Bifacial PV plants: performance model development and optimization of their configuration

Abstract: Bifacial solar modules can absorb and convert solar irradiance to current on both their front side and back side. Several elements affects the bifacial yield, especially the ground albedo around the system or the installation configuration. In this document, investigations carried out at EDF R&D facilities regarding the use of bifacial modules in large scale PV farm are presented. Tests on the outdoor facilities were conducted to validate and improve a bifacial stand model developed under a Dymola/Modelica environement. Furthermore, a global optimization method was implemented to determine the optimal configuration of a large bifacial plant with modules facing south. Investigations showed the importance of a new albedo model to accurately evaluate the irradiance received on the rear side. The new model shows a relative error on the rear irradiance under 5% when compared with experimental data. Techno-economical optimization of a bifacial plant was conducted at different locations and for different ground albedo. The results shows that the gain on the specific production can vary between 7.2 and 14.2% for a bifacial plant when compared with a monofacial plant. Bifacial plants are expected to become more profitable than monofacial plants in some of the cases tested when their module cost will reach 68 c€/Wp.