Performance assessment of bare and anti-reflective coated CdTe photovoltaic systems in comparison to multicrystalline Si in Brazil

The performance of three ground-mounted fixed-tilt photovoltaic (PV) systems installed at the Solar Energy Research Laboratory Fotovoltaica/UFSC in Florianopolis, southern Brazil (27 degrees S, 48 degrees W, Cfa Koppen-Geiger climate classification), were analyzed in this paper. This study compares the performance of cadmium telluride (CdTe) thin-film PV modules (both with and without an anti-reflective coating [ARC]) and multicrystalline silicon (mc-Si) PV systems over two full years of continuous operation. Furthermore, the paper presents a literature review on previous studies that investigated the main environmental parameters that affect the performance of CdTe and m-Si PV systems. Results revealed that throughout the period analyzed, the CdTe with ARC PV system presented the best performance, with an overall annual energy yield 5% higher than the reference mc-Si PV system. In order to evaluate the performance behavior of the three PV systems under study, the main environmental parameters that affect the efficiency of PV systems were analyzed: temperature, spectrum, angle of incidence, weak-light responsivity, and soiling impact. Irradiation levels for all PV systems were identical, as they are all operating at the same site. Temperature followed by spectral content of sunlight presented the highest impacts on performance, resulting in estimated overall performance gains of 1.9% and 1.5%, respectively, for the CdTe systems. These findings are consistent with our previous research, showing that CdTe has a performance advantage over traditional monofacial crystalline silicon technologies in warm and sunny climates.

Automated summary

The performance of three ground-mounted fixed-tilt photovoltaic systems in Florianopolis, Brazil was analyzed, with results showing that the CdTe with ARC PV system performed the best. Environmental parameters such as temperature and spectral content of sunlight were found to have the highest impacts on PV system performance.