Long-termin degradation assessment of five different photovoltaic technologies in Austria

A PV rooftop test stand with five different PV module technologies is in operation at the University of Applied Sciences Upper Austria at Wels Campus since June 2007. This study aims to evaluate the long-term outdoor performance of each photovoltaic array utilizing measurement data of the ten-year period from 2009 to 2019, identify possible causes that led to underperformance, and determine the degradation rate of modules. The degradation rate of each PV array was calculated using two different meteorological datasets. The first dataset is based on the meteorological measurement station on the roof of the university building at Wels Campus, the second dataset is from SolarGIS. For the determination of the degradation rates, two different methods were applied: the trend of normalized energy and the classical seasonal decomposition statistical (CSD) method.