Pelton wheels are among the most efficient types of water wheels. It was invented by Lester Allan Pelton (1829-1908) in the 1870s, and is an impulse machine, meaning that it uses Newton's second law to extract energy from a jet of fluid. It should be noted that the original one piece cast impulse water turbine was invented by Samuel Knight in Sutter Creek, CA in the California Mother Lode Gold Mining Region. Pelton modified his design to create his more efficient design, after an accidental observation he made in 1864 while working as a millwright and carpenter in the gold mines in Yuba County, California.
For the next 15 years, Pelton worked to perfect his design and by 1879 had perfected and tested a prototype wheel that was granted its first patent in 1880. By 1890 Pelton Wheels were in operation in a variety of applications, generating thousands of horsepower, powering all kind of equipment.
The Pelton Wheel pictured above resides with us here, at the Gold Creek Salmon Bake. It is a rare alternating-bucket impulse turbine directly connected to a cross-compound air compressor. This photo is circa 1890. Pelton Wheels are still in use today in hydro-electric plants worldwide.