The provided diagram illustrates the process of electricity generation in a hydroelectric power station.
The diagram depicts two distinct water flows during the day and at night: the daytime flow is from the high-level reservoir to the low-level reservoir, while the nighttime flow is in the opposite direction. The daytime operation involves the intake opening to allow water from the high-level reservoir to generate electricity through reversible turbines and a generator; the electricity produced is then transmitted to the national grid. Conversely, at night, water is pumped from the low-level reservoir to the high-level reservoir through the reversible turbines with the intake closed.
During the daytime, water from the high-level reservoir flows to the low-level reservoir, where it powers the reversible turbines to operate the generator, facilitating electricity production for the national grid.
Conversely, at night, the process reverses, with water being pumped from the low-level reservoir back to the high-level reservoir through the reversible turbines, showing a contrasting flow pattern to the daytime operation. Additionally, the intake is closed during the nighttime operation.