Turbine-integrated Isothermal Compressed Air Energy Storage for a Wind Farm

Abstract Because of the intermittency problem of wind power, co-located energy storage for wind farms is becoming more common, especially for grids with high shares of wind energy. Currently, most co-located wind farm energy storage is achieved with Lithium-Ion Batteries (LIB). LIB provides high round-trip efficiency but has high costs, which limit the average capacity duration to about 2 hours. The two primary energy storage technologies that offer lower cost for capacity are Pumped Hydro Storage and Compressed Air Energy Storage, but both are challenged by topographical and geographic limitations, which limit site opportunities. Herein, a new concept Turbine-integrated Isothermal Compressed Air Energy Storage (TICAES) is proposed, which allows much more site opportunities by using underground reservoir that are small enough (e.g., 40,000 m 3 ) to allow deployment in bedded salt formations, which are relatively common and often located at or near wind farms leverages. TICAES further leverages existing components in the nacelle (gearbox, generator, etc.) and employs a near-isothermal reciprocating compressor/expander for high efficiency. However, this new concept requires further validation of techno-economic feasibility and consideration of complex nacelle integration issues.