Module Imaging for Hail Damage Assessment and Two-Year Follow Up

Outdoor modules that have experienced golf-ball sized hail are characterized by flash testing and photoluminescence and electroluminescence imaging. These measurements were performed immediately after the hailstorm and then again after another two years in the field. The modules originally experienced different ranges of hail damage with some having cracks on approximately half of the cells and some having few to no cracked cells. Flash testing shows that the hail-damaged modules with the most cracked cells have 3 to 4% less power than those with the least damage. After two more years in the outdoor climate of Golden, Colorado since the hailstorm, all of the modules still exhibit similar power and amounts of cell cracking, suggesting that the hail damage has only initially reduced power but has not yet increased the degradation rate.