Spatial-Temporal Shading Under Mobile & Fixed Tilt Bifacial Agrivoltaic Panels & Implications for the Cropping Practices

Abstract

Spatial and temporal behavior of the incident sunlight can have important implications for agrivoltaic (AV) crop yield. We explore the daily and monthly variations of the photosynthetically active radiation (PAR) under various tracking and fixed-tilt agrivoltaic solar panels and propose strategies to minimize the shade-induced crop yield loss. Vertically installed solar panels facing East/West provide the best spatial homogeneity and a higher intensity of net daily incident PAR, while North/South faced fixed tilt panels result in a high spatial contrast, i.e., a significantly lower PAR underneath the panels as compared to the spacing between the adjacent panel rows. The shading behavior for the horizontal single axis tracking panels shows a seasonal dependence, a higher shading below the panels during winters and vice versa for summers. The spatial variation in the crop yield correlates well with that of the net daily PAR pattern in the case of the shade sensitive crops (e.g., tomato) while the spatial yield for the shade tolerant crops (e.g., lettuce) is less affected by PAR variations. We propose an intercropping approach using crops with high and low shade sensitivity to minimize the biomass loss related to PAR heterogeneity and present lettuce/tomato intercropping schemes under various agrivoltaic configurations