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.
That’s like looking at solar panels and saying you couldn’t power more than a few streetlights from it - it’s about scale.
For storing with this enough energy for a village, with the hidraulic system they need a big lake, and with this system a grlobe of 1 km or hundreds of them (???). Yes, it’s a question of scale, but due to the limitations of a system.