Pumped storage underwater.

[Art Hunter]

https://www.iee.fraunhofer.de/en/presse-infothek/press-media/2024/fraunhofer-iee-and-partners-test-spherical-energy-storage-on-the.html 

This is worth monitoring. 

Art Hunter- Canadian Association for the Club of Rome (canadiancor.com)

What we do  (436) CACOR Splash v5 - YouTube

YouTube postings CACOR YouTube - Canadian Association for the Club of Rome (canadiancor.com)