Photovoltaic deployment on suitable marginal land in China enables energy and sustainability co-benefits

Abstract The global expansion of photovoltaic systems for decarbonization increasingly occupies land resources and triggers ecological and agricultural trade-offs. Here we propose a marginal-land-based solution to ease these conflicts by integrating multi-criteria suitability constraints with a spatial non-dominated sorting algorithm to prioritize the use of suitable marginal land. We identify about 1.58 million square kilometers of marginal land suitable for photovoltaic development, including 0.40 million square kilometers ranked as top priority. Using only 0.3–0.9% of this suitable area could satisfy China’s projected photovoltaic installation demand for 2050. Depending on energy development pathways, following this solution could avoid the conversion of 1377–3765 square kilometers of cropland, 1549–4235 square kilometers of grassland, and 287–784 square kilometers of woodland. This would safeguard 429–1174 kilotons of annual grain production and prevent degradation of 1096–2998 square kilometers of forest-grassland ecosystems. These findings highlight the socio-ecological advantages and substantial energy potential of prioritizing marginal land for renewable energy expansion.