The concrete blocks are slowly hoisted upwards by motors powered with electricity from the Swiss power grid. As each block descends, the motors that lift the blocks start spinning in reverse, generating electricity that courses through the thick cables running down the side of the crane and onto the power grid. In the 30 seconds during which the blocks are descending, each one generates about one megawatt of electricity: enough to power roughly 1,000 homes.
Good idea, but I don’t believe that this system can store more energy than for a few houses. Can be a good system for a house near by a lake. For hydraulic store systems the use great lakes or very huge deposits… But yes, can be another auxiliary system in certain cases