Economic and environmental feasibility of coupled wind power-subsurface compressed CO2 energy storage system in China: An LCA approach

Abstract

Energy storage is a crucial solution for addressing the uneven distribution of renewable energy sources, including wind, hydropower, and solar. A novel technology that combines energy storage with underground CO2 storage is introduced, building upon compressed CO2 energy storage (CCES), an advancement of compressed air energy storage systems. Through a case study and literature review, a life cycle assessment (LCA) is conducted to evaluate the economic and environmental performance of a wind power—CCES coupled system. The results indicate that the global warming potential (GWP) and acidification potential (AP) of the CCES system coupled with wind power are 19g CO2-eq/kWh and 0.13g SO2-eq/kWh, respectively, which are significantly lower than those of coal power and are lower than those of wind power alone. Currently, the power output of this energy storage system is limited. However, in an optimistic scenario, the cost to build and operate a wind power—CCES coupled system can be recovered within 16 years based on current electricity prices in China. Therefore, utilizing CO2 storage reservoirs to store excess electricity from wind power is a feasible approach in China's power system from both economic and environmental perspectives.