PV MODULE POWER GAIN DUE TO BIFACIAL DESIGN. PRELIMINARY EXPERIMENTAL AND SIMULATION DATA

Tests and subsequent simulation are needed for rational use of bifacial instead of traditional mono facial modules for generation of additional energy. Outdoor measurements of bifacial modules were undertaken at Jerusalem (similar to 32 deg. of North altitude). Method of determining nominal electrical parameters (I-sc and P-max) for each side of the module is proposed. The relationships of back module irradiance and Isc, Pmax generation are studied for different climatic and design conditions: diffusion/global ratio of sun illumination, seasonal sun position, module elevation above the mounting surface, tilt panel angle, and reflectance of the underlying surface. Non uniformity of back illumination and module elevation are among factors dramatically affecting the energy gain when using bifacial modules.