Israel’s BaroMar has developed an underwater solution for storing wind and solar power in the form of compressed air at depths of 200 – 700 meters. It claims to be the most sustainable energy storage solution, with a neutral carbon footprint, no hazardous materials, and minimal impact on surroundings.
https://www.timesofisrael.com/israels-economy-is-setting-sail-into-the-deep-blue-tech-sea/