Design and Efficiency Testing of a Cross-Flow Turbine

An inexpensive American-made cross-flow turbine was designed, manufactured, and installed at a remote run-of-river site in Northern California. The 400 kW unit includes an innovative automatic flow control sliding device which allows infinite adjustment of flow to the runner, needed to optimize power on flashy streams. A draft tube provides 12 feet of suction head, needed to elevate the turbine above the flood plain. The efficiency of the turbine was measured using the dye dilution method to determine flow and a torque cell coupled between the turbine and generator to directly measure power output. This paper discusses the design specifications and efficiency testing results for the turbine.