The Energy–Water–Land Nexus of Global Water-Surface Solar Photovoltaics

Photovoltaic (PV) power generation, as a low-cost and clean energy technology, has become one of the most sustainable renewable energy sources. Water-surface photovoltaic (WSPV) systems exhibit a unique synergy in clean energy generation, water evaporation reduction, and land use efficiency, making them highly valuable for achieving the United Nations Sustainable Development Goals (SGDs). Using global PV data, we quantify the energy–water–land nexus of WSPV systems through capacity estimation and a water evaporation model. In this nexus, energy refers to the electricity generated by WSPV systems on water surfaces; the water surface acts both as the installation platform and a water-saving feature by reducing evaporation. WSPV systems also replace traditional ground-based stations, conserving land by avoiding cultivated and ecologically sensitive areas. Results show significant growth in WSPV installations from 2019 to 2022, with total installed capacity increasing by 87.37%, from 19,685.34 MW in 2019 to 36,888.62 MW in 2022. During this period, water savings grew by 91.96%, from 90.27 million m³ to 173.29 million m³ per year. The land area saved by WSPV systems also increased, from 86.68 km² to 162.27 km². WSPV deployment presents significant opportunities to integrate renewable energy production with water and land conservation, supporting sustainable global development.