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 figure depicts the process of electricity production in a hydroelectric power station. This linear process involves the generation of electricity from a river and the storage of water in a reservoir.
In general, the diagram is broadly separated into day and night stages. This process begins when the river water flows from the high-level reservoir into low-level reservoir and ends up with the transmission electricity to the nation grid.
In the day stage, river water channels into an upper level reservoir backed up by a dam. There is an intake area that the dam opens during the day and closes at night. Once the gate of dam opens, the water flows to power station to power electricity. Subsequently, the water is generated by power lines and then sent to national grid, while the excess water flows into low-level reservoir.
Following the first stage is the night stage when the excess water is pumped back to the initial reservoir by the reversible turbines. Next, the dam closes and the river water is stored until a new days starts and the cycle continues