Co-location of agriculture and solar energy from a global WEFE-Nexus perspective

Solar energy is projected to become the main player in the clean energy transition. This will inevitably lead to the construction of utility scale photovoltaic plants, which can generate local competitions for land, especially with agriculture, compounding with other pressures on the agricultural sector such as climate change and demographic increase. From a Water-Energy-Food-Environment Nexus perspective, the superposition of panels and croplands on the same land, often referred to as agrivoltaics, can transform this competition into a synergy, thanks to the mutual provision of benefits between plants and panels. Under which conditions these synergies occur has been extensively studied at the local scale, while large-scale studies bridging the gap between the global energy transition challenge and its local limitations are still an emerging line of research. Here we quantify the current competition between photovoltaic and agriculture by cross-referencing high-resolution global datasets, and we assess the impact of shading from panels on water-stressed rainfed agriculture globally. To do so, we force a spatially distributed crop specific agro-hydrological model with different levels of solar radiation attenuation, and assess changes in water stress and biomass production rates to derive the associated yield response. Finally, we combine these results with a multi-criteria filtering approach and tolerance thresholds on yield losses to identify global croplands convertible to agrivoltaics. We find that 13%-16% of the global ground-mounted photovoltaic plants can be directly associated with a loss in croplands, while for 22% to 35% of the global rainfed croplands agrivoltaics would provide negligible damages if not benefits. In particular in arid and hot climates, agrivoltaics can reduce water stress, improving water use efficiency and yields. While such a study cannot be used as a feasibility study for agrivoltaic plants locally, it helps identifying regions where agrivoltaics can be a promising solution worth further investigation. This study was carried out within the RETURN Extended Partnership and received funding from the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005)