On May 8, the Denver area was hit with a hailstorm of unusual severity. It left behind a trail that included shattered car windows, golf-ball-sized dents on roofs, and shattered glass on cars.
The National Renewable Energy Laboratory staff set out to assess damage after the storm. The main campus of the National Renewable Energy Laboratory in Golden, Colorado, has more than 2,5 megawatts worth of photovoltaic power. Most of these panels (more than 3,000) are located on or near the roof of the Research Facility of the lab, a net zero energy building. Only one meeting was damaged during the post-storm inspection.
PV Strong
Researchers at NREL weren’t surprised by this news. The NREL researchers work closely with the SunShot initiative of the U.S. Department of Energy to improve the durability of solar modules. The testing includes requiring the solar modules to survive the impact of hail stones. The test involves shooting ping-pong ball-sized iceballs at PV modules at 70 miles per hour in several places. In this case, the glass module cover appears cracked when simultaneously struck by several hailstones at almost the exact location. The concentrated impact created a web of micro-cracks on the glass. The subsequent hailstones left their “footprints,” which appear to be over three dozen hits, in the web of micro-cracks.
SunShot funds NREL researchers to participate in the International Photographic Quality Assurance Task Force. This group develops industry-standard quality tests that ensure solar panels can withstand the harsh conditions they face. The tests include not only the response of the panels to mechanical stress, such as being walked on or hail, but also to high and low temperatures and humidity, ultraviolet solar radiation, and the electrical stress they apply themselves in high-voltage systems. These standards reinforce the confidence of consumers and investors in PV.
NREL is also the leader of a group that brings together national laboratories and universities and the solar supply chain industries to discover, develop and de-risk new materials and designs. This will enable commercialization. The durable modules materials consortium is focused on accelerating research and development for high-performance PV packaging and module architectures to increase module performance and reliability while reducing module costs. This will improve the performance and durability of solar panels while lowering the cost of solar energy.
NREL research shows solar energy systems can withstand extreme weather conditions like hurricanes and hail. The events of May 8, however, further highlight the benefits of solar.