Vertical axis wind turbine

A vertical axis wind turbine, comprising:

• at least one upper bearing;
• at least one lower bearing;
• a rotor blade assembly rotatably coupled at an upper end portion to the at least one upper bearing and at a lower end portion to the at least one lower bearing to rotate about a vertical rotational axis;
• and
• a support structure configured to impart a lifting force to the rotor blade assembly such that the weight of the rotor blade assembly is at least partially borne by the support structure.

A vertical axis wind turbine, comprising:

• at least one upper bearing situated on a vertical rotation axis;
• at least one lower bearing spaced from the upper bearing along the vertical rotation axis;
• an upper shaft extending through the upper bearing;
• a lower shaft extending along the vertical rotation axis through the at least one lower bearing, the lower shaft being separate and spaced along the vertical rotation axis from the upper shaft;
• a rotor blade assembly comprising a plurality of turbine rotor blades, the rotor blade assembly having an upper end portion that is coupled to the upper shaft, the rotor blade assembly having a lower end portion that is coupled to the lower shaft such that the rotor blade assembly can rotate about the vertical rotation axis;
• a plurality of supports angularly spaced around the vertical rotation axis;
• and
• a plurality of guy-lines, each having a first end anchored to the ground or a base, each guy-line being having a second end coupled to the upper shaft and supported by a respective support at a location intermediate its first and second ends, wherein the location at which each guy-line is supported by a support is at an elevation higher than the location at which its second end is connected to the upper shaft.

A method, comprising:

• tensioning a plurality of guy-lines such that the plurality of guy-lines collectively impart a lifting force on a rotor blade assembly of a vertical axis wind turbine such that the weight of the rotor blade assembly is at least partially borne by a support structure comprising the plurality of guy-lines and a plurality of supports;
• wherein the rotor blade assembly comprises an upper bearing assembly, each guy-line having a first end connected to the upper bearing assembly, each guy-line having a second end anchored to the ground or a base on which the vertical axis wind turbine is located;
• and
• wherein each guy-line is supported by a respective support at a higher elevation than a location at which the guy-line is connected to the upper bearing assembly.