NREL: NREL Drops the Bass on Solar Panels (for Science)

National Renewable Energy Laboratory (NREL) researchers are not only skilled at making photovoltaic (PV) cells and modules. They are also world-class destroyers of PV modules. The goal is to discover and understand how these modules might degrade when installed outside for many decades. This helps other NREL researchers and engineers in the PV industry design better, longer-lasting modules.

Recently, NREL researchers, working with colleagues at the Electric Power Research Institute as part of a DuraMAT project, have been studying how small cracks in the solar cells inside modules might or might not cause power loss over time. On windy days, modules can flex and bend slightly, which could wear out cracked solar cells. Computer simulations have shown that the pressure cycles panels experience in real-world windy conditions are likely much smaller than those used in today’s reliability tests, so the researchers needed a new way to test this type of weathering in the lab.

Rather than installing modules outside and waiting years for the wind to act upon them, the NREL team found a faster way—powerful speakers. Strapped into a large wooden frame, PV modules are hit with rapid pulses of infrasonic sound waves (deeper in pitch than human ears can detect), causing them to vibrate. This mimics the effect of years of outdoor exposure in only a few hours or days.