Energy–water nexus of wind power generation systems

Abstract

Energy and water are two interwoven elements of power generation systems. Because wind power is regarded as a promising renewable energy, how to increase its production and reduce energy and water costs has attracted many attentions. However, there is a lack of comprehension of the energy–water nexus in wind power generation systems. In this study, we developed a new energy–water nexus analysis framework for wind power generation systems, which includes both element and pathway nexus analyses. In element nexus analysis, energy used for water extraction and wastewater treatment and water consumed for electricity generation were investigated. The mutual interactions and control situations within the wind power generation system were also examined in pathway nexus analysis based on Network Environ Analysis (NEA). Taking a typical wind power generation system in China as the case, the element nexus analysis results show that water consumptions per unit of wind power generation are much lower than those of the other power generation systems. Energy consumption of the water system in the wind power generation system is 3.395×107MJ, of which water extraction process constitutes 90.22%. In pathway nexus analysis, network utility analysis and network control analysis are performed to investigate the dominant sectors and pathways for energy–water circulation and the mutual relationships between pairwise components of the wind power generation system. The results of network utility analysis show that compartment of surface water and groundwater (WA) is beneficiary from waste treatment (WT), which implies that although extra energy is devoted to WT, the benefit of water recycling is larger than energy cost. The results of network control analysis indicate that on-grid power (PG) not only depends on direct wind resource input (WI) (with a dependence coefficient of 0.20), but also indirectly supported by major compartments of fossil fuel input (FU) (0.16), construction material input (CO) (0.14), and wind turbines manufactory (MA) (0.12). Compartments of WA and MA have large dependences on WT. Therefore, increasing wastewater and material treatment and recycling in the wind power generation system could reduce water and energy demand from the external environmental. Dissipation (DIS) mainly relies on FU (0.19), wind power generation (WP) (0.16) and CO (0.2), which should be the focus of dissipation reduction. The presented energy–water nexus analysis may shed light on synergistic management of wind power generation systems.