Life cycle water consumption embodied in inter-provincial electricity transmission in China

Abstract

Potential conflict is increasing between rapid energy demand and poorly endowed water resources in China. From perspective of life cycle assessment, water footprints of five electricity types (sourced from thermal, hydro, nuclear, wind and solar power) were explored, evaluated and compared. It indicated that direct water consumption and water consumption of upstream stages are important for thermal and renewable electricity to reduce their water consumption in electricity generation. In the inter-provincial electricity transmission, virtual water totaled 2.99✕109(Gm3) in 2013, to which virtual waters via thermal, hydro-, nuclear, wind and solar power contributed 28.87%, 71.02%, 0.03%, 0.08% and 0.01%. The maximum virtual water flow is from Southern and Central China Grid (such as Sichuan and Hubei) to Eastern China Grid (such as Shanghai). However, when considering the Water Stress Index, the proportion of virtual scarce water in hydropower decreases to 52.1%, while that of thermal power generation reach 47.4%. The maximum virtual scarce water flow become the Northwest and Northeastern China Grid (such as Inner Mongolia) to Northern China Grid (such as Hebei). Foreseeable electricity transmission will be dominated by transferring from West to East, and the ongoing long-distance electricity transmission projects will enlarge the scale of virtual water outflows from western regions and potentially increase their water stress. It is necessary to improve effective of water resource management and policy making for hydropower in southwestern region and thermal power in northwestern region.