Explain how Pumped-storage hydropower (PSH) can store energy.

The system consists of 2 reservoirs at different elevations, where the water can flow between them but through a hydroelectric power station. The higher elevation reservoir releases its water at higher energy demand times, where it flows through turbines generating electricity. When the energy demands are low and the power stations are producing excess energy, a pump is turned on using this excess energy to move the water from the lower reservoir to the higher reservoir string this energy as gravitational energy for later use. This process converts gravitational potential energy to kinetic energy and then to electrical energy and then reverses this conversion process to store energy.