High pressure water energy storage coming to San Antonio

https://cleantechnica.com/2022/03/08/high-pressure-water-energy-storage-coming-to-san-antonio/

"initial 1-megawatt, 10-hour storage facility... The rock acts like a natural spring to hold the water under pressure. When called upon to supply electricity, the pressurized water is released to power a hydroelectric turbine that generates emission free electricity. The entire process is closed loop to conserve water resources. CPS Energy will have the option to expand the project to provide 15 MW as the project matures"