Optimization of Single-Axis Tracking of Photovoltaic Modules for Agrivoltaic Systems

摘要

Agrivoltaics is an emerging technology of collocating solar photovoltaics with agriculture that has many potential synergetic food-energy-water benefits. The design of agrivoltaic systems demands a careful balance for sharing sunlight between solar panels and crops to ensure an optimal food-energy productivity. We explore the optimal single-axis tracking schemes for agrivoltaics that can provide the precise balance of sunlight between PV and crops. The single-axis tracking schemes are applied to bifacial panel arrays in two different PV orientations, i.e., East/West vs. North/South faced. By modeling the temporal variations of drop shadows on crops and the known requirements of photosynthetically active radiation (PAR) by the crop, we propose customized solar tracking schemes that vary between standard sun tracking and reverse sun tracking during the day according to the crop requirement. During the early daytime after sunrise and closer to the sunset, PAR is lower than the saturated PAR for the plants. Closer to noon, available PAR can exceed the crop needs. An optimal algorithm ensures that the PAR available to the crops remains closer to its required PAR so that the excess sunlight could be harvested by the PV arrays. The seasonal variation in customized tracking schemes is explored for the two PV orientations.