The diagram below shows how electricity is generated in a hydroelectric power station Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

This

diagram illustrates the different stages of generating electricity by a hydroelectric power station. Looking from an

overall

perspective, it is readily apparent that the station works in a cyclical pattern on days and nights.

While

with the help of

water

flow it produces electricity during days, it pumps back the

water

at night. The process begins with the dam, which has a lot of

water

in its high-level

reservoir

. By opening the dam, the

water

flows into a generator and drives the station's

turbines

. By the rotation of the

turbines

, the generator works and produces electricity, which goes directly to the national grid with the help of power lines that are incorporated into the generator.

Additionally

, the

water

flow that passes through the

turbines

will go into a low-level

reservoir

. When the whole process is finished, at night, the

turbines

are rotated in reverse to extract the

water

from the low-level

reservoir

and pump it to the dam. The whole

water

flows in the high-level

reservoir

to save for the days.