Water–energy Nexus in China's Electric Power System

Abstract

The electric power system is water–intensive, which aggravates the water scarcity of China. Deeper understanding of the role of electric transmission systems coupling with virtual water flows is critical for sustainable development of China. In this study, the flux and direction of virtual water within power system were firstly analyzed. Water scarcity index (WSI) was also incorporated to evaluate the virtual scarce water flows. Then, we calculated the hybrid electricity flux by multiplying electricity flux with its proportion of total electricity consumption to elucidate the significance of flux on the node's electricity supply. Finally, we studied the virtual scarce water flow network and hybrid electricity flux network via throughflow analysis to shed light on the nexus within the power system. The results show that electricity inflows bring in 27.99 GL of virtual scarce water concurrent with 10.865 TW h of electricity, and 47.47 GL of virtual scarce water concurrent with 15.072 TW h of electricity into the north and central regions of China. It can be concluded that a large volume of virtual scarce water (16.3 GL) is transferred via the electric power system, mainly from inland areas to coastal areas, which is roughly the opposite of the distribution of China's water resources. By doing this, we aim to evaluate the energy–water nexus rate in the electricity power system to balance the tradeoff between electricity supply and the regional inequity of water resources.