Thermodynamic and applicability analysis of a hybrid CAES system using abandoned coal mine in China

China's wind and solar (WS) energy grow rapidly but simultaneously cause high wind and solar resource abandonments. Large-scale energy storage facilities, such as compressed air energy storage plants (CAES) must be complimented to balance the intermittent of these powers. However, in China's wind-solar-rich places (Three North Region), there is no salt formations for CAES construction. Thus we propose a hybrid WS-CAES system using roadways of...