Effect of high biaxial solar trackers on crop yield, application to different design simulations

Abstract

The growing need in both producing renewable energy and food has led to the development of new systems such as agrivoltaic systems. Agrivoltaic systems, akin to agroforestry, integrate crop production in the understory with a photovoltaic overstory layer, casting spatial–temporal varying shades that can affect the yield of the understory crop by either improving or reducing crop growth underneath, depending on type of crop, pedoclimatic context, photovoltaic (PV) structure and its implementation design. Current studies on agrivoltaic arrays mainly evaluate global yield in areas under panels and in between panel and compare it to a control (ie. in full sun condition), and sometimes for various panels densities, but don’t consider shade gradients. The aim of this study was to assess field crops yields around high biaxial tracked PV installations, and correlate them with the spatial variations of shade, microclimate and soil parameters. This pattern was then used to simulate the crop yields under different designs. Two species of crops (wheat and maize) were monitored in 2022, 2023 and 2024, with a total of 44 trackers over 18 sites located in Western France. Received radiation (RR) appeared as the most impacting variable for both yield and biomass. Yields and biomass linearly decreased with decreasing RR, up to 45% and 40% respectively with a 50% RR decrease. However, relative maize biomass did not decrease much in 2022, probably due to an exceptionally hot summer. The simulated designs had Ground Coverage Ratios between 5 and 12% and induced limited global losses for both crops. Only the highest panel density with a Ground Coverage Ratio of 12% led to losses slightly greater than 10%.