The evolution of virtual water flows in China's electricity transmission network and its driving forces

Abstract

Long-distance electricity transmissions could transfer water stress associated with electric power generation from the consumption side to the production side. In China, the rapidly growing scale of west-to-east electricity transmission is contributing to rising water stress in the arid northwestern regions. This study investigates the historical evolution and driving forces of virtual water network embodied in inter-provincial electricity transmissions in China during the past decade (2006–2016), measured by both volumetric and stress-weighted water consumption. Results show that electricity production hubs and load centers increasingly diverged in China. Driven by both growing electricity demand in eastern regions and an increasing share of imported electricity, stress-weighted virtual water export from the water-deficient northwestern provinces increased by 120% during the study period. Water efficiency improvements in thermoelectric power generation have offset 35% of the potential growth in total volumetric virtual water transfers, and more than 50% for stress-weighted virtual water transfers. However, the effect of water efficiency improvements has diminished since 2012. Considering China’s ambitious plan to boost west-to-east electricity transmissions in the future, increasing the penetration of wind and solar photovoltaic power in electricity mix in northwestern regions should play a more significant role in relieving water stress in major electricity-exporting provinces.