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.

The picture illustrates the process of generating electricity from a hydroelectric

power

station. In general, two different sources of reservoirs supply

water

to the generator at the

power

station, resulting in electricity distributed to the national grid. Here is a

further

explanation.

To begin

with, from the left side,

water

from a river comes to a high-level reservoir with a dam

that is

open during the day and closed at night. From

this

site, the

water

flows to generate electricity and comes to the powerhouse, where the generator is turned by it, and

power

lines are distributed to the national grid.

This

system process is

also

implemented at a low-level reservoir that we can look at from the right side of the picture. The difference between both is just the

water

source. On the other side, reversible turbines in the

power

station operate the generator during the day only,

while

at night it pumps

water

from the low level of a reservoir into the high level.