Simulation of the irradiance and yield calculation of bifacial PV systems in the USA and Germany by combining ray tracing and view factor modelEva-Maria Grommes, Felix Schemann, Frederik Klag, Sebastian Nows and Ulf BlieskeEPJ Photovolt., 14 (2023) 11DOI: https://doi.org/10.1051/epjpv/2023003