When it comes to climate change and how we can achieve a low-carbon world, the discussion cannot ignore long-duration energy storage (LDES). Hydrostor is an Advanced-compressed air energy storage company, taking a proven technology in the form of traditional compressed air storage, and enhancing it in two fundamental ways: resulting in an emission free and flexible long-duration energy storage solution that can located where the grid requires. A-CAES is being developed at GW scale globally and has a 50+ year lifetime, proven and established supply chain, and zero efficiency degradation. A-CAES is optimized for large scale applications (hundreds of MWs) to enable large scale impact.