Column-stabilized offshore platform with water-entrapment plates and asymmetric mooring system for support of offshore wind turbines

A floating platform comprising:

• a) at least three stabilizing columns, each column having an upper and a lower end, and an internal volume for containing a ballast;
• b) main beams interconnecting the at least three stabilizing columns;
• c) water-entrapment plates, each of the plates is attached to the lower end of one of the stabilizing columns;
• and
• d) a ballast control system that moves the ballast between the internal volumes of the at least three stabilizing columns to adjust a vertical alignment of the at least three stabilizing columns;
• wherein one of the columns supports more weight than the other columns, and
• wherein the main beams comprise first, second, third, fourth, fifth, and sixth main beams,
• the first main beam and the second main beam connect the one of the columns that supports more weight than the other columns and a first other column,
• the third main beam and the fourth main beam connect the one of the columns and a second other column, and
• the fifth main beam and the sixth main beam connect the first other column and the second other column.

A method of deploying a semi-submersible platform comprising:

• assembling at quayside the semi-submersible platform having a plurality of columns each containing ballast mechanisms;
• installing at quayside a tower assembly that includes a turbine rotor coupled to an electrical generator, on the semi-submersible platform;
• removing a ballast from the columns;
• moving the semi-submersible platform from shallow water at quayside into deep water more than 100 feet in depth;
• partially filling the columns with a ballast to stabilize when the semi-submersible platform is in the deep water;
• mooring the semi-submersible platform;
• detecting a floating angle of the semi-submersible platform that is outside a predetermined acceptable range;
• and
• operating the ballast mechanisms to correct the floating angle.

A method of operating a floating wind turbine platform comprising:

• a) providing the floating wind turbine platform apparatus having at least three stabilizing columns, each column having an upper and a lower end, and an internal volume for containing a ballast, a tower coupled to the floating wind turbine platform, a turbine rotor mounted on an upper portion of the tower, the turbine rotor coupled to an electrical generator, main beams interconnecting the at least three stabilizing columns, water-entrapment plates attached to the lower ends of the stabilizing columns and a ballast control system that includes a vertical alignment sensor and one or more pumps for moving the ballast between the internal volumes of the at least three stabilizing columns;
• b) rotating the turbine rotor;
• c) rotating the generator to produce electricity;
• d) detecting a list angle of the floating wind turbine platform that is outside a predetermined acceptable range;
• e) actuating one or more pumps to move the ballast between the stabilizing columns;
• f) detecting the list angle of the floating wind turbine platform that is within the predetermined acceptable range;
• g) stopping the one or more pumps to stop the movement of the ballast between the stabilizing columns.