Vertical axis turbine

A vertical axis turbine, the vertical axis turbine comprising:

• a frame rotatable about a central axis;
• either (a) at least two masts each having at least one boom, the at least two masts coupled to the frame with at least one sail coupled to each of the at least two masts, the at least two masts generally diametrically opposing each other across the central axis and substantially perpendicular to the frame, or (b) at least two blades rotatably coupled to the frame and being substantially perpendicular to the frame, the at least two blades generally diametrically opposing each other across the central axis;
• at least two retaining members being attached to the frame, each of the at least two retaining members defining an opening and corresponding to each of the at least two masts or of the at least two blades;
• and
• a non-compressible and rope-like cord having a first end coupled to the boom of one of the at least two masts and a second end coupled to the boom of the other of the at least two masts or having the first end of the cord coupled to one blade of the at least two blades and the second end coupled to the other blade of the at least two blades, the cord extending within the opening of the corresponding retaining members, wherein the cord is configured to regulate the position of the sail or blade.