The presented graph illustrates the process in which electricity is produced by a hydroelectric power station.
Overall, the process of generating electricity involves four key stages, beginning with intaking water from reservior and ending at distributing the generated power through the national grid.
At the starting point, there is a huge high-level reservior located in the back of a dam, collecting water which comes from the river. The gates of the dam are opened during days, flowing the water towards turbines, and closed during nights, pumping water and recollecting in the reservior. During the days, when the flow of water is towards turbines, it flows to a low-level resevior by which the generator located in the power station becomes active and produces electricity. In contrast, at nights the low-level reserviorbecome empty and the reversed flow can generate more power by flowing through the reversible turbines. The generated power goes to national grid via power lines.