|Investigations of site-specific long term average albedo determination for accurate bifacial system energy modeling|
|Rhonda Bailey1, Patrick Keelin2, Richard Perez2, Justin Robinson3, Gwen Bender3, Julie Chard3
1Recurrent Energy, Walnut Creek, CA, United States
/2Clean Power Research, Napa, CA, United States
/3GroundWork Renewables, Sand City, CA, United States
Abstract — In recent years, bifacial modules have been attracting industry interest due to the potential for significant contributions to energy generation from the module rear side. Albedo is a critical parameter needed to determine rear side irradiation and accurate albedo values representing both long-term and evolving conditions are needed to quantify the impact of the additional energy generation for financing solar projects. In this paper, the authors identify multiple sources of long-term albedo data and compare to shorter term on-site measurements in Utah and California. An evaluation of on-site albedo measurement techniques is presented. Finally, we evaluate methods to reduce higher-frequency measured or long-term albedo data to monthly values commonly needed by industry-accepted software, such as PVsyst.