Grant: Alliance Grants

Advanced Compressed Air Energy Storage (ACAES) is an emission free, Long Duration Energy Storage (LDES) technology that stores energy in the form of compressed air. Hydrostor Inc. is building three 500 MW ACAES facilities, two located in California and the other in Australia. Each region is sunny, arid, and has very strict water use regulations that can be challenging for large scale industrial temperature regulation that is essential to ACAES processes. The proposed collaboration will design two water-smart solutions to increase the functionality and capture untapped efficiencies of Hydrostor ACAES operations. Hydrostor ACAES uses the weight of a large recycling water body to keep the air compressed while it is stored underground in a hard rock cavern. To reduce the temperature and evaporation of the massive water reservoir, and to increase ACAES operational capability, an innovative floating solar cover will be designed. Solar photovoltaic technology will deliver power that has potential to charge batteries, provide ancillary electricity services to the grid, and/or deliver operational cooling. To release the energy from storage, ACAES technology uses turbo-expanders. The rapid expansion of gases is well known to produce a cooling effect. This process-innate cooling capacity has not yet been utilized to improve operational efficiency. This is because gas temperature ranges are quite high, and the expansion cooling takes place at a different time than when needed. This project aims to capture this "coolth" through the use of phase change materials that will store the cooling capacity for when it is needed later in the process. ACAES is a reliable and very dynamic operation that demands very comprehensive technoeconomic models to credibly determine the potential effects of technical and market modifications. This project will develop nascent solutions to increase ACAES capability and profitability, and will also provide key advances in strategic new clean energy technologies.