Improved Land Use Efficiency Through Spectral Beam Splitting in Agrivoltaic Farms

Abstract

Installing photovoltaic (PV) collectors above arable land (Agrivoltaics) can aid with the shortage of available land area for solar power generation and food production. Most open field agrivoltaics are based on opaque PV devices which absorb photosynthetically active radiation (PAR, 400-700 nm), reducing crop yield and increasing variability in light distribution across the field. This research evaluates the performance of spectral beam splitter integrated photovoltaic (BSIPV) modules using a PV performance model. A high percentage (66 %) of PAR incident on the spectral beam splitter is transmitted effectively to the plants, while the near infrared radiation (NIR, > 700 nm) is reflected to the adjacent bifacial opaque photovoltaic module to generate power. In the model, seven rows of modules were placed uniformly across the field at a height of four meters from the ground. Considering a cool season (November – March) in Yuma, Arizona, in a conventional opaque PV agrivoltaic farm received 43 % lower total daylight integral (TDLI) across the season in comparison to open field with a coefficient of variation (ratio of standard deviation to mean expressed in percentage) of 56 % in TDLI across the field. On the other hand, the BSIPV agrivoltaic farm limited the drop in TDLI to 7 % in comparison to open field and the coefficient of variation to 14 % across the field. Thus, BSIPV showed a 36 % improvement in TDLI relative to the conventional opaque PV agrivoltaic farm. The results of the current study justify further research on the proposed collector concept.