The potential energy of the water located at a high place is converted into the kinetic energy of the generator turbine; by using the electromagnetic phenomenon within the generator, the electricity can be earned.
For waterpower generation, in order to increase the volume of generation, bigger potential energy is needed; therefore, areas with larger differences in elevations are more advantageous.
Canal system power station, which uses the natural difference in elevation and natural flux, is highly influenced by the topography, season, and precipitation; thus, in order to maintain a stable amount of generation and to heighten the difference of elevation, usually people use dam type generation.
In Korea, pumped-storage generation is used since in the summer there is a large amount of precipitation but during other seasons, the water is scarce.
This method uses remaining electricity at night, when there is less electricity consumption, to pump up the water to the upstream of the dam and then use the water again to generate power during the day.