Co-benefits and trade-offs between future electricity generation and water use on a global scale

Abstract:

Water is essential to electricity generation. Power plant cooling water is responsible for 40-50% of total freshwater withdrawals in Europe (Rübbelke et al., 2011) and the United States (Kenny et al., 2009). In accordance with growing demands for electricity generation, water demands could be increased. There is concern that the water demands for electricity generation could compete with other major water users. Additionally, many countries are required reviewing energy policies to mitigate climate change. Thermal power replaced low carbon power like renewable energy, nuclear power, Carbon Capture and Storage as a mitigation technology. However, influences of such climate change mitigation technologies on water demands are still uncertain. In this study, we calculated freshwater demands for electricity generation by using the data set of future electricity generation in the twenty-first century which estimated by the Asia-Pacific Integrated Model, and assessed the overall effects of electricity generation on water demands under the Shared Socio-Economic Pathways and the Representative Concentration Pathways which were adopted by IPCC AR5. Water demands for electricity generation depends on cooling types, such as once-through cooling and recirculating cooling. We also took into account cooling system pathways. The result might be useful for deciding energy policies which aim for reduction of water demands, especially in regions experiencing water scarcity.