Water saving potential for large-scale photovoltaic power generation in China: Based on life cycle assessment

While large-scale photovoltaic is regarded as a water saving generation technology, it comes with direct water consumption and embodied indirect water consumption associated with the manufacture of system equipment and building materials during construction. However, few studies have quantified the water consumptive use for photovoltaic generation from a life cycle perspective. In this context, this paper carefully calculated the life cycle water consumption for large-scale photovoltaic power generation in China and identified the hot spots in its supply chain. The results show the life cycle water consumption per kW installed capacity of large-scale photovoltaic plants is 20,419 L. Photovoltaic panel production and the Balance of System together make up over 85% of the total. The application of recycling technologies to the photovoltaic system is promised to cut down the total water consumption by another 13%. Then the water consumption intensity of large-scale photovoltaic power generation in China is presented at the provincial resolution in the range of 0.45-1.52 L/ kWh, which is significantly lower than that of current power generation in China. In addition, considering the power generation structure in China in recent years, the water saving potential under the maximum photovoltaic scenario in China during the year 2015-2017 could reach 3.75%, 4.04%, and 4.27% of China's national water supply. Finally, the regional water stress index is also introduced to explore the influence of water consumption on locally available water resources. This study could enable policymakers to better relate the development of large-scale photovoltaics to water saving strategies.

Automated summary

This study calculates the life cycle water consumption for large-scale photovoltaic power generation in China and identifies the key areas in its supply chain. The results show that the production of photovoltaic panels and system balance account for over 85% of the total water consumption. By implementing recycling technologies, the total water consumption of photovoltaic systems can be reduced by 13%. The water consumption intensity of large-scale photovoltaic power generation in China is significantly lower than that of current power generation. Furthermore, under the maximum photovoltaic scenario, there is a potential for significant water savings in China.