A detailed look into the performance of bifacial solar arrays in Delaware's climate

Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
This paper studies the effectiveness of bifacial solar arrays in Delaware’s climate, analyzing several factors that influence the anticipated benefits of using bifacial modules over their monofacial counterparts, with the goal of advising future solar installers and to see if bifacial modules would be beneficial in an upcoming agrivoltaic project. We compared the effects that white tarps, black tarps and gravel had on array output, and covered the rear sides of two modules, making them monofacial, then comparing them to their bifacial neighbors to quantify the benefit of rear surface light collection. Over the course of the year, the covered modules produced 9.99% and 9.93% less energy and were between 1.5% and 3.5% less efficient than their bifacial counterparts depending on the ground cover. High albedo ground covers like the white tarps increased the disparity between the power production and efficiency of the covered versus uncovered modules as the increased insolation on the rear side causes the uncovered modules to produce more energy. Additionally, the impact of inverter clipping on the bifacial gain was analyzed, with white tarps providing the highest bifacial gain in all categories. On days with inverter clipping, a lot of the bifacial gains were eliminated, but still provided gains between 5-6% for white tarps. On days without clipping, the bifacial gain from white tarps reached as high as 16.7%, vastly outperforming the other ground cover types for similar conditions. Overall, the effectiveness of bifacial modules and the benefits that come with increasing the albedo of the ground cover underneath the array were analyzed and proven, especially for cloudy and winter days where the bifacial gains were not partially eliminated by inverter clipping.
Description
Keywords
Arrays, Efficiency, Monofacial counterparts, Black tarps, Agrivoltaic project
Citation