Offshore wind turbines and methods for deploying and installing same

A method for deploying and installing an offshore wind turbine, comprising:

• (a) transporting an offshore wind turbine to an offshore installation site, wherein the wind turbine includes:
• a ballast adjustable hull;
• a telescopic tower movably coupled to the hull and retracted into a receptacle of the hull, wherein the telescopic tower has a central axis and includes a first tubular, a second tubular movably disposed about the first tubular, and a third tubular movably disposed about the second tubular, wherein the first tubular, the second tubular, and the third tubular are nested and concentrically arranged;
• an elevator disposed about the telescopic tower and movably coupled to the hull;
• a nacelle coupled to the telescopic tower;
• and
• a rotor assembly coupled to the nacelle;
• wherein the elevator includes a catch member at an upper end of the elevator and extending radially inward from the elevator into an annulus radially positioned between the elevator and the telescopic tower;
• wherein each tubular of the telescopic tower includes a catch member disposed at an upper end of the tubular and extending radially outward from the tubular into the annulus radially positioned between the elevator and the telescopic tower;
• wherein the catch member of the elevator is configured to engage the catch member of each of the tubulars to sequentially raise the tubulars of the telescopic tower to erect the telescopic tower;
• (b) floating the wind turbine over a desired installation location after (a);
• (c) ballasting the hull to lower the wind turbine after (b);
• (d) coupling the hull to a sea floor after (c) to hold the wind turbine at the installation site;
• (e) erecting the telescopic tower after (d) by telescopically extending the telescopic tower from the receptacle of the hull by:
• (e1) engaging the catch member of the first tubular of the telescopic tower with the catch member of the elevator and raising the first tubular axially relative to the second tubular and the third tubular with the elevator;
• (e2) lowering the elevator relative to the first tubular, the second tubular, and the third tubular after (e1);
• (e3) fixedly securing the first tubular to the second tubular after (e2);
• (e4) engaging the catch member of the second tubular of the telescopic tower with the catch member of the elevator and raising the second tubular axially relative to the first tubular and the third tubular with the elevator after (e3);
• (e5) lowering the elevator relative to the first tubular, the second tubular, and the third tubular after (e4);
• and
• (e6) fixedly securing the second tubular to the third tubular after (e5).

A method for erecting a telescopic tower of an offshore wind turbine, wherein the telescopic tower has a central axis and includes a first tubular, a second tubular movably disposed about the first tubular, and a third tubular movably disposed about the second tubular, wherein the first tubular, the second tubular, and the third tubular are nested and concentrically arranged, the method comprising:

• (a) engaging a catch member of the first tubular of the telescopic tower with a catch member of an elevator disposed about the telescopic tower and raising the first tubular axially relative to the second tubular and the third tubular with the elevator;
• (b) axially extending the first tubular from the second tubular and the third tubular during (a);
• (c) locking an axial position of the first tubular relative to the second tubular after (b);
• (d) lowering the elevator relative to the first tubular, the second tubular, and the third tubular after (c) with the first tubular axially locked relative to the second tubular;
• (e) engaging a catch member of the second tubular of the telescopic tower with the catch member of the elevator and raising the second tubular and the first tubular with the elevator after (d) with the first tubular axially locked relative to the second tubular;
• (f) axially extending the second tubular from the third tubular during (e);
• (g) locking an axial position of the first tubular and the second tubular relative to the third tubular after (f);
• and
• (h) lowering the elevator relative to the first tubular, the second tubular, and the third tubular after (g) with the first tubular and the second tubular axially locked relative to the third tubular.