The Turgo turbine is an impulse water turbine designed for medium head applications. Operational Turgo turbines achieve efficiencies of about 87%. In factory and lab tests Turgo turbines perform with efficiencies of up to 90%. It works with net heads between 15 and 300 m.[1]
Designed in 1919 by Gilkes[2] as a modification of the Pelton wheel, the Turgo has some advantages over Francis and Pelton designs for certain applications.
First, the runner is less expensive to make than a Pelton wheel. Second, it doesn't need an airtight housing like the Francis. Third, it has higher specific speed and can handle a greater flow than the same diameter Pelton wheel, leading to reduced generator and installation cost.
Turgos operate in a head range where the Francis and Pelton overlap. While many large Turgo installations exist, they are also popular for small hydro where low cost is very important.
Like all turbines with nozzles, blockage by debris must be prevented for effective operation.