The diagram illustrates how electricity is produced in a hydroelectric power station using a system of reservoirs, turbines and a generator.
Overall, the process operates in two contrasting modes: during the day, water flows downhill to generate power, while at night the flow is reversed to store water for future use.
In daytime, river water is stored behind a dam in a high-level reservoir. When the intake gate is opened, water travels through a conduit towards the power station. As it descends, it drives reversible turbines, which in turn activate a generator. The electricity produced is transmitted via power lines to the national grid. After passing through the turbines, the water is discharged into a low-level reservoir.
At night, when electricity demand is lower, the system functions in reverse. The intake from the upper reservoir is closed, and the turbines operate as pumps. Water from the lower reservoir is forced back uphill through the same tunnel and returned to the high-level reservoir, replenishing its supply.
Thus, the station not only generates electricity efficiently during peak hours but also conserves energy by recycling water, enabling continuous and sustainable operation.
