[en] This study, for the first time, investigates the historical changes of the water use in China’s electric power sector on a regional level and quantifies the impacts of four factors that have influenced the remarkable changes: population, power production per capita, power plants’ type and their cooling technology choice. From 2000 to 2015, water withdrawal and consumption in China’s electric power sector, excluding hydropower, have increased from 40.75 and 1.25 billion m³, respectively, to 124.06 and 4.86 billion m³. As population growth in China has stabilized, population no longer provides an upward pressure on power production and the corresponding water use. On the contrary, power production per capita has played the most significant role contributing to 103.40 and 3.84 billion m³ of water withdrawal and consumption increases respectively, though the effect is now leveling off. The electric power sector’s water use would have been much greater had it not been for changes in plant type and cooling water technology. Energy transformation to low-carbon sources has mitigated water withdrawals and consumption by 14.46 and 0.43 billion m³ respectively during the study period. This beneficial reduction in water use is a co-benefit of a series of policies primarily aimed to reduce carbon emissions and other air pollutants. Changing cooling technologies has offset 14.07 and 0.10 billion m³ of water withdrawal and consumption increases nationally, but the effects varied by region. (letter)

[en] Highlights: • Both water depletion and pollution by coal-fired power generation are quantified. • Petroleum pollutant determines the life cycle grey water footprint. • Water pollution mostly occurs in the fuel supply sector. • The grey water footprint was reduced by 49% from 2002 to 2012. In the present study, both water depletion and degradation in the life cycle of power generation at coal-fired power plants in China are quantified using a mixed-unit input-output model. National life cycle Withdrawal, Blue and Grey water footprint (WF) of thermal power production in China are estimated to be 35.46, 2.14 and 17.67 m³ per MWh of electricity produced, respectively. Those three types of life cycle WFs experienced significant reductions from 2002 to 2012 due to improved technologies such as water saving and wastewater treatment. Although Chemical Oxygen Demand (COD) pollutant had the largest discharge amount in the life cycle process of electricity generation, petroleum pollutant that was mostly discharged from coal production determined the Grey WF because of its lower permissible concentration. The spatial distribution of scarce WFs, incorporating regional water stresses, is also studied at the provincial level to identify the impacts of thermal power generation on regional water scarcities. Scarce water consumption was concentrated in northern China while scarce water was predominantly withdrawn in eastern China.

[en] Highlights: • This study assesses the household consumption's GWF in China from 2002 to 2017. • Total nitrogen determines the grey water footprint (GWF) of household consumption. • The change of household consumption's GWF was greatly driven by increasing consumption expenditure. • The increasing GWF from the poor to the rich is retarded by the changing consumption pattern. Urbanization is accompanied by growing household consumption and changing consumption patterns, with both having impacts on the life-cycle water pollution generated. This study uses the indicator of grey water footprint (GWF) within an Input-Output framework to examine the decadal change from 2002 to 2017 of the life-cycle water pollution change for household consumption in China, where rapid urbanization has particularly posed looming environmental challenges. Against the background of enlarging inequality, the results also shed light on the impacts of households within different income groups. From 2002 to 2017, GWF required by urban household consumption has increased significantly from 1586 to 2195 km³ while that for rural households have decreased slightly from 1139 to 964 km³ during the same period. Total Nitrogen required the largest GWF throughout the whole period and throughout all different income groups. Food consumption dominated the GWF for household consumption. However, the share of GWF for food consumption decreases with income increases, from 83% for extremely poor rural households to 71% for very rich urban households in 2012. Urbanites on average require higher GWF for their consumption than their rural counterparts. An average person from the highest income rural households required 2033 m³ GWF for household consumption, which is higher than a person from a very poor urban household (1685 m³) but lower than that of a person from poor urban household (2149 m³). While household consumption volume increase has been the primary driver for GWF increase, pollution intensity reduction has offset such impacts. Household consumption pattern change's impacts differ by household income and by pollutant considered.

[en] Highlights: • China's current carbon targets do not affect the development of the North China Grid. • Water sector policies have much larger impacts on the North China Grid. • Capping water use increases carbon emissions from the North China Grid. • Imposing both water and carbon constraints can realize co-benefits but at higher costs. The North China Grid has the highest proportion of fossil fuel-based electricity generation in China and also suffers from severe water scarcity issues. This study uses a multi-objective optimization model to explore future configurations of generating and cooling technologies of the electric power sector in the North China Grid subject to constraints imposed by existing policies on water conservation and carbon reduction in 2030. Our findings highlight that the current carbon reduction commitments of China do not have significant impacts on the North China Grid's electric power sector development while policies in the water sector generate much larger impacts. Imposing water constraint according to the ‘Three Red Line’ Policy requires increasing utilization of wind power and air cooling systems, which simultaneously increases economic cost and carbon emissions compared to the business as usual scenario. Imposing enhanced carbon emission and water consumption constraints reap the co-benefits of carbon reduction and water conservation by increasing the proportion of solar PV generation to 8.21%, which increases the unit electricity cost from RMB 0.82 per kWh to RMB 1.37 per kWh. In 2030, electricity generation in the North China Grid generates 1599.88 to 1690.89 million tons (Mt) of carbon emissions under different scenarios whereas imposing water constraint reduces water consumption from 3.34 billion m³ to 1.94 billion m³.

[en] Highlights: • China’s thermoelectric power consumed 3.8 billion m³ of water in 2010. • China’s hydropower consumed 14.6 billion m³ of water in 2010. • 60.2% of the power sector’s water use was driven by industries’ power demands. • 47.5% of the power sector’s water use was virtually transferred across provinces. • Water-scarce inland provinces are exporting virtual water via their power sector. Water consumption in thermoelectric and hydropower plants in China increased from 1.6 and 6.1 billion m³, respectively, to 3.8 and 14.6 billion m³ from 2002 to 2010. Using the concept of virtual water, we attribute to different electricity users the total water consumption by the electric power sector. From 2002 to 2010, virtual water embodied in the final consumption of electricity (hereinafter referred to as VWEF) increased from 1.90 to 7.35 billion m³, whilst virtual water in electricity used by industries (hereinafter referred to as VWEI) increased from 5.82 to 11.13 billion m³. The inter-provincial virtual water trades as a result of spatial mismatch of electricity production and consumption are quantified. Nearly half (47.5% in 2010) of the physical water inputs into the power sector were virtually transferred across provincial boundaries in the form of virtual water embodied in the electricity produced, mainly from provinces in northeast, central and south China to those in east and north China. Until 2030, VWEF and VWEI are likely to increase from 5.27 and 14.89 billion m³ to 7.19 and 20.33 billion m³, respectively. Climate change mitigation and water conservation measures in the power sector may help to relieve the regional pressures on water resources imposed by the power sector.