pelton

Pelton refers to a high-efficiency impulse water turbine used for hydroelectric power generation, commonly called the Pelton wheel or Pelton turbine. It is optimized for high hydraulic head and low flow, and unlike reaction turbines, it extracts energy from the water primarily by momentum transfer in an impulse jet, rather than by pressure drops within the runner.

Design and operation: Water is directed through one or more high-pressure nozzles to form a fast jet that strikes spoon-shaped buckets arranged around the wheel’s rim. The buckets are designed with double-curved surfaces, sometimes split to divide the jet into two parts, maximizing momentum transfer and minimizing jet rebound. The jet’s velocity and direction impart torque to the runner as the water exits, typically almost tangentially. The runner is connected to a generator through a speed-regulating mechanism, and the flow to the nozzles is controlled to maintain stable operation.

History: The device is named for Lester Allan Pelton, who developed the wheel in the late 19th century and patented the concept in 1889. Pelton’s design addressed energy extraction from high-head facilities and helped spur the broader adoption of hydroelectric power in suitable sites.

Applications and performance: Pelton turbines are widely used in hydroelectric plants with high heads and moderate-to-low flows. They are valued for robustness and relatively simple maintenance. Modern Pelton units typically achieve high efficiencies, often in the 90% range, and are manufactured in many sizes to match site head, flow, and power requirements. They remain a common choice for new high-head installations and for repowering older plants.