look into energy stored on energy invested https://en.wikipedia.org/wiki/Energy_return_on_investment#ESOEI https://en.wikipedia.org/wiki/Energy_return_on_inves

look into energy stored on energy invested https://en.wikipedia.org/wiki/Energy_return_on_investment#ESOEI https://en.wikipedia.org/wiki/Energy_return_on_investment#ES... according to the wiki, pumped hydroelectric storage has a ratio of 704 where as compressed air energy storage has a ratio of 792.