| 20110142625 | WATER TURBINE - A turbine for use in extracting energy from within a water flow comprises: an array of turbine blades formed and arranged for rotation, in use, about an axis substantially normal to the direction of water flow; wherein at least one turbine blade of the array is formed to be adjustable, in use, from a first, driving, configuration when moving with the direction of water flow, to a second, return, configuration when moving against the direction of water flow, and wherein the surface area of the turbine blade presented to the direction of water flow is reduced when in the return configuration. | 06-16-2011 |
