Recent development: https://arstechnica.com/science/2017/03/german-institute-successfully-tests-underwater-energy-storage-sphere/ https://arstechnica.com/scienc

Recent development: https://arstechnica.com/science/2017/03/german-institute-successfully-tests-underwater-energy-storage-sphere/ https://arstechnica.com/science/2017/03/german-institute-suc...