Water Current Turbines for River Applications - Alaska Energy ...

WCT EvaluationNRCan-06-01071Gorlov Helical Turbine- GCK TECHNOLOGY, INC (USA)Technology: GCK is the licensee of the Gorlov Helical Turbine (GHT) patents and technology. TheGHT is a cross-axis turbine consisting of one or more long helical blades that run along an imaginarycylindrical surface of rotation like a screw thread. The helical airfoil blades provide a reaction thrustperpendicular to the leading edges of the blades that can pull them faster than the fluid flow itself. TheGHT allows a large mass of slow water to flow through, capturing its kinetic energy and utilizing a verysimple rotor. It can be assembled vertically, horizontally or in any other cross-axis combination using acommon shaft and generator for an array of multiple turbines. Generating capacity is proportional to thenumber of modules. In its vertical orientation the generator and gearing can easily be positioned abovewater. The standard unit is now 1 m in diameter by 2.5 m in length. It starts producing power atapproximately 0.60 m/s, according to studies done in 2004.Application: The turbine can be operated in tides, non-tidal rivers, or ocean currents. The horizontalarrangement lends itself well to shallower rivers, tailraces or discharge channels from industrial plants.Stage of Development: In 2004, Verdant Power, assisted by the Massachusetts TechnologyCollaborative which is part of the Massachusetts Renewable Energy Trust, collaborated with GCK andtested four 1m diameter GHT’s mounted on a barge in the Merrimack River of Massachusetts. Theproject summary and final report can be found at http://www.masstech.org/Project_lst_rslt.asp?ID=54on MTC’s website. Issues raised in the report include concerns about vibration.Verdant Power Canada ULC 25