Abstract Water is not only the source of life, but also as a medium for human beings to provide extremely rich green energy. In this paper, several typical water-driven power generation technologies are introduced, including traditional hydroelectric power generation, tidal power generation, and power generation by ocean temperature difference. The principles of power generation by salt difference, as well as the newly emerging “hydrovoltaic” are also discussed in details. In a whole, the water power generation technologies are presented as far as possible in popular language.
