hail certainly could damage some types of solar panels, the likelihood is very small and occurrences are extremely rare. Many solar-electric modules and solar hot water collectors are made with tempered glass. Under standard test conditions they will withstand hail up to one inch in diameter, traveling at 50 miles per hour. Even in locations where larger hail does rarely occur, the hail is more likely to make a glancing blow to your array rather than a direct hit since panels are usually oriented at a tilt and facing south (in the northern hemisphere), which is most frequently not the prevailing direction for severe hail storms.
However, if you live in an area of the country where softball-sized hail is more common than in other areas and you are still a little nervous, you can make some further choices that will minimize your chances of damage. For solar electricity, consider using thin-film (or amorphous) photovoltaic panels. The substrate is a flexible plastic material and highly resistant to damage from rocks or hail. Any damage that does occur will not substantially affect the array’s performance. For solar hot water applications, flat plate panels or evacuated tube collectors can be mounted vertically on a south-facing wall where some shelter is afforded from the roof eave instead of the collectors being completely vulnerable on top of the roof.
In any case, damage to your solar equipment should be covered by your homeowner’s insurance policy, although you would be wise to review your policy’s coverage with your insurance agent in case you need to add a special endorsement.
— Linda Pinkham, former managing editor for Home Power Magazine