Abstract:
Compressed Air Energy Storage System or Other System with Cold Storage An energy storage apparatus comprises a compressor arrangement configured to compress air or other process gas and to supply the compressed air or other process gas to a compressed gas store; an expander arrangement configured to expand the air or other process gas from the compressed gas store; a first heat transfer device associated with the expander arrangement; a thermal store including a thermal storage medium; and a second heat transfer device associated with the compressor arrangement. The first heat transfer device is configured to transfer heat to the air or other process gas which has passed through the expander arrangement from the thermal storage medium, the transfer producing a reduction in the thermal energy of the thermal storage medium in order to store cold in the thermal store. The second heat transfer device is configured to transfer heat between the thermal storage medium and the air or other process gas before the air or other process gas is stored in the compressed gas store, the transfer producing an increase of the thermal energy of the thermal storage medium. The thermal store is configured to store cold such that the temperature of the thermal storage medium in use is below ambient temperature. The thermal transfer fluid and/or the thermal storage medium may be a phase change material.
Abstract:
A method of energy storage comprises receiving input energy (1) and using the input energy to compress (2) air or other process gas to produce a compressed process gas. The compressed process gas is stored (8). The compressed process gas is expanded (16) to generate output energy (17). Heat is transferred (5) from the process gas, before the process gas is stored (8) as a compressed process gas, to a hydrogen production process (10). The transferred heat is used in the hydrogen production process (10). The hydrogen may be stored (13) and subsequently used to heat to provide heat prior to, during, or after expanding (16) the compressed gas.