Optimizing the Spectral Sharing in a Vertical Bifacial AgriVoltaics Farm

AgriVoltaics (AV) allows double usage of the land by yielding both food and energy. Such farms are more suitable for high population density locations like India. In this work, we study the impact of the vertical, bifacial AV farm on the rice (Oryza Sativa) yield in a hot, tropical climate prevailing in the south-eastern part of the India (Chennai, 13.0827° N, 80.2707° E). We compare two different bifacial silicon solar cell technologies: i) Passivated Emitter Rear Contact (PERC+), and ii) Silicon HeteroJunction (SHJ), using vertical configurations. We show that SHJ yields more energy than PERC for the considered location, mainly due to its high-temperature coefficient, high inherent bifaciality, spectral and temperature advantage of the vertical configuration. To maximize both the rice and energy yield with equal importance, we discuss two strategies: i) varying the pitch of the panels (2m and 4m) ii) optimizing the spectral sharing between the panels and plants by reflecting the Photosynthetically Active Radiation (PAR) incident over the panels (2m pitch). We found that increasing the pitch of the panels (4m pitch) could improve the rice yield but drastically reduces the energy yield (~ 57% compared to 2m pitch). Using simulation, we show that by reflecting the small portion of the spectrum (400 nm to 500 nm) incident on the PhotoVoltaics (PV) panels (additional advantage of vertical configuration), both the rice and energy yield could achieve a win-win situation (91% of rice yield compared to open farm and 91% of energy yield compared to 2m pitch PV farm). The disadvantage of SHJ in PV farm becomes advantageous in AV farm due to its low dependence on the reflected portion of the spectrum compared to PERC+ solar cell. This work will motivate developing low-cost technologies to achieve spectral sharing a viable option in the future.