Innovations in the durability of solar panels designed by researchers at the National Renewable Energy Laboratory in Denver passed with flying colors in real-world testing in the spring of 2017. Denver was pelted with an unusually severe hailstorm on May 8, leaving a trail of destruction in its wake, shattering car windows and leaving golf ball-sized dents on the roofs of local homes and vehicles. But of more than 3,000 panels installed atop NREL, which sat squarely in the storm’s path, a post-storm inspection revealed just a single broken panel. NREL’s panels generate more than 2.5 megawatts of power. NREL researchers work closely with other scientists through the U.S. Department of Energy’s SunShot Initiative to improve the durability of solar modules. Testing includes shooting ping-pong-ball-sized ice balls at PV modules in multiple places at about 70 miles per hour.