The Pelton wheel or Pelton Turbine is an impulse-type water turbine invented by American inventor Lester Allan Pelton in the 1870s. The Pelton wheel extracts energy from the impulse of moving water, as opposed to water's dead weight like the traditional overshot water wheel. Many earlier variations of impulse turbines existed, but they were less efficient than Pelton's design. Water leaving those wheels typically still had high speed, carrying away much of the dynamic energy brought to the wheels. Pelton's paddle geometry was designed so that when the rim ran at half the speed of the water jet, the water left the wheel with very little speed; thus his design extracted almost all of the water's impulse energy—which made for a very efficient turbine.
Old Pelton wheel from Walchensee Hydroelectric Power Station, Germany.
Assembly of a Pelton wheel at Walchensee Hydroelectric Power Station, Germany.
Bucket detail on a small turbine.
A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work.
The runner of the small water turbine
The construction of a Ganz water Turbo Generator in Budapest in 1886
Roman turbine mill at Chemtou, Tunisia. The tangential water inflow of the mill race made the submerged horizontal wheel in the shaft turn like a true turbine.
A Francis turbine runner, rated at nearly one million hp (750 MW), being installed at the Grand Coulee Dam, United States.
