Energy+storage+through+potential+energy

One way of making renewable energies more constant is to "store" the energy as potential energy then converting it back to electrical energy when needed. This can be achieved by water storage. Water can be sored at height (hence potential energy) by pumping it up to a high resevoir from a low resevoir. This potential energy can be converted back to electrical energy when needed by using the water (from the high resevoir) to power a turbine.