Insights on the Degradation and Performance of 3000 PV Installations of Various Technologies Across the UK

This article presents the degradation rates over eight years for 3000 PV installations distributed across the UK. The study considers three PV cell technologies, namely, monocrystalline silicon (Mono-Si), polycrystalline silicon (Poly-Si), and thin-film Cadmium Telluride (CdTe). The available raw data undergoes three key stages: normalization, filtering, and aggregation, before the degradation analysis of the considered installations. This algorithm can be considered as one of the paper contributions. Results show that a maximum degradation rate of -1.43%/year is observed for the CdTe type, whereas Poly-Si and Mono-Si PVs have annual degradation rates of -0.94% and -0.81% respectively. Moreover, this article exploits the monthly mean performance ratio (PR) for all the examined PV sites. The highest PR value of 87.97% is calculated for the Mono-Si PV installations, while 85.08% and 83.55% is calculated for Poly-Si and CdTe installations, respectively.