Towards sustainable Agri-Photovoltaics through system design and viability in Semi-Arid conditions

Abstract

Agri Photovoltaic (APV) systems are a key technology offering a coupled solution for both food and energy, which reduces the land requirement while meeting the sustainable development goals. This work presents a design and performance analysis of various APV systems by modelling tilted mono-facial, (tilted and vertical) bifacial, and the single-axis east–west tracking (SAT) photovoltaic (PV) system. A 1.0 MW system has been considered under local meteorological conditions across multiple seasons for semi-arid climate of Lahore, Pakistan. The vertical bifacial (VB) system produces more electricity in the morning and late afternoon, along with its feature of covering minimum space to provide enough clearance for agricultural machinery. The SAT and tilted systems produced peak output of 780 kWh/m² and 772 kWh/m² in summer, while in winter their outputs drop to 587 kWh/m² and 542 kWh/m², respectively, showing a 19 % seasonal variation in energy generation. The SAT system produces maximum of 134.2 kWh monthly, which is 27.80 % more than that of the VB system, and 21.44 % more than that of the tilted bifacial system. The comparison of tilted mono-facial and bifacial systems result in a bifaciality gain of 8.3 % encouraging the applicability of bifacial technology despite its higher cost compared to mono-facial panels. Moreover, the Ohmic loss is found to be minimum (176 kWh in June) for VB system, while the SAT and mono-facial systems undergoes annual losses up to 3000 kWh under high-power conditions. The suitability of growing crops is validated via the high average Photosynthetically Active Radiation (PAR) value of 450 µmol/m²/S/Nm throughout 2023, it suffices the lettuce (162–185 µmol/m²/s) and tomatoes (231–347 µmol/m²/s) crops. Meanwhile, the APV system implementation has been affirmed to be economically viable based on the comparison of levelized cost of electricity (LCOE) with energy tariff indices of Lahore. In the light of all favored inferences, this work not only proves Lahore and the areas with similar environmental attributes suitable for deployment of APV but also serves as gateway for APV implementation. This study uniquely integrates energy output, LCOE, and crop-specific PAR analysis to evaluate APV feasibility considering its benefits in Lahore while offering a replicable model for similar semi-arid regions.