Abstract: A toroidal vertical axis wind turbine apparatus (10) has a shaft (14) vertically mounted in a support (12) providing for rotation of the vertically mounted shaft (14) about its longitudinal axis, and a plurality of vertically oriented elongate turbine blades (16), each vertically oriented elongate turbine blade (16) having a length and a width, and a length-wise warp which extends along at least a substantial part of the length of the turbine blade (16), wherein each vertically oriented elongate turbine blade (16) is mounted upon the vertically mounted shaft (14) by support arms (18) such that the vertically oriented elongate turbine blades (16) are mutually spaced and outwardly spaced from the vertically mounted shaft (14) such that when contacted by wind, the plurality of vertically oriented elongate turbine blades (16) move around a toroidal path and cause axial rotation of the vertically mounted shaft.

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: 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.

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 turbine (1) with one or more stages. Each turbine stage has three longitudinally extending blades (5) each of which increases in axial cross-sectional width along the axis (2). The blades (5) are shaped to divert fluid flow and generate a rotation inducing torque. The fluid can be either wind or flowing water. The turbine (1) has a small footprint (surface area) and is normally used to generate electricity. Each blade (5) preferably has a vortex inducing edge strip (7).