Hydroelectric

Hydroelectric is a form of renewable energy that is not really growing in popularity. Hydro has been an established form of energy that is proven to work at a reasonably high production rate. Hydro power has been used since ancient times to grind flour and perform other tasks. In the mid-1770s, a French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical- and horizontal-axis hydraulic machines. By the late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand for the Industrial Revolution would drive development as well.. The major down fall for using hydro opposed to other forms of energy is that it requires a large body of water or a moving water source. The danger or hazard of hydro power exists if the dam were to give way. Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator.

http://en.wikipedia.org/wiki/Hydroelectricity