NREL Helps Make Solar Panels Last

NREL Helps Make Solar Panels Last During 30 years on a rooftop, a solar panel gets bombarded by UV rays, soaked by rain, buffeted by wind, pounded by hail. What standards are needed for the glue in the edges that seal a panel's top and bottom? How does weather affect cracking? What can be done to prevent one glass panel from creeping away from the other? Solar modules must be sealed to keep out moisture - and that's why edge seals are so crucial. "We help manufacturers to know what sort of stress to put on their samples to determine if Sample A is better than Sample B," Kempe said. NREL scientist Michael Kempe exposes edge seals to different configurations and environments using Atlas Weather-Ometers. A typical 12-millimeter-wide edge seal should keep out moisture anywhere in the world - from Salt Lake City to Bangkok - if it maintains a good adhesion, Kempe said. On what looks like a whirling see-through geodesic dome - albeit just two feet in diameter - NREL scientists attach matchbook-sized samples that simulate the formation of PV modules to determine at what combination of UV radiation, high temperature, high humidity, and mechanical stress those samples can fail. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) plays a crucial role in improving the reliability of the photovoltaic (PV) panels that are being installed on rooftops in record numbers. NREL helps set standards for reliability and serves as a neutral third party in tests of manufacturers' new solders, edge seals, and glues. In March, leading scientists and engineers in the industry gathered at NREL for the PV Module Reliability Workshop. It's important that manufacturers not just check for single stresses. For humidity tests, NREL uses a vacuum oven to expose samples to controlled relative humidity using saturated salt solutions: lithium chloride for low humidity; magnesium chloride for 25% to 31% humidity; sodium nitrates for higher humidity. NREL Helps Make Solar Panels Last Trade News selected by Local Linkup on 12/06/2012