Estimating degradation rates from 27 different PV modules installed in desert conditions using the NREL/Rdtools

The performance degradation of 27 different types of PV modules installed for more than 2years in desert condition of Dubai has been reported. The new python-based tool known as NREL/Rdtools has been used to extract the degradation rate of all the PV modules. Sensor irradiancedata and clear-sky modeling approach have been used in this work. In general, mono-Si PV modules shows lower degradation compared to poly-Si and thinfilm technologies. The best performing PV modules are both mono-Si that showed degradation rate less than 0.07%/yr. The worst performing module was a CIGS with 3.9%/yr and a Poly-Si with 2.9%/yr. On an average, poly-SiPV modules showed 1.46%/yr degradation based on solar radiation sensors data while the use of a clear-sky based solar radiation model provides a lower figure of 0.55%/yr. The dominating degradation in poly-Si PV modules affects Isc, suggesting increased optical losses.