Minimizing movements of offshore wind turbines
Techniques are disclosed herein for minimizing movement of an offshore wind turbine. Using the technologies described, a wind turbine may be mounted on a marine platform that is constructed and deployed to reduce environmental loads (e.g., wind, waves, . . . ) on the platform in both shallow and deep water. In some configurations, a fully restrained platform (FRP) is configured to support a wind turbine. According to some examples, moorings are attached to the FRP and/or the structure of the wind turbine structure to reduce movement in six degrees of freedom.
1. A method to restrain motions of a platform that hosts a wind turbine structure or an offshore substation, comprising,
temporarily mounting one or more weights to a buoyant structure coupled to the platform during transportation of the platform, wherein the one or more weights lower a vertical center of gravity (VCG);
attaching moorings at one or more elevations of the platform; and
rotating individual moorings about a respective attachment at an angle to create a moment arm, wherein attaching the moorings and rotating the individual moorings restrain surge, sway, heave, roll, pitch, and yaw motions.
2. The method of claim 1 , further comprising clamping moorings at a half-length to clear the moorings from a seabed.
3. The method of claim 1 , wherein the one or more weights are temporarily mounted to the buoyant structure during installation of the platform.
4. The method of claim 1 , further comprising attaching a second end of the individual moorings to a corresponding anchor.
5. The method of claim 4 , wherein each of the corresponding anchors are attached to a seabed.
6. The method of claim 1 , wherein the wind turbine structure is mounted in a wet tow during at least a portion of the transportation of the platform.
7. The method of claim 1 , wherein temporarily mounting one or more weights further comprises temporarily mounting the one or more weights beneath a hull.
8. The method of claim 1 , wherein the wind turbine structure is mounted on the platform at quayside.
9. The method of claim 1 , wherein the one or more weights are gravity anchors associated with the moorings.
10. The method of claim 1 , further comprising installing the wind turbine structure and a rotary nacelle assembly on the platform prior to transportation of the platform.
11. A method to restrain motions of a platform that hosts a wind turbine structure or an offshore substation, comprising,
temporarily mounting one or more weights to a buoyant structure coupled to the platform during transportation of the platform, wherein the one or more weights lower a vertical center of gravity (VCG);
attaching moorings at one or more elevations of the platform; and
rotating individual moorings about a respective attachment at an angle to create a moment arm, wherein attaching the moorings and rotating the individual moorings restrain surge, sway, heave, roll, pitch, and yaw motions;
wherein the platform includes:
a buoyant structure coupled to the platform;
at least one of a wind turbine structure or an offshore substation;
one or more anchors attached to a seabed; and
one or more moorings.
12. The method of claim 11 , further comprising clamping moorings at a half-length to clear the moorings from a seabed.
13. The method of claim 11 , wherein the one or more weights are temporarily mounted to the buoyant structure during installation of the platform.
14. The method of claim 11 , further comprising attaching a second end of the individual moorings to one or more anchors.
15. The method of claim 14 , wherein the one or more anchors are attached to a seabed that is between a depth of about forty meters and two hundred meters under a surface of water.
16. The method of claim 14 , wherein the one or more anchors are attached to a seabed that is between a depth of about twenty meters and one hundred twenty meters under a surface of water.
17. A method to restrain motions of a platform that hosts a wind turbine structure or an offshore substation, comprising,
temporarily mounting one or more weights to a buoyant structure coupled to the platform during transportation of the platform, wherein the one or more weights lower a vertical center of gravity (VCG);
attaching moorings at one or more elevations of the platform; and
rotating individual moorings about a respective attachment at an angle to create a moment arm, wherein attaching the moorings and rotating the individual moorings restrain surge, sway, heave, roll, pitch, and yaw motions;
wherein the platform includes:
a monopile that includes a first end embedded into a seabed, the platform coupled to the structure;
at least one of a wind turbine structure or an offshore substation; and
a buoyant structure that is integrated into the monopile.
18. The method of claim 17 , further comprising clamping moorings at a half-length to clear the moorings from a seabed.
19. The method of claim 17 , wherein the buoyant structure is an air can.
20. The method of claim 17 , wherein the moorings are tubular, and include vortex induced vibration suppression hardware to mitigate vortex-induced vibration.