The given diagram depicts the process by which electricity is produced in a hydroelectric power station. Overall, the system involves three main stages, beginning with utilization of gravitational water flow between a high-level and low-level reservoir and ending with the distribution of electricity via a national grid.
During the day, accumulated water behind the dam flows from the high-level reservoir to some reversible turbines through a pipe. This happens because the dam’s intake opens during the day and allows the water to flow in order to generate electricity. When the flowing water reaches the turbines, it spins them. These turbines are connected to an electricity generator, which, when rotated by the turbines, produces electricity. The electricity generated by the generator is then transferred to the power grid by power lines for distribution and use.
After rotating the turbines, the water flows into a low-level reservoir. At night, the turbines work in a reversible direction, pumping water back into the high-level reservoir. The intake, which was open during the day, is closed at night, making it impossible for water to flow towards turbines. Pumped-back water is ready to generate electricity again during the next day.