Grey water footprint and interprovincial virtual grey water transfers for China's final electricity demands

With a Multi-Regional Input-Output analysis, this study for the first time quantifies China's final electricity demands' life-cycle impacts on water quality using the indicator Grey Water Footprint (GWF). China's Grey Water Footprint for Final Power Demands (GWFP)amounts to 37.54 billion m³ in 2010, which is the highest in the north, east and central regions. Regarding the upstream sectoral contributions on a national scale, Coal Mining and Dressing, whose GWF is decided mainly by Chemical Oxygen Demand (COD)and petroleum, and Agriculture sector, whose GWF is decided by total nitrogen discharged, contribute the largest shares of 32.40% and 23.24%, respectively. 22.28 billion m³ of GWFP is transferred across provincial boundaries as virtual grey water embodied in electricity transmissions and trades of the power sector's upstream supplies. Electric power demands in coastal provinces induce water pollution in inland provinces. For example, 1.38, 1.07 and 1.06 billion m³ of GWF in Shanxi, Inner Mongolia, and Henan, respectively, are generated to fulfill final power demands in Shandong, Jilin and Shandong. Findings in this study are significant in helping policymakers recognize and mitigate final power demands' life-cycle adverse impacts on water quality. Moreover, insights of the inter-provincial virtual grey water transfers induced by power demands enable further discussions on burden sharing and compensation in terms of power demand management and water pollution controls.