Performance assessment of solar photovoltaic technologies under different climatic conditions in Brazil

Utility-scale photovoltaic (PV) generation is being ramped-up in Brazil in recent years, as a result of intense price reductions. Extreme operating temperatures, high humidity levels, and a blue-biased distribution of irradiance in comparison with the standard ASTM G-173 spectrum, lead to contrasting operational outputs of the various commercially-available PV technologies. The performance assessment of six different PV technologies installed at eight different climatic regions in Brazil is presented. This R&D project evaluates eight identical, 54 kWp Evaluation Sites (ESs), all with the following PV technologies: amorphous-silicon (a-Si), microcrystalline-silicon (μc-Si), cadmium-telluride (CdTe), copper-indium-gallium-diselenide (CIGS), mono- and multi-crystalline silicon (c-Si and m-Si). All installations operate at a fixed-tilt equal to the corresponding local latitude. Electrical and environmental parameters at all sites are measured continuously at 1-s intervals. Results show a detailed energy loss analysis for all technologies. Thin-film PV modules with a low temperature-coefficient of power presented superior performance. Crystalline silicon modules revealed intense degradation in areas with high relative humidity and temperature. Cloud-edge and cloud-enhancement effects of solar irradiance resulted in irradiance peaks of 1823 W/m2, with long overirradiance events which lasted many minutes over 1600 W/m2, resulting in frequent blowing of string fuses when manufacturers maximum fuse ratings were observed.