It is the energy that is stored as dynamic energy in a gravitational field by the accumulation of large amounts of water at an altitude difference from the continuation of the flow of free water, and is rendered as kinetic by water drop. The kinetic energy can then either be used locally (eg watermills), or converted into electricity or other, which store it, so that it can eventually be transported over long distances. In the earth's water cycle, energy comes mainly from the sun that evaporates, that is, it raises (in the atmosphere) large amounts of water. The energy in this cycle is harnessed by the use of hydroelectric projects (dams, dams, closed fall ducts, hydro turbines, generators, escape channels).
Energy from water drop: The operation of hydroelectric units is based on the movement of water due to the difference in manometer height between the inlet and outlet points. For this purpose a dam is constructed that holds the required amount of water in the reservoir created. During its passage through the fall pipe, a turbine is driven which starts the generator.
The amount of energy produced is determined by the volume of water flowing, the difference in manometer height between the free surface of the reservoir and the turbine, etc. Therefore, the electricity produced depends on the amount of water in the reservoir. Therefore, hydroelectric projects can only be constructed in areas with significant rainfall, rich springs and suitable geological configuration. Usually the energy ultimately produced is used only in addition to other conventional sources of energy, covering peak loads. In Greece hydroelectric power meets about 9% of our electricity needs.
Hydroelectric Projects: Hydroelectric projects are classified on a large and small scale. Small-scale hydroelectric projects differ significantly from large-scale hydroelectric projects in their environmental impacts.
