HYBRID COMPRESSED AIR ENERGY STORAGE SYSTEM

A hybrid compressed air energy storage system is provided. A heat exchanger 114 extracts thermal energy from a compressed air to generate a cooled compressed air stored in an air storage reservoir 120, e.g., a cavern. A heat exchanger 124 transfers thermal energy generated by a carbon-neutral thermal energy source 130 to cooled compressed air conveyed from reservoir 120 to generate a heated compressed air. An expander 140 is solely responsive to the heated compressed air by heat exchanger 124 to produce power and generate an expanded air. Expander 140 being solely responsive to heated compressed air by heat exchanger 124 is effective to reduce a temperature of the expanded air by expander 140, and thus a transfer of thermal energy from an expanded exhaust gas received by a recuperator 146 (used to heat the expanded air by the first expander) is effective for reducing waste of thermal energy in exhaust gas cooled by recuperator 146.