The picture delineates the process of electricity generation in a hydroelectric power station.
Overall, this cyclic, man-made procedure involves flowing water into the station during the day and pumping it to the high-level reservoir at night.
Firstly, the water of the river is kept behind a dam at an elevation. During the day, the intake at the bottom of the dam is open, allowing the flow of water to the power station in order to generate electricity. In the power plant, the entered water causes reversible turbines to revolve, activating the generator to produce electricity. The generated power is then conveyed to power lines before transferring to the national grid for consumer distribution, while the remaining water enters a low-level reservoir.
At night, the water in the low-level reservoir is transported to the high-level reservoir through turbines which pump the water. As a result, it flows in the reverse direction to reach the high-level reservoir when the intake is closed.