I believe that the problem with this is that it's very weak, ie you need to lift a large amount of weight to a great height to store much energy. More details:

I believe that the problem with this is that it's very weak, ie you need to lift a large amount of weight to a great height to store much energy. More details: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/ http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor...