GB2592934A

GB2592934A - Offshore wind turbine system

Info

Publication number: GB2592934A
Application number: GB2003460.9A
Authority: GB
Inventors: Mackinnon Calum
Original assignee: SCOTSTREAM GENERATION Ltd
Current assignee: SCOTSTREAM GENERATION Ltd
Priority date: 2020-03-10
Filing date: 2020-03-10
Publication date: 2021-09-15
Also published as: GB202003460D0

Abstract

A wind turbine assembly 200 comprising a rotatable blade assembly 202, a tower 208, a generator 206 mounted to the base of the tower, and a driveshaft (fig.15, 210) connected to the blade assembly and the generator. The assembly may be an off-shore assembly and the blades may be mounted horizontally and connected to the tower via a bearing and the drive shaft may be located concentrically in relation to the bearing. The blade assembly and/or base may comprise a right-angle gearbox (fig.15, 212). There may be a generator export conduit. The base may comprise floats 220. There may be a fish farm. A mooring system assembly comprising a floating structure, an export conduit, and a mooring buoy anchored to the seabed comprising connecting means e.g. locking pins, and an export and dynamic conduit connector. The structure comprises a tensioning system e.g. pulleys, which maintains tension in the export conduit and a conduit drum that may be fixed to the structure via a bearing. The mooring buoy may be generally cylindrical/ bell-shaped. The system may comprise a base which is connected to floats. An offshore energy generation system comprising a wind turbine assembly and a mooring system as previously described.

Description

OFFSHORE WIND TURBINE SYSTEM

FIELD OF THE INVENTION

The present invention relates to a floating wind turbine system that weathervanes on a single point mooring arrangement. The invention may also relate to a continuity connector for power transmission which may be used in conjunction with a floating wind turbine system. Further to this, the invention may relate to a floating wind turbine which has a generator unit mounted at the base of the tower, rather than at the top of the tower.

BACKGROUND OF THE INVENTION

Wind turbines are used to convert wind energy into electrical energy which goes on to be used for powering homes and commercial buildings. Offshore wind is being used more frequently as energy suppliers seek alternative ways to harvest the earth's natural resources. As average wind speeds are higher offshore than onshore, each turbine has the potential to generate more electricity than its onshore equivalent: making offshore an attractive opportunity for energy suppliers.

However, offshore wind energy comes with some significant challenges. Firstly, the depth of the water dictates whether the wind turbine must be fixed to the seabed or whether it must be located on a floating structure. The cost of shipping and maintaining a wind turbine offshore is higher than the onshore equivalent, due to the access difficulties. Further to this, support during the lifetime and installation vessels are expensive, which also adds expense to the wind turbine.

Currently, offshore wind turbines are very similar in terms of construction and design to their onshore equivalents, albeit they are usually larger. The two main types of wind turbine are horizontal axis (HAVVT) and vertical axis (VAVVT). Due to their efficiency and scalability, horizontal axis wind turbines are the most popular for energy generation.

A horizontal wind turbine typically contains 3 main structural components: blades, a nacelle, and a tower. The nacelle is usually located at the top of the tower near the blades, and contains a gearbox, generator, and control equipment. The equipment in the nacelle can weigh up to 750 tonnes for a 15 MW unit. Although this is not a problem for onshore wind turbines, it can present a problem for floating offshore wind turbines. The floating structure must be large enough to counteract the heavy mass of the nacelle which is located on top of the tower (which can be 100-150 meters long). Further to this a multi-leg mooring system is required in order to maintain the large floating structure in its location in the sea. Another issue which may arise is if the heavy generator or any of the heavy components in the nacelle need replacing, a difficult operation which requires good weather must be performed. Assembling the wind turbine offshore will require a high lift crane and vessel. Transferring heavy equipment at height onto a moving vessel at sea is a very challenging task and is a very weather sensitive operation. Both capital costs and operational costs would be very high for this type of assembly.

Another issue with floating vessels is the difficulty of transferring power whilst allowing the vessel to weathervane. The solution in the art is to use a slip ring, which uses a series of brushes to transmit power from one rotating body to another. Slip rings are expensive, unreliable, and cannot cope with high power loads.

For the above reasons, there remains a need to address or mitigate at least one or more of the aforementioned problems. A large change in the design of offshore wind turbines is required to make the industry economically viable.

It is therefore an object of the present invention to provide a new tower configuration where the heavy generator is mounted at the base of the tower, thereby reducing the structural load on the tower, reducing the size and weight of the nacelle, and making maintenance easier and safer. The generator can easily be moved from the floating structure to a supporting vessel using a handling system.

Another object of the present invention is to provide a handling winch which is mounted at the bottom of the tower to install or remove blades, thus removing the requirement to have a high crane vessel to support the operation of assembling the wind turbine. A gantry system may also be included in the nacelle to provide component handling.

Another object of the present invention is to provide a single point weathervaning mooring system which allows the structure to weathervane around a mooring point, whilst preventing the need for an expensive multi leg mooring system. Part of the mooring system will contain a rotational continuity connector, to enable continuous power transmission whilst allowing the floating structure to rotate freely.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a wind turbine assembly comprising: a rotatable blade assembly mounted on top of a tower, a generator mounted at the base of the tower, and a driveshaft operatively connected to the blade assembly and the generator.

The rotatable blade assembly may be mounted horizontally, thereby forming a horizonal axis wind turbine. The blade assembly may comprise a plurality of blades. For example, there may be 3 blades.

The assembly may be an off-shore assembly. The assembly may also be used onshore or inshore.

The rotatable blade assembly may comprise a right-angle gearbox. The gearbox may be operatively connected to blades in the blade assembly and the driveshaft. The generator may easily be moved at deck level onto a supporting vessel using a handling system.

The rotatable blade assembly may be connected to the tower via a bearing. The drive shaft may be located concentrically in relation to the bearing. This may allow the blade assembly to rotate about the tower whilst still transferring power to the drive shaft. The right-angle gearbox may be connected to the blade assembly to transfer power from the blades to the driveshaft. If the blade assembly is operating in the horizontal orientation, the right-angle gearbox will transfer power from the horizontal axis to the vertical axis. By being located concentrically in relation to the bearing, the driveshaft can continue to rotate whilst the rotatable blade assembly rotates about the tower.

The base of the tower may comprise a right-angle gearbox. This may be connected to the driveshaft in the tower, transferring the rotational power from the vertical axis to a horizontal axis. This may allow a generator to be mounted in a horizontal manner within the base of the tower. This configuration allows a standard wind turbine's generator to be used, but instead of being located in the top of the tower, it must be moved to the base of the tower. With the addition of two right-angle gearboxes and a vertical drive shaft, a standard wind turbine setup may be used.

Alternatively, a plurality of generators may be located in the base of the tower. The gearbox may be fitted with multiple outputs which may feed into the plurality of generators. This may be easier than installing one large generator.

The assembly may further comprise a generator export conduit.

The assembly may further comprise a base structure. The base structure may have a plurality of floats attached to it.

The assembly may further comprise a fish farm.

According to a second aspect of the present invention, there is provided a mooring system assembly comprising: a floating structure and a mooring buoy, the mooring buoy comprising connecting means for connecting to the floating structure; and an export conduit; wherein the mooring buoy is suited to be anchored to the seabed in a fixed orientation relative to the seabed and wherein the mooring buoy comprises an export conduit connector and a dynamic conduit connector; wherein the floating structure is suited to freely rotate about the mooring buoy, and wherein the floating structure comprises a tensioning system which maintains tension in the export conduit; wherein the floating structure comprises at least one export conduit drum; and wherein when the mooring buoy is connected to the floating structure, the at least one export conduit drum remains in a fixed orientation relative to the mooring buoy.

The connecting means on the mooring buoy may be generally cylindrical. The connecting means may define a first longitudinal axis which extends along the main cylindrical axis of the connecting means.

The export conduit drum may comprise a second longitudinal axis which extends through the export conduit drum and is aligned with the longitudinal axis of the conduit drum. When the mooring buoy and floating structure are connected, the second longitudinal axis may be generally aligned with the first longitudinal axis.

The connecting means may comprise locking pins to secure the mooring buoy to the floating structure. The locking pins may also fix the export conduit drum and the mooring buoy in the same orientation. A series of locking pins may lock the conduit drums to the mooring buoy, thus reducing the vertical load. The locking pins may be supported by the slew bearing. The locking pins may also lock the orientation of the mooring system and conduit drums.

The export conduit drum may be connected to the floating structure via a bearing. The bearing may allow the drum to freely rotate when the mooring buoy is not connected.

The floating structure may comprise hoisting means to hoist the mooring buoy into the floating structure.

The mooring buoy may be generally bell-shaped.

The tensioning system may comprise a plurality of pulleys which form the export conduit into a catenary shape.

An off-shore energy generation system, wherein the wind turbine assembly according to the first aspect of the present invention is connected to the mooring system according to the second aspect of the present invention. The mooring system should not be limited to floating wind turbines, but may be used in combination with other undisclosed systems.

Any of the previously described inventions may also be coupled with a fish farm as described in the description below.

Further optional features disclosed in relation to each aspect of the invention correspond to further optional features of each other aspect of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting example embodiments the present invention will now be described with reference to the accompanying drawings in which: Figure 1 shows an onshore wind turbine, in accordance with the prior art, showing the generator at the top of the tower, located inside the nacelle; Figure 2 shows an embodiment of the present invention, depicting the sea surface and seabed; Figure 3 shows an embodiment of the present invention, depicting the seabed, mooring lines, and a dynamic umbilical; Figure 4 shows an embodiment of the present invention, depicting the floating structure; Figure 5 shows an embodiment of the present invention with an integrated fish farm; Figure 6 shows an embodiment of the present invention, detailing the attachments to the floating structure; Figure 7 shows an embodiment of the present invention, detailing the continuity connector assembly; Figure 8 shows a cross sectional view of the continuity connector assembly according to Figure 7; Figures 9 and 10 show a termination head being inserted into the continuity connector assembly; Figures 11 and 12 show the continuity connector assembly according to Figures 7 to 10 in two different configurations, where Figure 11 has more conduit wrapped around the drum than in Figure 12; Figure 13 shows the continuity connector assembly according to the present invention used in combination with a tidal stream device; Figure 14 shows a wind turbine embodiment according to the prior art and a wind turbine embodiment according to the present invention; Figure 15 shows a wind turbine according to the present invention, detailing the vertical drive shaft and connected components; Figure 16 shows a detailed view of the drive shaft and connected components from Figure 15.

DETAILED DESCRIPTION

A description of the figures is given below. Figure 1 shows a cross section of a wind turbine 100 according to the prior art, showing blades 102, a tower 108, a nacelle 104, and a generator 106. The generator 106 is housed at the top of the tower 108 inside the nacelle 104, and the nacelle 104 and blades 102 usually pivot about the tower 108 to weathervane into the wind. As these types of wind turbine 100 are suitable for onshore operations, there are no significant disadvantages with locating a heavy generator 106 at the top of the tower 108. However due to weight restrictions, this type of arrangement is not suitable for offshore operations.

Figure 2 shows an embodiment of the present invention, showing the sea surface 201 and the sea bed 203. The wind turbine assembly 200 can be seen floating on the sea surface 201, whilst the mooring lines 205 can be seen to be attached to the sea bed 203. The wind turbine assembly 200 is attached to a floating structure 302 which comprises floats 220 to prevent the structure from sinking. The water depths which the floating wind turbine is operable in, may vary from 25 to 1500 metres deep.

Figure 3 is similar to Figure 2; however, the sea surface has been removed for clarity. The mooring system assembly 300 and the floating structure 302 can now more easily be seen.

The mooring system 300 is held in place by the mooring lines 205 whilst remaining in the same location and orientation above the sea bed 203. The mooring system 300 provides a rotational coupling to the floating structure 302 and therefore the wind turbine assembly 200. The floating structure 302 weathervanes around the mooring system 300 enabling the wind turbine 200 to always face into the prevailing wind. Further to keeping the structure in one location, the mooring system 300 also electrically connects the wind turbine assembly 200 to electrical conduits on the sea bed 203, known as dynamic conduits 305. The dynamic conduit 305 is shown in Figure 3 and Figure 6. Electrical conduits may comprise a plurality of electrical cables. These dynamic conduits 305 on the seabed may be connected to the national grid network via subsea cables. A dynamic conduit 305 can be seen extending from the sea bed 203 to the mooring system 300. The dynamic conduit 305 will connect with the export conduit 222/306 coming from the wind turbine assembly 200, providing a continuous electrical connection between the generator in the wind turbine to the seabed electrical network. Conduits described should not be limited to electrical conduits, but may be for transporting any medium such as water transport, energy, solids transport, control signals etc. Figure 4 shows a detailed view of the floating structure 302. The floating structure 302 comprises three floats 220 as shown, however this should not be taken to be limiting. The structure may comprise more than 3, and in different configurations. As shown in Figure 3, the floating structure 302 is moored as part of the mooring system 300. The mooring buoy 304 which connects to the floating structure 302 may be connected to the float which is shown on the left of the image for example. The mooring system 300 is positioned at the 'front' of the floating structure 302, such that the majority of the mass of the floating structure 302 is aft of the mooring system 300. This design ensures that if connected to a wind turbine system 200, the wind turbine will always be arranged in the correct orientation relative to the wind, as the mass of the system will assist the process of weathervaning.

Further to this, the nacelle 204 may also yaw into wind at a different angle from the heading of the floating structure 302, thus assisting the weathervaning process. This may occur when the waves and tides are orienting the floating structure 302 one direction, and the prevailing wind orients the blades 202 of the wind turbine another direction.

In use, the floating structure 302 is located below the waterline, with the floats 220 protruding slightly above the sea surface 201. Floats 220 are provided on either side of the tower 208 to prevent the tower 208 and wind turbine assembly 200 from overturning due to side-wind forces. The design of the floats 220 protruding above the sea surface 201 provide protection against high roll rates and displacements of the system. If the base structure 218 rolls, one of the floats 220 will submerge further into the sea, thus increasing the buoyancy force from the float 220, thus counteracting the roll. The floats 220 will be sized to suit the loading of the waves, weight of the assembly, and weather conditions expected. Base plates are also incorporated into the present embodiment, to increase the drag force on the floating structure, thereby reducing the heave velocity of the structure through the water. This improves stability and safety of the assembly.

In the embodiment in Figure 4, the base of the tower 208 of the wind turbine assembly 200 is joined to a float 220. To reduce roll of the wind turbine 200, the generator 206 and other heavy equipment from the nacelle 204 is housed in the base of the tower 208. This arrangement significantly lowers the centre of gravity of the wind turbine assembly 200, thus reducing the moment force causing the rolling motion. This will be further described in Figures 14 and 15.

Figure 5 shows another embodiment of the present invention, similar to the base structure 218 shown in Figure 4, however the structure 218 further comprises an integrated fish farm 224. The fish farm 224 may be configured to suit any type of fish, with suitable sized bins to ensure comfort for the fish whilst preventing them from escaping. The floating structure fish farm 224 may also be configured for use with any offshore system, such as a wave energy device or a tidal energy device.

Figure 6 shows a side view of the wind turbine assembly 200, the base structure 218, and the mooring system 300. The mooring lines 205 and the dynamic conduit 305 can be seen to extend from the sea bed 203 to the mooring system 300. The base structure 218 can also be seen in an example position relative to the sea surface 201.

Figures 7 and 8 show another aspect of the present invention. A mooring system 300 is shown, comprising a floating structure 302 (which may attach onto one of the floats 220) and a mooring buoy 304. The mooring buoy comprises connecting means 308 for connecting to the floating structure 302. The mooring system 300 also comprises an export conduit 306, which may be connected to the generator export conduit 222 of the wind turbine assembly 200.

The mooring system 300 enables the export conduit 306 to attach to the dynamic conduit 305 directly, without any breaks in the electrical circuitry, whilst permitting the floating structure 302 to move freely around the mooring buoy 304. This is important for high voltage and high-power operations such as are experienced in offshore power generation.

As mentioned previously the floating structure 302 may be fixed to the off shore wind turbine assembly 200. Specifically, the floating structure 302 may be fixed to the one of the floats 220 on the base structure 218. The mooring buoy does not rotate relative to the sea bed, however the floating structure 302 and its components rotate about the mooring buoy 304. The mooring buoy further comprises an export conduit connector 310 and a dynamic conduit connector 312, which connect to the export and dynamic conduits respectfully.

To enable power transmission there must be some form of rotary connection between sea bed 203 and the wind turbine assembly 200. The standard component for transferring electrical power between rotating components is a slip ring. This is a device which transfers electrical power through a series of contacting brushes. Slip rings are usually designed for low levels of power transmission and are therefore not suitable for large operations such as high voltage wind turbine output. Further to this, slip rings require a lot of maintenance and are unreliable in operation.

The mooring system assembly 300 as shown in Figures 7 and 8 provides a solution to the above-mentioned problem. An export conduit drum 316 is shown affixed to the floating structure 302 on the bearing element 322. The export conduit drum 316 provides a reel for the export conduit 306 from the wind turbine to wind onto. There are a plurality of conduit drums 316 shown in Figure 7. The plurality of drums 316 can be used to reel different conduit diameters and lengths, as export conduits 306 can often carry various sizes of cable/conduit. For example, if the dynamic conduit 305 on the seabed 203 comprised 4 cables, these 4 cables would extend from the seabed 203 and terminate in 4 separate dynamic conduit connectors 312 on the mooring buoy 304. These 4 cables would each be wound around a separate conduit drum 316 which is suited for their size. This enables easier management of cables and conduits.

As is shown in Figure 8, the assembly 300 also comprises a tensioning system 314. The export conduit 306 runs from the right side of the image over the pulley wheels 326 (part of the tensioning system 314) and onto the conduit drum 316, before passing down to the mooring buoy 304, where the conduit connects to the export conduit connector 310. An electrical connection is then made between the export conduit connector 310 and the dynamic conduit connector 312, which allows the dynamic conduit 305 from the sea bed 203 to be connected.

Figures 9 and 10 show an illustrative embodiment of the mooring system 300. Figure 9 shows the mooring buoy 304 being inserted into the floating structure 302, and Figure 10 shows the mooring buoy 304 fully inserted. This mooring buoy 304 may be lifted into the floating structure via the hoisting means 324. The mooring buoy 304 comprises a connecting means 308 for connecting on to the floating structure 302. This may be a shaft with suitable locking pins for example.

When the mooring buoy 304 is connected to the floating structure 302, the conduit drum 316 remains in a fixed orientation relative to the mooring buoy 304, to allow the export conduit 306 to reel onto the conduit drum 316 when the floating structure 302 rotates about the mooring buoy 304. This may be done via a splined connection. The conduit drum 316 is shown to be connected to the floating structure 302 via a bearing 322 to allow the drum to freely rotate when the mooring buoy 304 is not connected.

The connecting means 308 on the mooring buoy 304 may be generally cylindrical and may define a first longitudinal axis 320 along the main cylindrical axis. The export conduit drum 316 may comprise a second longitudinal axis 318, which extends through the longitudinal axis of the conduit drum 316. When the mooring buoy 304 and the floating structure 302 are connected, the first and second longitudinal axes 318/320 are generally aligned.

The mooring system 300 will allow the floating structure 302 to weathervane a predetermined number of rotations before being reset back to the original orientation/configuration. For example, the mooring system 300 may be set up to allow 30 rotations before needing to be reset. More rotations would be possible by using a greater length of export conduit 306 from the wind turbine assembly 200, increasing the capacity, or by reducing the diameter of the conduit drum 316. The number of rotations specified may depend on weather conditions and the frequency of maintenance.

After the mooring system is located, as shown in Figure 10, locking pins may be used to prevent the mooring system from separating from the floating structure. These locking pins may support the vertical mooring loads from waves and weather etc. The mooring buoy 304 is connected to the floating structure 302 via the connecting means 308. The connecting means 308 must allow the floating structure 302 to rotate about the mooring buoy 304 without restriction, and may comprise a bearing element 322. The bearing may allow rotation with low friction. This bearing may be a slew bearing. All of the components above the bearing remain in the same orientation as the mooring buoy 304, which remains in the same orientation relative to the seabed 203. The floating structure 302 and all of its components (including the pulleys 326 in the tensioning system 314 and export conduit 306) are free to rotate around the mooring buoy 304, via weathervaning action. As the export conduit 306 is routed around the drum 316 and then down through to connect to the export conduit connector 310, the conduit 306 will therefore 'wrap' and 'unwrap' itself onto the conduit drum 316 without any damage taking place or any human intervention.

The mooring buoy 304 may comprise a splined connector to connect onto the conduit drum 316 on the floating structure 302. The splined connector may be replaced with any other suitable type of connector which prevents relative rotation between components. For example, locking pins may be inserted into the continuity connector after it has been hoisted into position as in Figure 10. The locking pins may also reduce the vertical loads on the connector.

For example, one 360-degree rotation of the floating structure 302 via weathervaning action about the mooring buoy 304, will result in one rotation of conduit 306 being wrapped onto the conduit drum 316. This should reduce the slack in the catenary arrangement by the circumference of the conduit drum 316 (approximately). If the floating structure 302 weathervanes in the opposite direction for 360 degrees, then the catenary arrangement will increase in length again, whilst keeping tension on the conduit. This arrangement provides a solution to the problem as described previously. The tensioning system 314 as described above should not be limited to the pulley/catenary arrangement, but may be any other suitable form of system which provides tension to the export conduit 306.

As shown in Figures 11 and 12, the export conduit 306 runs over and through the pulley wheels 326 which are part of the tensioning system 314 before being wound onto the conduit drum 316. The conduit 306 forms a suspended catenary, which is long in Figure 12, and short in Figure 11. There is therefore more conduit 306 on the conduit drum 316 in Figure 11 than there is in Figure 12. This apparatus provides a self-tensioning arrangement, keeping the deck of the floating structure 302 free from unravelled conduit 306. The arrangement of the pulleys 326 also keeps the conduit drum 316 tidy and provides for good winding properties. The export conduit 306 then runs into the wind turbine assembly 200 and is connected to the generator 206. This system provides a continuous connection between the generator 206 of the wind turbine 200 and the sea bed electrical grid in a novel and inventive way.

Conduit management systems may be used to arrange the conduit 306 over the tensioning system 314 and onto the conduit drums 316. The complexity of these systems will depend on the amount of power generated by the wind turbine system 200.

If the chosen limit of the conduit drum 316 is 30 rotations, then the floating structure 302 may weathervane around the mooring buoy 304 60 times (30 clockwise and 30 anticlockwise). Once these limits have been reached, the conduit drums 316 will need to be reset. A support vessel may be used to physically rotate the floating structure 302 30 times around the mooring buoy 304 until the starting orientation is reached. Alternatively, the dynamic conduit 205 could be disconnected from the export conduit connector 310, and a drive motor could be used to rotate the conduit drums 316, thus unwinding the conduit 306 from the drum.

As a safety precaution, a drive motor may be used to turn the conduit drums 316 relative to the mooring buoy 304, if the system develops a fault for example. This would prevent any twisting in the mooring system 300 and potential damage to the electrical conduit (export or dynamic).

The mooring system as described above may be used for any off shore weathervaning structure, such as floating wind devices, wave energy devices, tidal stream devices etc. An example of this can be seen in Figure 13 which shows an example of the present invention. The base structure 218, floats 220 and mooring system 300 are used for a tidal stream application. The tidal stream turbines 250 are shown to be mounted on the floats 220. The tidal stream device weathervanes around the mooring system 300 so that the turbines 250 are always heading into the tidal stream flow.

Another embodiment of the present invention is shown in Figures 14b and 15. Figure 14a shows an illustration of a wind turbine 100 according to the prior art, fixed onto a floating ballast. The generator 106 is positioned in the nacelle 104 at the top of the tower 108 as is usual in the prior art. The generator 106 is a heavy object and exerts a large pitching moment onto the wind turbine structure. To counteract this, a large floating ballast is required: as is shown.

Figure 14b shows an example of the present invention, showing the generator 206 of the wind turbine 200 positioned at the bottom of the tower 208. This dramatically reduces pitching loads on the wind turbine, therefore reducing the requirement for such a large floating ballast 220 (as can be seen). A right-angled gearbox 212 is located in the nacelle 204, which transmits the horizontal rotational power from the blades 202 to a vertical drive shaft 210, which transfers the power to the generator 206 which is located in the base of the tower 208. The nacelle 204 in this example can be driven to yaw into the wind, keeping the blades 202 facing the prevailing wind. The nacelle 204 yaws about the tower 208 on a slew bearing. The generator 206 is mounted concentrically with the slew bearing, and is located in the base of the tower 208. As the gearbox 206 is mounted concentrically with the bearing, the turbine can continue to transmit power as the nacelle 204 yaws.

Figures 15 and 16 show a cross section of the embodiment in Figure 14b. Figure 15 shows the right-angle gearbox 212, the driveshaft 210 and the generator 206 removed from the turbine assembly 200. Also seen in Figure 15 is the base structure 218 with the floats 220 attached to it. A detailed view of the driveshaft 210 and the generator 206 in the base of the tower 208 can be seen in Figure 16. The generator 206 can be mounted horizontally and can be connected to a second right angled gearbox 212. This may be connected to the bottom of the driveshaft 210. Alternatively, the generator 207 can be mounted vertically and connected directly to the drive shaft 210.

Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the present invention.

Claims

CLAIMS 2. 4. 5. 6. 7. 8.A wind turbine assembly comprising: a rotatable blade assembly mounted at the top of a tower, a generator mounted at the base of the tower, and a driveshaft operatively connected to the blade assembly and the generator.
A wind turbine assembly according to claim 1, wherein the rotatable blade assembly is mounted horizontally, thereby forming a horizonal axis wind turbine.
A wind turbine assembly according to either claim 1 or 2, wherein the assembly is an off-shore assembly.
A wind turbine assembly according to any preceding claim, wherein the rotatable blade assembly comprises a right-angle gearbox, and wherein the gearbox is operatively connected to blades in the blade assembly and the driveshaft.
A wind turbine assembly according to any preceding claim, wherein the rotatable blade assembly is connected to the tower via a bearing, and wherein the drive shaft is located concentrically in relation to the bearing.
A wind turbine assembly according to any preceding claim, wherein the base of the tower comprises a right-angle gearbox.
A wind turbine assembly according to any preceding claim, wherein the assembly further comprises a generator export conduit.
A wind turbine assembly according to any preceding claim, wherein the assembly further comprises a base structure, wherein the base structure has a plurality of floats attached to it.
9. An assembly according to any preceding claim, wherein the assembly further comprises a fish farm.
10. A mooring system assembly comprising: a floating structure and a mooring buoy, the mooring buoy comprising connecting means for connecting to the floating structure; and an export conduit; wherein the mooring buoy is suited to be anchored to the seabed in a fixed orientation relative to the seabed and wherein the mooring buoy comprises an export conduit connector and a dynamic conduit connector; wherein the floating structure is suited to freely rotate about the mooring buoy, and wherein the floating structure comprises a tensioning system which maintains tension in the export conduit; wherein the floating structure comprises at least one export conduit drum; and wherein when the mooring buoy is connected to the floating structure, the at least one export conduit drum remains in a fixed orientation relative to the mooring buoy.
11. A mooring system according to claim 10, wherein the connecting means on the mooring buoy is generally cylindrical and defines a first longitudinal axis which extends along the main cylindrical axis of the connecting means.
12. A mooring system according to either of claims 10 or 11, wherein the export conduit drum comprises a second longitudinal axis which extends through the export conduit drum and is aligned with the longitudinal axis of the conduit drum and, when the mooring buoy and floating structure are connected, the second longitudinal axis is generally aligned with the first longitudinal axis.
13. A mooring system according to any of claims 10 to 12 wherein the connecting means comprise locking pins.
14. A mooring system according to any of claims 10 to 13, wherein the export conduit drum is connected to the floating structure via a bearing, allowing the drum to freely rotate relative to the floating structure.
15. A mooring system according to any of claims 10 to 14 wherein the floating structure comprises hoisting means, to hoist the mooring buoy into the floating structure.
16. A mooring system according to any of claims 10 to 15, wherein the mooring buoy is generally bell-shaped.
17. A mooring system according to any of claims 10 to 16, wherein the tensioning system comprises a plurality of pulleys which form the export conduit into a catenary shape.
18. A mooring system according to any preceding claim, wherein the system further comprises a base structure, wherein a plurality of floats are connected to the base structure.
19. An off-shore energy generation system wherein the wind turbine assembly according to any of claims 1 to 9 is connected to the mooring system according to any of claims 10 to 18.