5. 3 Operation, Performance and Maintenance of PV Systems
Bifacial, Shading, Structure, Factor, Mismatch Factor, Loss factor
Summary / Abstract:
We investigate the energy gain driven by bifaciality in PV plants designed for trackers in 1P (Portrait) and 2P configurations. For that purpose, three elements have been experimentally analyzed: 1) The rear shading caused by the tracker’s mounting system (torque tube and panel rails). This is characterized by the so-called Structure Shading Factor, SSF, defined as the share of rear irradiance that is obstructed by the structure -an input parameter required by PV software (SISIFO, PVsyst...) for energy yield estimations-. 2) The mismatch losses on the electric power delivered by the PV array due to the non-uniformity of the rear irradiance. This non-uniformity is partly due to the nature of the radiation reflected by the ground and partly to the shading caused by the tracking structure. Mismatch loses are characterized by a factor, MML, which quantifies either the total power reduction delivered by the PV array or just the power reduction corresponding to the rear irradiance. 3) The solar cell operation temperature. We paid especial attention to analyze the temperature differences between East and West module rows in the 2P tracker, compared to the temperature of the modules in the 1P tracker.