Pelton wheel
The pelton wheel is a kind of water turbine. It is used in power plants, to convert a water flow into a movement of a wheel (and then into energy). Lester Alan Pelton invented it in the 1870s. In a regular wheel for example of a mill, the energy is obtained from the weight of the water. A pelton wheel uses the impulse of the water to generate energy, not its weight.  Pelton wheels are used in power plants where there's a big difference in height, but where there is relatively little water. An example might be a dam or barrage in the mountains. One of the drawbacks of a pelton wheel is the relatively hight level of wear:  Unlike the Francis turbine, a pelton wheel cannot be used to pump water.