A Method for Installing an Offshore Wind Turbine and a Substructure for an Offshore Wind Turbine

Abstract

A method of installing an offshore wind turbine includes the step of raising a full-length tower for the offshore wind turbine by moving it longitudinally from a container in a substructure, the substructure being a support structure for the wind turbine, wherein the substructure is arranged with a container configured for housing a tower for the wind turbine substantially in its entirety.

Claims

1. A method of installing an offshore wind turbine, the method comprising the step of: raising a full-length tower for the offshore wind turbine by moving it longitudinally from a container in a substructure, the substructure being a support structure for the wind turbine.

2. The method according to claim 1, wherein the step of raising the tower is performed by use of a device for moving the tower longitudinally.

3. The method according to claim 1, wherein the tower is moved longitudinally by at least one of jacking, hoisting, pulling, driving, and pushing the tower upwards.

4. The method according to any claim 1, wherein the method comprises the step of installing a nacelle and one or more blades to the top of the tower, wherein the step of installing the nacelle and the one or more blades to is performed prior to fully raising the tower.

5. The method according to claim 4, wherein the method further comprises the step of bringing the tower into an intermediary position by moving it longitudinally from a lowermost position prior to the installation of one or more of the nacelle and a blade.

6. The method according to claim 1, wherein the method further comprises the step of locking the tower into a position by use of a locking mechanism, wherein said position may be a lowermost position, an uppermost position or an intermediary position, wherein the intermediary position is a position between the lowermost position and the uppermost position.

7. The method according to claim 1, wherein the substructure is a floating substructure.

8. The method according to claim 1, wherein the substructure comprises a substantially vertical longitudinal axis and when the method is performed when the substructure is upright, in its operational position.

9. The method according to claim 1, wherein the substructure is a spar buoy.

10. The method according to claim 1, wherein the substructure comprises a load-carrying device, and wherein the method comprises the step of lifting equipment by use of the load-carrying device from a vessel to the substructure.

11. The method according to claim 1, wherein the method comprises the step of upending the substructure prior to raising the tower.

12. The method according to claim 11, wherein the step of upending is comprises ballasting.

13. A substructure for an offshore wind turbine, wherein the substructure is arranged with a container configured for housing a tower for the wind turbine substantially in its entirety.

14. The substructure according to claim 13, wherein the substructure is a floating sub-structure.

15. The substructure according to claim 13, wherein the substructure comprises a substantially vertical longitudinal axis when the substructure is in its upright, operational position, and wherein the container: comprises a substantially cylinder-shaped; and comprises a longitudinal axis parallel and aligned with the longitudinal axis of the substructure.

16. The substructure according to claim 13, wherein the substructure is a spar buoy.

17. The substructure according to claim 13, wherein the substructure comprises a device for moving the tower longitudinally.

18. The substructure according to claim 17, wherein the device for moving the tower is a jacking device, a hoisting device, a pulling device, a driving device or a pushing device.

19. The substructure according to claim 13, wherein the substructure comprises a guiding means, for guiding the tower while moving the tower longitudinally.

20. The substructure according to claim 13, wherein the substructure comprises a compartment for ballast.

21. The substructure according to claim 20, wherein the substructure is configured to be transportable when its longitudinal axis is substantially horizontal and to be upendable by ballasting.

22. The substructure according to claim 13, wherein the substructure comprises a tower for an offshore wind turbine.

23. The substructure according to claim 13, wherein the substructure comprises a locking mechanism for locking the tower into a position.

24. The substructure according to claim 13, wherein the substructure comprises a load-carrying device for carrying a load.

25. The substructure according to claim 24, wherein the load-carrying device is tiltable and configured to carry a load from a vessel onto the substructure.

26. The substructure according to claim 13, wherein the substructure comprises a guiding means for guiding the tower in the container as the tower is moved longitudinally.

27. The substructure according to claim 26, wherein the guiding means comprises one or more of a roller, a gliding plate, and a belt.

28. The substructure according to claim 26, wherein the guiding means is configured to guide a moving structure of varying diameter.

29. The substructure according to claim 28, wherein the guiding means if configured to support a moving structure of varying diameter.

30. The substructure according to claim 26, wherein at least one guiding means is attached to a wall of the container in the substructure and/or wherein at least one guiding means is attached to the tower.

31. The substructure according to claim 26, wherein at least one guiding means is attached to a top portion of a wall of the container in the sub-structure and/or wherein at least one guiding means is attached to a lower portion of the tower.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In the following is described exemplary embodiments illustrated in the accompanying drawings, wherein:

[0043] FIG. 1 shows a side view of an embodiment of the substructure comprising a full-length tower in the container of the substructure;

[0044] FIG. 2 shows a cross-sectional view of an embodiment of the substructure;

[0045] FIG. 3 show a perspective view of the top of an embodiment of the substructure;

[0046] FIG. 4 shows a perspective view of the bottom of an embodiment of the tower;

[0047] FIG. 5 shows a front view of an embodiment of the substructure with an upper section of the tower protruding from the upper end of the container, with a nacelle having been installed onto the upper section of the tower;

[0048] FIG. 6 shows a side view of an embodiment of the substructure with a nacelle and with a first blade having been installed, with the tower in a lowermost position;

[0049] FIG. 7 shows a front view of an embodiment of the substructure with a nacelle and a first blade installed, as a second blade is being installed, with the tower in an intermediary position;

[0050] FIG. 8 shows a front view of an embodiment of the substructure as a third blade is being installed, with the tower in an intermediary position; and

[0051] FIG. 9 shows a front view of an embodiment of the substructure with the tower in an uppermost position.

DETAILED DESCRIPTION OF THE DISCLOSED EXEMPLARY EMBODIMENTS

[0052] Note that the embodiments illustrated in the drawings are shown highly simplified and schematic, and that various features are not necessarily drawn to scale. Identical reference numerals refer to identical or similar features in the drawings.

[0053] FIG. 1 shows a substructure 1 according to the second aspect of the disclosure, in its upright, operational position. The substructure 1 comprises a tower 2, housed inside a container (not shown) in the substructure 1. At the top of the substructure 1, the top of the tower 2 can be seen protruding from the container. Furthermore, a device 13 for moving the tower 2 is shown at the top of the substructure 1. This device 13 for moving the tower 2 in this embodiment is a winch 13 for hoisting the tower 2.

[0054] In FIG. 2, there is shown a substructure 1 where the depth of the container 11 is substantially equal to the height of the tower 2, such that the tower 2 can fit substantially in its entirety, in full length, in the container 11. Thus, there is no need to fold or retract or otherwise compress the length of the tower 2 to fit it substantially in its entirety in the container 11 of the substructure 1.

[0055] The tower 2 can be moved longitudinally by use of the device 13 for moving the tower 2. This device 13 is shown in more detail in FIGS. 3 and 4. In FIG. 3, the top of the substructure 1 is shown, having a top surface 14. On the top surface there is shown a winch 13a for the device 13 for moving the tower 2 longitudinally. Furthermore, FIG. 3 also shows a guiding means 15a in the form of a roller 15a.

[0056] FIG. 4 shows the bottom of the tower 2. The bottom of the tower 2 in this embodiment, is arranged with a guiding means 15b in the form of a roller 15b. It is further arranged with a fastening means 13c for connecting the tower 2 to the winch 13a (not shown in FIG. 4) via a wire 13b. The winch 13 can be used to lower or raise the tower 2.

[0057] The guiding means 15a, 15b are used to support the tower in the container. As the tower 2 is of uneven radius along its length, to provide sufficient guiding support for the tower 2, the guiding means 15a are capable of geometric adaption. In the embodiment shown in FIG. 3, the guiding means 15a attached to the top of the substructure 1 are telescopic. Geometric adaption is not needed for the guiding means 15b shown in FIG. 4, as they are fixed to the tower 2.

[0058] FIG. 5 shows a nacelle 3 having been installed to the top of the tower 2, with the top of the tower protruding from the top surface 14 of the substructure 1. In this embodiment, the top approximately two metres of the tower 2 protrudes from the container. An installation of the nacelle 3 at a height of two metres above an upper surface of the substructure is highly advantageous compared to an installation at full height of the tower 2. It demands less in terms of equipment, such as a crane and a vessel, and is less complex with regards to relative movement between a vessel and the substructure 1.

[0059] In FIG. 6, a first blade 4 has been installed to the tower 2. In this embodiment, the blade 4 is installed in an upright position. The installation of the first blade 4 may be performed having the blade point in any direction. The blade 4 may be turned from one position to another prior to subsequent installation of further blades. FIG. 6 further shows that the blade 4 is installed with the tower 2 in its lowermost position.

[0060] In FIG. 7, the tower 2 has been locked by use of a locking mechanism (not shown) in an intermediary position for installation of a second blade 4. The first blade 4, in this embodiment is still in an upright position, whereas the second blade 4 is installed inclined downwards.

[0061] FIG. 8 shows a third blade 4 being installed, inclined downwards on an opposite side of the tower 2 relative to the second blade 4. The tower 2, in this embodiment, is still in the intermediary position for the installation of the third blade. In other embodiments, the tower 2 may e.g. be in its uppermost position for the installation of the second and/or third blade 4 or in the lowermost position for the installation of the second and/or third blade 4.

[0062] In FIG. 9, the tower 2 is shown in its uppermost position, with all three blades. At this point, the substructure with the tower 2, the nacelle 3 and the blades 4 installed, what is shown is a fully operational offshore wind turbine 10.

[0063] The substructure 1 according to the second aspect of the disclosure can enable the method of the first aspect of the disclosure. It may, however, be possible to perform the method using another type of substructure.

[0064] The Figures shows different steps of an installation of a wind turbine 10 and/or the wind turbine 10 at different stages of an installation.

[0065] A complete installation of the wind turbine 10 may involve several method steps, including one or more steps of the method according to the first aspect of the disclosure. One example of such an installation procedure is described below:

[0066] A substructure 1, in the form of a spar buoy, having an open container 11 for housing a tower 2 for an offshore wind turbine 10 is provided in a body of water laying with its longitudinal axis oriented substantially horizontally. The tower 2 is then provided into the body of water, with its longitudinal axis oriented substantially horizontally, and is floated into the container 11 of the substructure 1. When being floated into the container 11, the tower 2 is guided by guiding means 15a, 15b. Means for driving, pulling, pushing or otherwise physically moving the tower 2 into the chamber can be used.

[0067] The tower 2, when having been floated into and to the bottom of the container 11, being approximately two meters longer than the container 11, protrudes slightly from the container when in position in the container. A substructure 1 having a tower 2 housed in a container of the substructure and slightly protruding from the container is shown in FIG. 1.

[0068] When the tower 2 is in position and secured in the container 11, the substructure 1 is towed to a position at sea for installation of the wind turbine 10.

[0069] When the substructure 1 has been towed to the position for installation of the wind turbine 10, it is upended by ballasting, so as to orient the longitudinal axis vertically. The tower 2 protrudes from the container 11 of the substructure 1 and is thus ready for installation of a nacelle 3 onto the tower 2.

[0070] The nacelle 3 and three blades are carried to the position for installation by a vessel. The substructure 1, in this example, has a tiltable frame for carrying equipment from the vessel. This frame was installed onto the substructure 1 prior to towing the substructure 1 to the position at sea. By use of the frame, the nacelle 3 is carried from the vessel and onto the substructure for installation onto the tower 2.

[0071] When the nacelle 3 has been installed, as seen in FIG. 5, the blades can be installed. Two blades are then installed with the tower 2 kept at the same height as when the nacelle 3 is installed. The tower 2 is then raised to an intermediary position prior to installation of the third blade. When the blades have been installed, the tower is raised into its uppermost position, and the wind turbine 10 made ready for turning wind energy into electrical energy.

[0072] Note that what is described is an example of an installation, and that the method according to the invention that is claimed below may include only one or a few of the steps, and/or alternatives to many of the steps laid out above.

[0073] It should be noted that the above-mentioned embodiments illustrate rather than limit the claimed invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.

[0074] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.