An examination of how much water is needed for coal-fired power production water footsteps in gray and blue

Despite the fact that water scarcity is inextricably linked to coal-fired power production, water footprint studies are few. This research seeks to overcome this restriction by performing the first-ever water footprint analysis of coal-based power production in China to educate decision-makers on how to minimize freshwater use and wastewater outflow. In 2015, 1 kWh of energy generated 1.78 103 m3 of gray water footprint in China, which is 1.3 times more than the blue water footprint score of1.35 103 m3/kWh. Although the national total gray water footprint grew substantially from 2006 to 2015 as power producing capacity expanded, the water footprint of 1 kWh of energy supply reduced. The blue water footprint showed the opposite tendency. Gray water footprint was dominated by indirect processes, whereas direct freshwater use contributed 63.6 percent to blue water footprint. Transportation, direct freshwater use, direct air emissions, and coal washing may all be improved, resulting in significant environmental advantages. Phosphorus, mercury, hexavalent chromium, arsenic, COD, and BOD5 were also important components of the gray water footprint. According to the findings, combining rail and water transportation should be emphasized. The planned shift to a high coal washing rate and the construction of pithead power plants may help to alleviate environmental costs, but water supplies in coal-producing areas must be addressed.