Introduction

The most commonly used method of production of electricity from hydro power is by dams, which are constructed across the large rivers.The cost of hydroelectricity is relatively low, making it a competitive source of renewable electricity. The hydro station consumes only water, unlike coal or gas plants.With a dam and reservoir it is also a flexible source of electricity since the amount produced by the station can be changed up or down very quickly to adapt to changing energy demands. Once a hydroelectric complex is constructed, the project produces no direct waste, and has a considerably lower output level of greenhouse gases than fossil fuel powered energy plants.