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.