Photovoltaic fleet degradation insights

In the PV Fleet Performance Data Initiative, high-frequency data from commercial and utility-scale photovoltaic (PV) systems have been collected to examine performance loss rates (PLRs) at a fleet scale. To date, performance data from more than 7.2-gigawatt (GW) capacity, 1700 sites and 19,000 inverters-approximately equivalent to 6% to 7% of the entire US PV market-have been collected. An overall PLR of -0.75%/year was found, which is in line with historical and recent findings. Tracked silicon (Si) and cadmium telluride (CdTe) performed comparably with all fixed-tilt systems. Higher PLRs were found for hotter temperature zones; cooler climates exhibit a median -0.48%/year loss, which increases to -0.88%/year in hotter climates. High-efficiency module technologies showed median PLRs in line with conventional Si technologies but demonstrated markedly different PLR behavior when filtered only for low-light conditions <600 W/m(2). Causes for this technology-dependent behavior are under investigation.