Applicability of photovoltaic panel rainwater harvesting system in improving water-energy-food nexus performance in semi-arid areas

Growing food demand challenges the expansion of agriculture, while water and energy shortages have seriously jeopardized agricultural sustainability. Therefore, the water-energy-food (WEF) nexus must be integrated into sustainable agriculture management. However, despite the increasing sophistication of models for WEF optimization, more studies have considered only how to reduce resource consumption and less on how to increase resource supply. This paper outlines an agricultural WEF optimization model based on photovoltaic panel rainwater harvesting (PVRH). The model innovatively incorporates the PVRH system into the agricultural WEF nexus, providing a decision-making framework that exploits and conserves resources in parallel, while contributing to economic benefits. The model was applied in a rural case study in a semi-arid region of China. The results highlight the significant potential of the PVRH system to exploit water and energy, and the increased resources are allocated to irrigated alfalfa and vegetables, which would significantly increase revenue. However, the model does not recommend large-scale vegetable cultivation, which would increase water and energy consumption and reduce the WEF indicator values indicating agricultural sustainability. The final scheme will build a 98.92MWp PV power station, develop 1.31 × 10⁸ kW·h of electricity and 1.97 × 10⁷ m³ of rainwater into agricultural production. And through cropping restructuring, it will increase 23.61 % of economic revenue and save 57.74 % of water and 3.24 % of energy. In general, the model framework is transferable and applicable to similar agricultural areas under semi-arid climatic conditions.