Abstract: A vertical axis wind turbine (1) comprises three vertically extending sails (8) where each sail (8) comprises a strip (80) of substantially constant width. The opposite ends of each sail (8) are longitudinally twisted to have a pitch angle of approximately 90 degrees. The turbine (1) further comprises a vertically extending central core (7) and a vertically extending opening (9) between each sail (9) and the core (7). Also disclosed is an improvement in a vertical axis wind turbine (91) having at least one main blade (94) each of which has a longitudinal extent and a longitudinally extending radially outermost edge (924). The improvement comprises a longitudinally extending auxiliary blade (944) spaced from the main blade (94) to define a venturi inducing gap (99) between the main blade (94) and the auxiliary blade (944) whereby the turbine (91) has a zone of influence which extends radially beyond the maximum radial extent of the blades.
Abstract: A vertical axis wind turbine has a plurality of main blades each of which is relatively thin. The blades each have a thickened portion extending along the trailing edge of each blade. Furthermore, each blade is fabricated in at least two sub-sections, wherein at least one strut extends between a central support column and a junction where the blade sub-sections abut.
Abstract: The present disclosure provides a blade for a wind turbine. The wind turbine has an axis about which in use the blade rotates. The blade is arranged for orientation along the axis and has a predetermined twisted shape. The blade has a first and an opposite second side portion. The first and second side portions have edges and are coupled together at the edges. The first and second side portions are shaped such that a blade body is formed that is shaped such that maintaining the predetermined twisted shape of the blade is facilitated.
Abstract: A blade assembly is for a wind turbine, such as a vertical axis wind turbine. The blade assembly includes 3 or more blades and has an axis of rotation about which in use the blades rotate. In one variation the blades are elongated and have first and second ends and are twisted between their ends. The blades are positioned along the axis of rotation in a manner such that the first (bottom) end of each blade has a portion that has substantially the same angular orientation as a portion of the second (top) end of an adjacent blade. Alternatively or additionally the blades are arranged for orientation along the axis of rotation and are twisted about an axis of twist. The axis of twist substantially coincides with the axis of rotation of the wind turbine.
Abstract: A vertical axis wind turbine (1) has a plurality of main blades (7, 8, 9) each of which is relatively thin. The blades (7, 8, 9) each have a thickened portion (28) extending along the trailing edge (18) of each blade (7, 8, 9). Furthermore, the or each blade (7, 8, 9) is fabricated in at least two sub-sections, (801-806) wherein at least one strut (50-52) extends between a central support column (13) and a junction where the blade sub-sections (801-806) abut.