Floating foundation for an offshore wind turbine, a system for extracting energy from wind, and a method of installing a wind turbine

A floating foundation for an offshore wind turbine, the floating foundation comprising

• a center pipe,
• a buoyancy section,
• a weight section, and
• a plurality of tensioned wire ropes,
• wherein the buoyancy section is fixed to an upper end portion of the center pipe for providing buoyancy to the floating foundation to keep the floating foundation floating in a body of water, and the buoyancy section is configured to float at a surface of the body of water such that an above-water portion of the floating foundation is above the surface,
• the weight section is fixed to an opposite, lower end portion of the center pipe for providing stability to the floating foundation, and
• the plurality of tensioned wire ropes extends between and are connected to the buoyancy section and the weight section for adding bend portioning strength to the floating foundation.

A system for extracting energy from wind, the system comprising

• a wind turbine and
• a floating foundation comprising
• a center pipe,
• a buoyancy section,
• a weight section, and
• a plurality of tensioned wire ropes,
• wherein the buoyancy section is fixed to an upper end portion of the center pipe for providing buoyancy to the floating foundation to keep the floating foundation floating in a body of water, and the buoyancy section is configured to float at a surface of the body of water such that an above-water portion of the floating foundation is above the surface,
• the weight section is fixed to an opposite, lower end portion of the center pipe for providing stability to the floating foundation, and
• the plurality of tensioned wire ropes extends between and are connected to the buoyancy section and the weight section for adding bend portioning strength to the floating foundation.

A method of installing a wind turbine, the method comprising:

• providing a floating foundation comprising a center pipe, a buoyancy section, a weight section, and a plurality of tensioned wire ropes, wherein the buoyancy section is fixed to an upper end portion of the center pipe for providing buoyancy to the floating foundation to keep the floating foundation floating in a body of water, and the buoyancy section is configured to float at a surface of the body of water such that an above-water portion of the floating foundation is above the surface, the weight section is fixed to an opposite, lower end portion of the center pipe for providing stability to the floating foundation, and the plurality of tensioned wire ropes extends between and are connected to the buoyancy section and the weight section for adding bend portioning strength to the floating foundation;
• installing a mast onto the floating foundation, and connecting it to the center pipe;
• installing a nacelle on a upper portion of the mast;
• and
• mounting a plurality of rotor blades onto the nacelle.

A method of improving stability of a floating foundation for an offshore wind turbine, the method comprising:

• providing the floating foundation, wherein the floating foundation has a weight section, a platform for a wind turbine, and an active heave compensation system, the active heave compensation system comprising at least one wire rope, at least one sensor, at least one actuator, at least one hoisting means, and at least one control device, the active heave compensation system being arranged to alter a position of the weight section relative to the platform for the wind turbine, wherein the at least one hoisting means is connected to the at least one wire rope, and wherein the control device is connected to the at least one sensor for receiving data from the at least one sensor and connected to the at least one hoisting means to communicate a signal to operate the at least one hoisting means to let out or pull in a length of wire rope;
• and
• altering the position of the weight section by altering the tension of the at least one wire rope connected to the weight section by pulling in or letting out a length of the at least one wire rope by use of the at least one hoisting means, wherein the altering of the position of the weight section is performed automatically as a result of the control device processing data obtained by the at least one sensor and as a response sends a signal to operate the at least one hoisting means.