GB2451191A

GB2451191A - Wind turbine mounting

Info

Publication number: GB2451191A
Application number: GB0813235A
Authority: GB
Inventors: Peter Ronald Chambers
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-07-18
Filing date: 2008-07-18
Publication date: 2009-01-21
Anticipated expiration: 2028-07-18
Also published as: WO2009010771A2; EP2183480A2; WO2009010771A8; GB0713990D0; WO2009010771A3; GB2451191B; GB0813235D0

Abstract

A mounting 14 is provided on which a wind turbine 12 is mountable, the mounting 14 preferably including a column 28. A method of assembling a mounting 14 for a wind turbine 12, the mounting 14 including a column 28, includes erecting the column 28. The column 28 may be locatable within a socket 38 of a base 30 which is located under water. The column 28 may comprise telescopically arranged members 32, 34, 36. The turbine 12 may drive one or more generators via a shaft 22 to generate electricity. The method of erecting the column 28 may include sequentially jacking and supporting the telescopic members 32, 34, 26.

Description

Mountings The present invention relates to mountings, particularly but not exclusively mountings for wind turbines, and methods of assembling such mountings.

Conventionally, wind turbine assemblies comprise a wind turbine, the wind turbine including a drive assembly in the form of a plurality of rotor blades which are mounted to a hub, the hub being mounted to a shaft, the shaft driving a generator to generate electricity as the rotor blades turn, the blades being driven by the wind, the shaft and the generator being mounted within a housing. The wind turbine is rotatably mounted to a mounting including a column, which conventionally is formed of steel.

The generating capacity of such wind turbine assemblies is directly linked to the length of the rotor blades, or rather, the area swept by the rotor blades, which is limited by the height of column. Conventional wind turbine assemblies are currently limited to energy capacities of approximately 5 MW.

The use of new construction methods and relatively exotic materials is anticipated to increase the capacity to between 7 and 10 MW. In comparison with conventional power plants such as coal fired power plants, which can have capacities of, for example, 500 MW, such small power plants are relatively expensive in terms of capital cost per unit energy generated. Such plants are often installed in remote areas such as hills or in the sea, so that the maintenance costs are also higher. Increasing the size of wind turbine assemblies will reduce costs.

According to a first aspect of the present invention, there is provided a mounting on which a wind turbine is mountable, the mounting including a column.

Possibly the mounting includes a base. Possibly the column is mountable to the base.

Possibly the base includes an engaging formation, for engaging the column. Possibly the engaging formation is in the form of a socket, defined by the base, in which at least a part of the column is receivable. Possibly the socket is polygonal in plan, and the part of the column receivable within the socket may be shaped to correspond with the shape of the socket. Possibly the socket is square in plan.

Possibly the column includes a plurality of members. Possibly the column includes a first member and a second member. Possibly in use the second member is telescopically connected to the first member. Possibly in use the second member projects from the first member.

Possibly the column includes a third member, which may be telescopically connected to the second member, and may project from the second member.

Possibly the column is formed of concrete.

Possibly the base is located under water. Possibly the column is mounted to the base by floating the column into the vicinity of the base, and at least partially sinking the column.

According to a second aspect of the present invention, there is provided a wind turbine assembly, the wind turbine assembly including a wind turbine mounting on which a wind turbine is mountable, the mounting including a column. Possibly the mounting is as described in any of the preceding

statements.

Possibly the wind turbine assembly includes a wind turbine.

According to a third aspect of the present invention, there is provided a wind turbine assembly, the wind turbine assembly including a wind turbine, the wind turbine being mountable on a mounting.

Possibly the mounting is as described in the preceding paragraphs.

Possibly the wind turbine includes a housing.

Possibly the wind turbine includes drive means.

Possibly the wind turbine includes a shaft, and the drive means may be mounted to the shaft. The shaft may be mounted within the housing.

Possibly the wind turbine includes a generator arrangement. Possibly the wind turbine is arranged so that the drive means cause the shaft to rotate, and the rotating shaft causes the generator arrangement to generate electricity.

Possibly the generator arrangement includes a plurality of generators, which may be mounted along the shaft, and may be mounted side by side.

Possibly the drive means include a plurality of blade members, each of which may be mounted directly to the shaft. Alternatively, the drive means may include a hub which is mounted to the shaft and a plurality of blade members which are mounted to the hub. In another alternative, the wind turbine may include a rotor structure. The blade members may be mounted to the rotor structure, which may be mounted to the shaft. The rotor structure may include a plurality of carrier members.

Possibly the wind turbine includes a plurality of spaced shaft mountings, each of which may include bearings to permit rotation of the shaft.

Possibly the wind turbine assembly includes a housing. Possibly the wind turbine assembly includes a housing mounting for rotatably mounting the housing to the column. Possibly the wind turbine assembly includes housing drive means for rotating the housing relative to the column.

According to a fourth aspect of the present invention, there is provided a method of assembly of a mounting for a wind turbine, the mounting including a column, the method including a step of erecting the column.

Possibly the mounting includes a base, and the step may include positioning the base under water. Possibly the erection step includes floating the column into the vicinity of the base. Possibly the erection step includes at least partially sinking the column to mount the column to the base.

Possibly the method includes the step of lifting the assembled column and base to reposition the assembled column and base at another location.

Possibly the lifting is by buoyancy means.

Possibly the column includes a plurality of members.

Possibly the column includes a first member and a second member which are telescopically connected, and the erection step includes the step of extending the second member from a retracted position substantially within the first member to an extended position. Possibly the extending step includes the steps of sequentially jacking and supporting the second member from the retracted position to the extended position. Possibly the steps of jacking and supporting are repeated. Possibly the column defines an interior, and the jacking and supporting is carried out in the interior. Possibly the step of supporting includes building an inner structure formed of support members.

Possibly the structure is in the form of a wall, which may form a lining.

Possibly the column includes one member which is positioned above another member. Possibly the positioning of the one member includes lifting the one member by buoyancy means. Possibly the one member is lifted above water level by the buoyancy means. Possibly the lifting step includes sequentially lifting, holding and packing the one member, and then lifting again.

According to a fifth aspect of the present invention, there is provided a method of assembly of a wind turbine assembly, the wind turbine assembly including a wind turbine mounting on which a wind turbine is mountable, the mounting including a column, the method including a step of erecting the column.

Possibly the method includes any of the steps previously described.

Possibly the wind turbine assembly includes a wind turbine, which may include a housing, and the method includes mounting the housing to the column. Possibly the housing is mounted to the column while the column is in the retracted position. Possibly the housing is lifted by buoyancy means and may be lifted above water level by the buoyancy means.

Possibly the wind turbine includes drive means. Possibly the method includes mounting the drive means, and may include mounting the drive means when the column is in the extended position.

Possibly the wind turbine assembly is as described above in any of the

preceding statements.

Embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figures 1A and 1 B are side and front views respectively of a wind 1 5 turbine assembly; Figure 2 is a front view of another wind turbine assembly; Figures 3A to 3D are side views of a column at different stages of a method of assembly; Figures 4A and 4B are side and plan views of a base; Figure 5 shows side views of the base at different stages of a method of assembly of a mounting for a wind turbine Figures 6 to 10 are side schematic views at different stages of the method of assembly of the mounting; Figures 11 and 12A to 12D are side schematic views of a part of the mounting at different stages of the method of assembly; Figure 13 is a plan view of a wall member in position in the mounting; Figure 14 is a side view of the wall member on arrows A-A of Figure 13; Figure 15 is a side schematic view of part of a mounting and a housing of a wind turbine assembly; Figures 16A to 16L are side schematic views of different stages of another method of assembly of another mounting; Figure 17 is a side schematic view of the mounting of Figures 16A to 16L at one stage of the method of assembly; and Figures 18A to 18C are sectional views of the mounting of Figure 17 as indicated by the arrows A-A, B-B and C-C respectively in Figure 17; Figures 19 and 20 are side schematic views of different stages of another method of assembly of a mounting; Figure 21 is a plan view on arrow A in Figure 20; Figure 22 is a side schematic view of different stages in another method of assembly of a mounting for a wind turbine assembly; Figures 23A and 23B are plan views on arrows A and B respectively in Figure 22C; Figure 24 is a side schematic view of a stage in another method of assembly of a mounting; Figure 25 is a plan view of part of another base; Figure 26 is a side sectional schematic view of the base of Fig 25 in an installed condition; Figure 27 is an enlarged detail of part of Fig 26; Figure 28 is an enlarged detail of part of another base similar to that shown in Figs 25 -27; Figure 29 is a plan view of a support structure in situ within a column member; Figure 30 is a plan view of one of the support members comprising the support structure of Fig 29; Figure 31 is a side sectional view along line A-A of Fig 30 of part of the support member and support structure in situ; Figure 32 is a side sectional view along line B of Fig 30 of part of the support member and support structure; Figure 33 is a side view along arrow C of Fig 32 of part of the support member and support structure; Figure 34 is a side view of parts of several support structures in situ; Figures 35A, 356 and 35C are plan sectional views on lines A,B and C respectively of Figure 34; and Figure 36 is a side view of another base.

Figures 1A and lB show a wind turbine assembly 10, the wind turbine assembly 10 including a wind turbine 12 and a wind turbine mounting 14, the wind turbine 12 mounted on the wind turbine mounting 14. The wind turbine mounting 14 includes a column 28 mounted to a base 30. The base 30 includes an engaging formation in the form of a socket 38 defined by the base 30, in which the column 28 is receivable in an assembled condition. In one example, the socket 38 could be polygonal in shape in cross section, and could, for example, be square, and the part of the column 28 receivable within the socket 38 could be shaped to correspond with the shape of the socket 38.

The column 28 includes a first member 32, a second member 34, and a third member 36, which are telescopically connected to each other, and are moveable between a retracted position in which the third member 36 is substantially received within the second member 34, which in turn is substantially received within the first member 32, and an extended position, in which the third member 36 projects from the second member 34, which projects from the first member 32.

The wind turbine 12 includes drive means 16 which include a plurality of blade members 18 which, in the example shown in Figures 1A and 1B, are mounted to a rotor structure 17 which in turn is mounted to a shaft 22. The wind turbine 12 includes a housing 24 and the shaft 22 is mounted within the housing 24. The rotor structure 17 includes a plurality of carrier members 20, and is arranged so that one carrier member 20 extends between each of the blade members 18 and the shaft 22. The arrangement of the rotor structure 17 permits the blade members 18 to cover a larger swept area 68 than a comparative blade member extending from the shaft 22, the larger swept area 68 permitting greater power to be generated by the wind turbine 12.

Figures 1A and lB show the wind turbine assembly 10 in an installed condition, in which the base 30 is located on a bed 40, which could, for example, be a sea bed, the base 30 being located under water 42 The wind turbine mounting 14 includes a housing mounting 26 for mounting the housing 24 to the column 28. The housing mounting 26 is arranged to permit rotatable mounting of the housing 24 relative to the column 28.

Figures 3 to 12 show stages in a method of assembly of the wind turbine assembly 10. The first column member 32 is formed of a material such as concrete on a floor 44 of, for example a dry dock. The column member 32 includes a hollow cylindrical wall 48 and an end wall 49 which together define an interior 47. At one end, a projection in the form of a ledge 46 extends inwardly continuously around the inside of the cylindrical wall 48. The first column member 32 is in a lying down position, the longitudinal axis of the first member 32 being substantially horizontal.

The second column member 34 includes a hollow cylindrical wall 52 and an end wall 53 which together define an interior 55, with at one end a projection in the form of a ledge 54 extending inwardly continuously from the inside of the cylindrical wall 52 and a flange projection 50 extending outwardly continuously from the cylindrical wall 54.

The method includes the step of slideably locating the second column member 54 inside the first column member 32, so that the flange projections 50 of the second column member 34 seat against the ledge 46 of the first column member. With the second column member 34 within the first column member 32 a retaining collar 56 is positioned at the open end of the first column member 32, the retaining collar 56 permitting slideable movement of the second column member 34 relative to the first column member 32 but 1 5 preventing passage of the flange projection 50 of the second column member 34 therethrough.

The third column member 36 includes a hollow cylindrical wall 58 having at one end a flange projection 60 projecting outwardly continuously from the cylindrical wall 58 and at the other end an enlarged end 62. The third column member 36 is located within the second column member 34 so that the flange projection 60 of the third column member 36 seats against the ledge 54 of the second column member 34. With the third column member 36 located within the second column member 34, a retaining collar 64 is fixed to the second column member 34, the retaining collar 64 permitting sliding movement of the third column member 36 relative to the second column member 34, but preventing passage of the flange projection 60 therethrough. As shown in Figure 3C, at another location within the dry dock the housing 24 is mounted to the housing mounting 26.

The column 28 is sealed and buoyancy means in the form of buoyancy tanks 70 are then fitted to the column 28 and secured by means of securing members in the form of, for example, straps 72. The buoyancy means could also be provided either wholly or partly by air within the sealed column 28.

Water 42 is then introduced into the dry dock and the column 28 floated out of the dry dock.

Figures 4A and 4B show the base 30 which includes an upstanding wall part 31 and a flange part 37 extending from a lower part of the wall part 31.

The base 30 is formed, for example, in the dry dock on the floor 44. The base could be formed of concrete and could have the form of an egg box, defining a plurality of concave recesses 39 which are located on the upper side.

Buoyancy means in the form of buoyancy tanks or bags are fitted within the recesses 39 of the base 30 and the dry dock flooded to float the base 30 out of the dry dock. Alternatively, the recesses 39 could be filled with buoyancy material. Figure 5 shows the base 30 being positioned at an assembly position. In this example the buoyancy tanks are located within the socket 38 and the recesses 39. At the assembly position, the buoyancy of the buoyancy tanks is adjusted so that the base 30 is positioned on the bed 40 under the water 42 as shown by arrows A. If the bed 40 is considered unsuitable for supporting the base 30, or if the assembly position is to be used for the assembly of a number of columns, then suitable reinforcement of the bed 40 could be undertaken to improve the durability and stability of the bed 40. For example, a layer of suitable bedding material similar to that shown in Figs 9 and IOA with the reference numeral 76 could be provided. In another example, the bed 40 could be stabilized and/or reinforced by piles. The piles could be installed using existing offshore technology. After driving to the required depth the piles are cut off at a suitable level for the base to sit at the top ends of the piles. Alternatively a layer of suitable material or a suitable support cradle is provided between the top of the piles and the underside of the base. In another example, a purpose built receiving cradle or platform (not shown) could be provided to receive the base 40 at the assembly position.

As shown in Figure 6, the column 28 supported by the buoyancy tanks is floated into the vicinity of the base 30. The buoyancy of the buoyancy tanks 70 is adjusted so that one end of the column 28 sinks towards the socket 38 as indicated by arrows B in Figure 6, so that the socket 38 receives the said end of column 28, so that the column 28 is mounted to the base 30.

The square socket 38 and square end of column 28 permits correct alignment of the column 28 to the base 30, and helps prevent twist in use.

Alternatively, the end of column 28 could be circular or polygonal in sectional plan to make installation into the socket 38 easier.

With the column 28 mounted to the base 30, and the base 30 sifting on the bed 40 under the water 42, the housing 24 and the housing mounting 26 can be floated into the vicinity of the column 28. In one example, as shown in Figure 7, the position of the water surface 66 is such that the housing mounting 26 and the housing 24 can simply be floated into position on the enlarged end 62 of the column 28. Securing members 74 can be attached between the base 30 and the housing 24 and/or housing mounting 26 to control the positioning of the housing mounting 26 relative to the enlarged end 62, and the buoyancy of buoyancy tanks 71 supporting the housing 24 and housing mounting 26 can also be adjusted to control the positioning.

The wind turbine mounting 14, comprising the assembled housing mounting 26, column 28 and base 30, along with the housing 24 is then lifted by the addition of further buoyancy tanks 69, so that the assembled mounting 14 floats clear of the bed 40 as shown in Figure 8. The mounting 14 can then be towed to an installation position as shown in Figure 9, and the buoyancy tanks 69 adjusted to seat the mounting 14 on the bed 40. Prior to seating, a layer of suitable bedding material 76 such as a carpet of graded rock is formed on the bed 40.

In one example, the wind turbine assembly 10 is to be installed in a position in a sea, and the variation in the depth of the sea is utilized to aid the assembly. Thus, the appropriate depth of water 42 is chosen to facilitate the step of mounting the column 28 to the base 30, and the step of mounting the housing mounting 26 to the column 28. Thus in this embodiment the depth of water 42 at the assembly position is chosen to be deeper than the depth of water at the installation position to facilitate erection of the column 28 and assembly of the mounting 14.

Following positioning of the base 30 on the bed 40, further suitable material 76 such as graded rock is built up around the flange part 37 of the base 30 to form a bund. Settable material such as grout or concrete 78 is also located into the socket 38 between the first column member 32 and the base 30 to secure the column 28 within the base 30 as shown in Figure 1OA.

At this stage, with the column 28 in the retracted condition, the rotor structure 17 can be mounted to the shaft 22, by for example floating the rotor structure 17 into the vicinity of the column 28.

Figures IOA, lOB and 1OC show stages in the extension of the second and third column members 34, 36 from the first column member 32.

Figures 11, 12A, 12B, 12C and 12D show stages in a method of extending the telescopic column 28. In an initial condition as shown in Fig. 11, the flange projection 50 of the second column member 34 is seated on the ledge 46 of the first column member 32, and the flange projection 60 of the third column member 36 is seated on the ledge 54 of the second column member 34. The ledge 46 defines a plurality of recesses in which a plurality of hydraulic jacks 80 are positioned below the flange projection 50 of the second column member 34, and the hydraulic jacks 80 actuated to lift the second column member 34 upwardly. A plurality of support members in the form of wall members 82 are then located between the ledge 46 of the first column member 32 and the flange projection 50 of the second column member 34 as shown in Figure 12A. The jacks 80 and wall members 82 are located sequentially alternately around the inside of the cylindrical wall 48.

In the jacking and supporting operation, operatives 83 stand on a suspended work platform 85 which is supported by cables 87 connected to the first and second column members 34, 36 and winches 89. The work platform 85 rises at the same rate as the top of the liner wall as it is constructed and so maintains access to the top of the wall for the operatives.

The wall members 82 could be stored in the second column member 36 during delivery and are carried to the operatives via a conveyor system 95.

When lifting of the second column member 36 is finished the jacks 80 are moved into recesses 91 defined by the inwardly projecting ledge 54 for lifting the third column member.

Figures 12A to 12D schematically show one example of a process of sequentially jacking and supporting the second column member 34 to extend 1 5 the telescopic column 28. In Figure 12A, the jacks 80 are extended, and the wall members 82 positioned between the first and second column members 32, 34. The jacks 80 are retracted, and as shown in Figure 12B, one wall member 82 positioned beneath each of the jacks 80. The jacks 80 are then extended as shown in Figure 12C, and another wall member 82 placed between the wall members 82 already in place and the second column member 34. The jacks 80 are then again retracted, another wall member 82 placed beneath each jack 80 as shown in Figure 12D, and the process repeated. Thus, the step of supporting includes building an inner structure which in one example is in the form of a lining wall.

In one example, each jack 80 has a lifting capacity of 300 tonnes with a lift of approximately Im. The jacks 80 could be powered screw jacks. The jacks 80 could each be independently controlled to permit adjustment of the relative alignment of the column members 32, 34, 36.

Figures 13 and 14 show a wall member 82. The wall member 82 includes a pair of spaced, substantially planar flange members 88 with a web member 90 extending therebetween, the web member 90 having a "T" shape in plan as shown in Figure 13, each of the free ends of the "T" including an angled part for extra strength.

Each wall member 82 includes substantially vertical connectors 94 in the form of plates defining holes through which, in use, fasteners such as bolts can be located into ties 86 positioned in the walls 84 of the column members, and wall member connectors 92 for connecting adjacent wall members 82 together when in situ. In this way an inner liner wall is constructed to support the column members above.

The jacking and wall building operation continues until the second column member 34 is fully extended, with the flange projection 50 located against the underside of the retaining collar 56 of the first column member 32.

Support means in the form of raking members 96 as shown in Figures lOB, bC are then located between the cylinder walls 48 of the first column member 32 and the underside of the flange projection 50 of the second column member 34. The raking members 96 are angled, and seat in recesses (not shown) defined in the column walls 48. The column walls 48 are thickened in the vicinity of the recess to form a reinforcing collar 98.

When the raking members 96 are securely in position, the joint between the first and second column members 32, 34 is grouted up. Jacking and wall building for supporting the third column member 36 can then take place, and this proceeds in a similar manner to that described for the second column member 34. When the third column member 36 is fully extended so that the flange projection 60 of the third column member abuts the underside of the retaining collar 64 of the second column member 34, raking members 96 are again installed to retain the third column member 36 in the extended position.

The jacking and wall building operation is now complete, and the wall members 82 can be removed from the interior of the column 28 for re-use.

It will be noted that the method of extending the telescopic column 28 described takes place wholly within the interiors 47, 55 of the first and second column members 32, 34. Thus the operation is less susceptible to external environmental conditions such as weather and sea conditions than conventional methods. The method is failsafe.

With the column 28 fully extended, the blade members 18 can be mounted to the rotor structure 17, the blade members 18 being winched into position.

There is thus described a column, and a method of assembly of a column, which permits the column to be of a relatively large size, but does not require the use of large cranes for assembly and installation. Such cranes limit the height of column which can be erected, are expensive, and can only be used in certain weather conditions. If the wind turbine assembly needs to be re-sited, or decommissioned, then the wind turbine assembly 10 could be disassembled by reversing the steps described above.

Figures 19 to 21 show another example of buoyancy means for moving the assembled wind turbine mounting 14, in the form of a flotation collar 169 which extends around the column 28. The collar 169 includes a plurality of water ballast tanks 172 (only a few of which are labeled) the buoyancy of which are adjustable. The collar 169 includes a removable part 170 to permit releasable engagement with the column 28. In another example, the flotation collar 169 is U shaped in plan with no removable part.

Various other modifications could be made without departing from the scope of the invention. The column could comprise any suitable number of column members and could include only one column member. The column could be erected in any suitable manner, and could be of any suitable shape and size and formed of any suitable material. The base could be of any suitable size and shape, and the socket and corresponding shaped part of the column could be of any suitable size and shape. The column could be of a different shape to the socket. The buoyancy means could be of any suitable type. Any suitable method of extendin g the members of the column could be employed. Any suitable method of jacking and any suitable number and types of jacks could be employed. The wall members could be of any suitable size and design. The wind turbine assembly could include any suitable number of blade members, which could be of any suitable size and shape, and could be fixed to the shaft in any suitable manner. The rotor structure could be of any suitable type, and may not be present. The blade members could be mounted directly to the shaft, or could be mounted to a hub.

Instead of the raking struts, a joint could be formed between the column members in any suitable way. For example, resin could be used to form the joint, or steel reinforced concrete, or post tensioned cables.

Figure 15 is a detail of the top of the wind turbine assembly 10, showing the housing 24 and the housing mounting 26. The housing mounting 26 includes a mounting flange 100. The housing 24 includes a housing body 25 and a housing flange 102 which is discontinuous and extends downwardly from the body 25 to engage the mounting flange 100. The assembly 10 includes friction reducing means which are provided between the housing 24 and the housing mounting 26, and in one example could include roller bearings 112 located between the underside of the housing body 25 and the upper surface of the mounting flange 100, and roller bearings 114 located between the undersurface of the mounting flange 100 and an upper surface of the housing flange 102. The friction reducing means could include annular steel tracks in or on which the roller bearings 112, 114 run.

In plan, the flanges 100, 102, are annular, and the arrangement of the friction reducing means and the interlocking flanges 100, 102 permits rotation of the wind turbine 12 relative to the wind turbine mounting 14, while permitting the transfer of horizontal and vertical forces, shears and overturning moments therebetween.

A projection 106 extends downwardly from the housing body 25 and is received within a socket 104 defined by the housing mounting 26. The housing mounting 26 includes friction reducing means in the form of bearings 116, which could be in the form of rollers between the horizontal and vertical surfaces of the projection 106 and the housing mounting 26, which resist sideways movement in the horizontal plane of the housing 25 relative to the housing mounting 26, and support vertical loads.

Alternatively, the projection 106 could extend further downwardly to form a vertical shaft supported by a plurality of horizontal bearings within mounting 26. This arrangement of shaft and bearings could transfer horizontal and vertical forces, shears and overturning movements between the housing 25 and the housing mounting 26 while permitting rotation between the wind turbine 12 and the turbine mounting 14. In one example, the horizontal flanges 100 and 102 are not provided.

The wind turbine 12 includes a plurality of spaced shaft bearings 108 which are located within the housing body 25, and which rotatably mount the shaft 22. Conventionally, wind turbines have only one set of shaft bearings which are subject to a high degree of wear. The relatively large housing body permits two or more spaced bearings 108, which better transmit forces from the drive means to the column 28. As shown in Figure 15, the spacing of the bearings 108 corresponds approximately to the diameter of the column 28 to maximize the forces that can be transferred from the drive means to the column 28.

The wind turbine 12 includes a generator arrangement in the form of a plurality of generators 110 which are driven by the shaft 22. The generators are located side by side along the shaft 22 within the housing body 25.

The wind turbine assembly 10 also includes housing drive means (not shown) to drive the rotation of the wind turbine 12 relative to the wind turbine mounting 14.

The wind turbine 12 includes balance means in the form of a balance tank 118 which is arranged to permit adjustment of the centre of gravity of the housing 24 over the column 28 to facilitate rotation of the housing 24 relative to the housing mounting 26. The tank 118 could include a fixed weight such as concrete, and adjustable water ballast to counterbalance the forces imposed by the drive means which vary according to wind speed.

The wind turbine 12 includes a passive-dynamic stabilizer 111 which is located within the housing mounting 26, and which is arranged to control the resonant sway of the wind turbine assembly 10.

In one example of the wind turbine assembly, the diameter of the shaft 22 is relatively large in comparison with conventional wind turbine shafts, permitting the blade members 18 to be directly mounted to the shaft 22. In another example, the carrier members 20 are directly mounted to the shaft 22.

The shaft 22 runs through the housing 24, and the generators 110 are mounted to the shaft 22, so that there is no gear box between the shaft 22 to which the blade members 18 or carrier members 20 are mounted and the shaft 22 driving the generators 110. The direct drive is cheaper, more efficient and reduces maintenance costs.

The direct mounting of the blade or carrier members 18, 20 to the shaft 22 means that a hub to mount the blade or carrier members 18, 20 to the shaft 22 is not required. Hubs are typically formed by casting, and such castings are complex, difficult and time consuming to manufacture, and expensive.

The relatively large size of the wind turbine assembly 10 and its components provides a number of advantages. Storage and accommodation could be provided in the column 28, and the column 28 could also provide access internally to the housing mounting 26 and housing 24. Thus, exterior access to the housing 24 or housing mounting 26, which could be hazardous, is not required. Similarly, the large diameter shaft 22 could also include access passages permitting in situ maintenance of, for example, blade mountings and blade pitch controllers located inside the shaft 22. The housing mounting 26 and housing 24 could also be relatively large, permitting larger generator arrangements which could include new types of generators including cryogenic or super cooled generators. The use of large structures thus reduces maintenance costs.

Various other modifications could be made without departing from the scope of the invention. The wind turbine 12 and the wind turbine mounting 14 could be formed of any suitable materials. The wind turbine 12 could include any suitable number of blade or blade and carrier members, which could be mounted to the shaft 22 in any suitable manner. The wind turbine 12 could include any suitable number of generators 110 and bearings 108 which could be arranged in any suitable manner. In one example, a plurality of generators could be arranged on a plurality of concentric drive shafts, and the generators could be arranged end to end. The housing mounting 26 could be of any suitable size and shape, and could mount the housing 24 in any suitable manner.

1 5 The wind turbine assembly of the present invention and the method of assembly of the wind turbine assembly permits the construction of much larger wind turbines than heretofore have been possible. Previously, wind turbine assemblies have been limited in size by the capacity of floating cranes and jack up barges available for erection of the column. Thus, the present limit for the height above sea level of wind turbine assemblies is approximately I 20m. The method of assembly described above permits the size of the wind turbine mounting and the wind turbine mounted to the mounting to be increased. Hence the method permits wind turbine assemblies to be constructed of more than 120m height above sea. level.

In one example, each column member could be up to 70 metres in length and have a maximum diameter of 20 metres. Such a column member is likely to have a weight, when formed in reinforced concrete, of approximately 2000 to 4000 tonnes. With the housing and the housing mounting, such column members would permit a shaft height above sea bed or ground level of up to approximately 200m. Higher wind turbines also benefit from stronger, more consistent wind speeds at the higher level with fewer surface effects. The use of concrete allows massive, economical structures with a long design life, for example of 100 years or more, reducing the capital cost per unit energy generated.

The length of the blade members is limited by the strength of available economic materials, so that even if the blade members are mounted to a rotor structure 17 as described above, the maximum diameter of the swept area 68 is approximately 250 metres diameter. Such a swept area corresponds to a potential maximum wind turbine output of 25 to 30 megawatts, for example, in the North Sea, which is considerably higher than the output of conventional wind turbines. Blade or blade and carrier members of total length 125m would require a shaft height above sea level, assuming 35 metres of clearance between the blade member tip and sea level, of 160 metres.

Assuming a sea depth of 40 metres and 5 metres of contingency for tidal and weather effects, the required height of the shaft 22 from the sea bed 40 is 205 metres. The column and the method of assembly of the column described thus allows the swept area and hence the generating capacity to be maximized.

One of the most suitable areas for the location of wind turbines is an area extending north east of Grimsby into the North Sea. In this area, wind speeds are relatively high, having annual mean wind speeds at 50 metres above ground level in the open sea of more than 9 rn/s and providing a wind energy resource of more than 800 W/m2. In this area, the sea depth varies between 16 and 80m. The greatest depth, 80 m, is located in an area known as Skate Hole" which is relatively close to the coast. In the above described method of assembly therefore, the columns could be formed in a dry dock on the coast, each column member being in the region of 70 metres in length, the column then floated out to Skate Hole for assembly with the base, and then further floated into the installation position in a depth, for example, of 40 metres, for example, on Dogger Bank.

Wind turbine assemblies in the North Sea have to be designed to withstand hurricane force winds. Such winds will require the column to have a large spread footing, such that the base will be in the region of 60 to 70 metres square in plan.

Each column member, the base, the housing and the housing mounting are designed to float in approximately 3.5 metres depth of water with buoyancy aids, so that construction can take place in conventionally operated dry docks, which are flooded by a high tide.

In the method of erection of the wind turbine mounting described above, the column 28 is mounted to the base 30 in a relatively deep depth of water, and when the column 28 is mounted to the base, the assembled column and base is then floated to the installation position, in a shallower depth of water.

The proposed apparatus and methods enable heavy components to be assembled and delivered using buoyancy methods that effectively render the components weightless and provide the required forces. The proposed apparatus and methods enable the column and base to be effectively connected together under water using a simple peg in a hole' arrangement.

Figures 16 to 18 show another method of assembly of another wind turbine mounting 140, the wind turbine mounting 140 including a column 28 and a base 130, the method permitting the mounting of the column 28 to the base 130 in a relatively shallow depth of water, so that mounting of the column 28 to the base 130 can take place at the installation position.

Many features of the wind turbine mounting 140 of Figures 16 to 18 are the same as those previously described for the wind turbine mounting of Figures 1 to 15. Where features are the same or similar, the same reference numerals have been used, and these features will not be described again for the sake of brevity.

The base 130 is similar to the base 30 previously described, except that the base 130 is arranged to permit the column 28 to be inserted into the socket 38 at an oblique angle. Thus, some of the walls defining the socket 38 and the recesses 39 are missing, the missing walls 41 being denoted by dotted lines in Figure 16A. Close to the position of one of the missing walls the base 130 includes locating means in the form of an upstanding toe projection 75. One of the side walls of the base 130 is reduced in height relative to the other side walls to form a part wall 43.

As shown in Figure 16A, the base 130 is positioned on a bed of suitable material 76 such as a carpet of graded rock on the seabed 40 under the water 42. The column 28 is floated into the vicinity of the base 130, towards buoyancy means in the form of an annular flotation tank 171. The column 28 locates through the annular flotation tank 171.

The buoyancy of the column 28 is then adjusted to sink the column 28 to the position shown in Figure 16B, in which the column 28 is close to or is resting upon the part wall 43, one end of the column 28 being within or close 1 5 to the socket 38. A tether 73 is positioned between the base 130 and the column 28 for security.

Referring to Figure 16C, the buoyancy of the column 28 is again adjusted, so that the column 28 locates against the toe projection 75 and rotates into a vertical position in the socket 38 as shown in Figure 16D.

Stabilizing cables could be attached between the top of the column 28 and tugs (not shown) to control the movement of the column 28 once it passes the pivot point moving into the socket 38.

Referring to Figure 16E, the buoyancy of the column 28 is again adjusted to lift the column 28, to permit the insertion of packer members 180 underneath the column 28, the packer members 180 providing a safe working height for divers between the column 28 and the base 130.

Referring to Figure 16F, jacks 181 are positioned between the column 28 and the base 130, which are used to adjust the alignment of the column 28, and the packer members 180 are removed.

Referring to Figure 16G, the wind turbine mounting 140 includes a housing mounting 25 which is assembled to a housing 24 and floated into position near to the erected column 28 and base 130 by buoyancy means in the form of a buoyancy tank 71. The wind turbine mounting 140 in this embodiment also includes a fourth column member 120 which is in the form of a hollow cylinder. For flotation purposes, the fourth member 120 is provided with sealed end walls and floated into the vicinity of the base 130 and column 28.

Buoyancy means in the form of a lifting tank 122 is located adjacent to the column 28, the lifting tank 122 being receivable within one of the recesses 39 defined by the base 130. As shown in Figure 16G, the fourth column member 120 is positioned above the lifting tank 122, and the buoyancy of the fourth member 120 adjusted so that it seats on the lifting tank 122.

Similarly, as shown in Figure 16H, the housing 24 and housing mounting 25 are positioned adjacent to the column 28, and the buoyancy of the buoyancy tank 71 adjusted so that the housing mounting 25 seats on the fourth column member 120.

The buoyancy tanks 71 which are used to provided buoyancy for the housing 24 and housing mounting 25 are arranged to permit the positioning of the housing 24 and housing mounting 25 adjacent to the column 28. Once the housing 24 and housing mounting 25 are in position, the buoyancy tanks 71 are removed.

In the position shown in Figure 161, a frame structure 124 as shown in Figures 17 and 18 is positioned between and around the column 28, the base 130, the housing 24, the housing mounting 25, the fourth column member 120 and the lifting tank 122.

Figures 17 and 18 show the frame structure 124 in more detail. The frame structure 124 includes a plurality of buoyancy tanks 138 to permit the frame structure 124 to be floated into position, a pair of spaced, parallel transfer members 126 which extend horizontally onto the top of the column 28 and two spaced pairs of spaced support arms 128 which extend upwardly from a cradle 134 which is movable along the transfer members 126. The frame structure 124 also includes roller guides 132. The frame structure 124 is fixed onto the base 130.

The lifting operation proceeds as follows. The buoyancy of the fourth column member 120 and the lifting tank 122 is adjusted to lift the housing 24 and housing mounting 25 upwardly relative to the column 28. The roller guides 132 and the frame structure 124 guide the upward movement. At or towards the limit of the upward movement, when the buoyancy lift is reduced as the lifting tank 122 approaches the water surface 66, the support arms 128 engage complementary formations formed on the housing 124 or housing mounting 25 to hold and support the weight of the housing 24, the housing mounting 25, and the fourth column member 120. At this stage, the joint between the fourth column member 120 and the housing mounting 25 can be made. In one example, the joint could comprise a plurality of reinforced concrete stitches extending between the housing mounting 25 and the fourth column member 120.

The lifting tank 122 is then detached from the fourth column member 120 and lowered into the recess 39.

Referring to Figure 16J, a lift spacer 136 is inserted between the lifting tank 122 and the fourth column member 120. The lift spacer 136 could be in the form of an open steel frame, which serves to space the lifting tank 122 from the water surface 66. The lift spacer 136 includes buoyancy means for delivery and lifting. The lifting operation is then repeated, until the bottom of the fourth column member 120 is above or level with the top of the column 28, as shown in Figure 16K.

The lifting operation thus includes sequentially lifting, holding and packing (or spacing), and then lifting again. If necessary these steps can also be repeated. At this stage, the lifting operation can be repeated if further additional column members are required.

Referring again to Figure 16K, the support arms 128 engage the fourth column member 120 to support the weight of the fourth column member 120, the housing mounting 25 and the housing 24. The lift spacer 136 is detached from the fourth column member 120. The cradle 134 is then moved across the transfer members 126 as indicated by arrow B to position the fourth column member 120, the housing mounting 25 and the housing 24 on top of the column 28.

Once the fourth column member 120, the housing mounting 25 and the housing 24 are in position, the frame structure 124 can be removed and the fourth column member 120 fixed to the third column member 36 by, for example, concrete stitching as previously described.

The frame structure 124 thus provides guidance, support and holding means during the assembly.

The wind turbine mounting 140 is now as shown in Figure 16L. Final adjustments can be made by the jacks 181 to the alignment of the column 28.

The missing walls 41 can be constructed and the settable material 76 located between the base 130 and the column 28 in the socket 38. The jacks 181 are left permanently in position between the base 130 and the column 28.

In another method the flat jacks 181 could be omitted and a layer of self leveling grout or delayed setting concrete in bags could be laid to give a level and horizontal surface, which provides a foundation for the column. If the column does not have a facility for adjusting verticality, then the verticality of the column is dependent on the horizontality of the foundation surface.

At this stage also the rotor structure 17 could be fixed to the shaft 22, avoiding the requirement for a crane to lift the rotor structure 17 into position when the telescopic cotumn 28 has been extended.

The wind turbine mounting 140 is now ready for the extension of the column members as previously described.

The feature of the base 130 having missing walls 41 helps to reduce the depth of water required for erecting the column 28. For example, the socket 38 could have a depth of approximately 18 metres, so that by providing missing walls 41, the depth of water required for manoeuvring the column 28 is reduced by approximately 18 metres. The provision of the lifting tank 122, the lift spacer 136 and the frame structure 124 further permit the depth of the water to be reduced, since this method provides a way in which the buoyancy of the water 42 can be used to locate items onto the column 28 which is projecting out of the water 42. Thus the water depth can be further reduced, so that the wind turbine assemblies of the present invention can be assembled at the installation position.

The method also permits the use of the fourth column member and 1 5 possibly further additional column members, which in turn permits a reduction in the length required of the other column members, further reducing the depth of water required.

Various other modifications could be made without departing from the scope of this embodiment of the invention. The buoyancy means could be of any suitable type. The frame structure could be of any suitable design, formed of any suitable materials. The base and in particular the missing walls could be different to that described. The location means could be different.

Figures 22 and 23 show another method of assembly of another wind turbine mounting 240, the wind turbine mounting 240 including a column 228 and a base 230 installed in a shallow sea 42 on a sea bed 40.

The method uses many of the features already described but does not feature a telescopic column nor internal column jacking.

The method is as follows as shown in Figure 22.

Figure 22 shows three locations at and adjacent to a wind farm installation site in shallow water (for example 20m deep) indicated generally by reference number 250. Adjacent to the site 250 (up to for example within km) there could be locations where the water is of medium depth (for example 40m) indicated by reference number 251 and of greater depth (for example lOOm) indicated by reference number 252.

Referring to Figure 22A, the method starts at the medium depth site 251 where a substantially level horizontal working platform 253 is constructed on the seabed 40 using settable material such as a graded rock carpet with a concrete topping layer. (For this method the concrete topping layer is added because there is less opportunity for adjusting the verticality of the column 228 during installation and so a substantially level and horizontal work platform is required).

The base 230 is delivered to the medium depth site 251 and installed on the work platform 253 using methods already described.

A first column member 254 with sealed ends is then delivered and using buoyancy means in the form of a flotation tank 255 is mounted to the base 230 using methods already described.

The first column member 254 is then permanently fixed in the base 230 using a settable material such as grout or concrete 256 as described previously.

Referring to Figure 22B, using flotation methods the first column member 254 and the base 230 are moved to the greater depth site 252 where the assembly is placed on a prepared base 257. The base 257 is a substantially flat horizontal work platform constructed from suitable material such as a graded rock carpet.

Buoyancy means in the form of a flotation and stability collar 261 is then installed at the top of the first column member 254. As shown in Figure 23A, the collar 261 includes a plurality of water ballast tanks 266, only a few of which are labeled, the buoyancy of which are adjustable.

A second column member 258 and a housing 259 are then delivered and using buoyancy means in the form of a flotation tank 260 are installed on top of the first column member 254. The first and second column members 254, 258 are permanently joined using, for example, steel reinforced concrete.

Using flotation methods the assembled wind turbine mounting 240 is then moved from the greater depth site 252 and put back onto work platform 253 at the medium depth site 251.

The flotation and stability collar 261 is adjusted so that it floats freely around the first column member 254.

The flotation and stability collar 261 incorporates clamping means (not shown) that can be operated and released to clamp the collar 261 to the first column member 254 when required.

The purpose of the flotation and stability collar 261 is to stabilize the wind turbine mounting 240 when it is being maneuvered in shallow water between the medium depth site 251 and final installation at the shallow depth site 250. Within the deeper water between the greater and the medium depth sites 252, 251 the wind turbine mounting 240 will float stably without the collar 261 being operational which is carried in a temporary location at the top of the first column member 254.

The wind turbine mounting 240 is now re-floated off work platform 253 and moved from the medium depth site 251 to the permanent installation location at the shallow site 250.

During the transfer from the medium depth site 251 to the shallow site 250 the flotation and stability collar 261 is clamped, unclamped and re-clamped sequentially at intervals so that as the water depth reduces and the amount of flotation is adjusted to reduce the draft of the floating mounting 240 the collar 261 moves lower down the first column member 254 so that the collar 261 remains floating in the sea.

When the mounting 240 is close to the permanent installation shallow site 250 and there is reduced clearance between the underside of the base 230 and the seabed 40, the stability collar 261 could be fixed to the top of the base 230 and also connected by ties 262 to the base 230. This is to give greater stabilizing effects.

During the various transfers between the sites 250, 251, 252 the majority of the required buoyancy is provided by using the internal flotation capacity of the first column member 254 and the base 230 by adjusting the amount of water ballast within these components.

At the shallow site 250 the mounting 240 is lowered onto a prepared bed formed from suitable materials such as a graded rock carpet laid on sea bed as described in previous methods.

1 5 When the mounting 240 has been installed the flotation and stability collar 261 is removed. The collar 261 includes a removable part 263 to facilitate removal. Alternatively the flotation and stability collar 261 could be U shaped without a removable part.

The blade members 264 are then installed to complete the assembly of the wind turbine assembly for example by winching.

The first and second column members 254, 258 could be formed of any suitable material, and could be formed of steel.

Any suitable method of forming the joint between the column members 254, 258 could be used, for example bolting, resins or adhesive materials.

This embodiment of the invention provides a wind turbine mounting erected without the use of cranes or jacking.

Figure 24 shows another method of assembling another mounting 240.

Referring to Figure 24, prior to fitting the flotation and stability collar 261 to the first column member 254 mounted to base 230, the second column member 258 is placed on a temporary support plinth 304 which is temporarily mounted to the base 230 adjacent the first column member 254, the position being as indicated by the letter X in Figure 24.

The height of the support ptinth 304 is adjusted so that a housing 305 and a housing mounting 306 supported by buoyancy means in the form of a flotation and delivery tank 307, when delivered to the ass embly site, which could for example be the deep water site 252, can pass over the top of the second column member 258 when the second column member 258 is standing on the support plinth 304.

The housing 305 and the housing mounting 306 supported by the flotation tank 307 are lowered to sit on top of the second column member 258.

1 5 The housing mounting 306 is then permanently connected to the top of the second column member 258. The flotation tank 307 is then moved down the second column member 258 to an intermediate position labeled A in Figure 24.

The second column member 258 is partially filled with water ballast 308, and by using the flotation tank 307 in the intermediate position A the second column member 258 including the housing 305 and the housing mounting 306 are moved to one side, off the plinth 304 to position Y as shown in Figure 24 to allow the flotation and stability collar 261 to be fitted over the first column member 254.

By adjusting the water ballast 308 within the second column member 258 and using flotation methods, the second column member 258, the housing 305 and the housing mounting 306 are then raised relative to the surface 66 of the sea and positioned on top of the first column member 254.

The bottom of the second column member 258 is then permanently connected to the top of the first column member 254. The flotation tank 307 is now removed for reuse.

By this method the housing 305 is mounted to the top of the second column member 258 prior to the assembled wind turbine mounting 240 and housing 305 being moved by flotation methods to the wind turbine final installation site.

If a rotor structure is required to be fitted to the housing 305 then the rotor structure could be fitted using flotation methods for delivery and winching from the housing 305 at this stage.

A locating means in the format of a temporary bracket projection 311 could be provided fixed to the side of the second column mounting 258 to be used as a pivot point for "upending" the rotor structure when it is being winched up to be fixed to the housing 35.

In certain circumstances, such as when the seabed is relatively soft, the methods of the present invention could include the step of providing piles into the seabed. At both the assembly site and the final installation (wind farm) site, some or all of the piles could be provided before location of the base 30 on to the seabed, in which case the piles could form locating or guide means.

At the final installation (wind farm) site as shown in Figs 25 -28, a base 330 includes a base wall 332 which defines a plurality of holes 334 therethrough into the recesses 39. The holes 334 receive piles 336 driven into the seabed 40. Exposed extending steel reinforcement 340 is provided around the holes 334 to connect with pile caps 338 fitted over the piles 336 to connect the piles 336 to the base wall 332.

If the base 330 is to be supported by piles at the final installation site (wind farm) then the carpet of material 76 is not provided, Instead the base 330 sits on the sea bed 40.

A piling frame (not shown) is mounted on the base 330 and the piles 336 are positioned and driven through the holes 334 provided in the base 330. The piles 336 could be vertical as shown in Figs 26 and 27, or could be inclined as shown in Fig 28 to suit the applied loads.

After driving to the required length/depth the piles 336 are cut off to protrude above the base wall 332. The piles 336 are then connected to the base wall 332 using upside down precast concrete thimble caps 338 fitted over the piles 336. Extending exposed steel reinforcement 340 inside each pile cap 338 laps with steel reinforcement 340 extending from the base wall 332. The inside of the thimble pile cap 338 is then filled with grout to form the connection.

In another method piling required to support the wind turbine assembly at the final installation (wind farm) site can be installed using existing offshore technology in advance of the delivery and installation of the wind turbine assembly.

In this method piling is driven into the sea bed and cut off at a suitable level to receive the base of the wind turbine assembly.

The base can sit on top of the ends of the piles or the piles can pass through holes in the floor slab of the base. In both cases the piles are rigidly connected to the base using suitable sub sea connection methods.

In another method, the base 30 as shown in Figs 4 -8 is not lowered to rest on the sea bed 40 but is held at an intermediate level in the sea 42 to receive the column 28. The base 30 is held at the required level by water thrusters (not shown) connected to the base 30 or by cables (not shown) connected to the base 30 and to vessels (not shown) on the surface of the sea. The vessels adjust the tension in the cables to control the depth of the base 30 or by any other suitable means.

Figs 29 -35 show an example of a support structure 480 for use in the step of extending the telescopic column 28 in another method of assembly of a mounting for a wind turbine. The support structure 480 includes a plurality of support members 482, each support member 482 including a body 483 in the form of a hollow cylinder defining an interior 484, each support member 482 including a lip 486 projecting from one end which is receivable within the interior 484 of an adjacent support member 482, permitting stacking of the support members 482 to form a column 496. The support members 482 could be formed of steel tube.

Each support structure 480 comprises three columns 496 in a triangular arrangement in plan. Each support member 482 defines one or more slots 488 which permit bracing members 490 to extend between adjacent support members 482, locking the support members 482 in position together. As shown in Figs 34 to 35, lateral bracing members 490A extend between adjacent columns 496 to form a substantially continuous bracing ring.

Restraining members 492 in the form of straps or ties are installed at vertical intervals, extending from pairs of spaced connectors 494 in the column wall 48 around the support structure 480. A plurality of support structures 480 are formed at spaced intervals around the inside of the cylindrical wall 48 to form a lining wall or structure as shown in Figs 34 and 35. The lateral bracing members 490A, cross bracing members 490B and restraining members 492 are spaced apart at vertical intervals as shown in Fig 34.

Each support member 482 could be sized so that it can be lifted into place by one man. For example, the size could be arranged so that the support member 482 has a weight of not more than 25kg. The body 483 could for example be a tube section of 300mm diameter and 250mm length with a wall thickness of 8mm, with a weight of 20kg.

Three such support members 482 fixed together in a triangular plan would carry a vertical load of 400 tons which would be suitable for forming the inner lining wall used to erect a column suitable for a 20 MW turbine.

In another method, the stability of the wind turbine assembly 10 when being moved into shallow water could be enhanced by allowing the underside of the base 30 of the wind turbine assembly 10 to partially rest on the sea bed 40 while still being moved forwards or sideways. This will stop the wind turbine assembly 10 from rolling over (capsizing). Fig 34 shows another base 530 in which the bottom edges of the sides of the base 530 are formed with a chamfer 500 or a radius 510 to form a sloping or a curved surface respectively. This prevents the bottom edges of the sides of the base 530 or the bottom corners of the base 530 digging into the sea bed and becoming stuck and so preventing forwards or sideways movement of the wind turbine assembly 10.

The sloping or curved profiles could be formed in the original construction of the base 530 or by fixing suitably shaped fairings to the base 0 530.

One of the features of the methods described for installing and erecting wind turbine assemblies is that the methods do not require the use of cranes.

However, if the height and weight of the wind turbine assembly is within the reach and capacity of a suitable crane or cranes then the design of components and methods described here are suitable for erection using cranes.

In one method a wind turbine assembly 10 including a first column member 32 and second and/or third column members 34, 36 and a turbine housing 24 could be installed in a base 30 using the methods described.

The housing 24 and second and/or third members 34, 36 could then be pulled up (extended) to the required height using a suitable crane or cranes.

To reduce the weight to be lifted the second and/or third column members 34, 36 and the housing 24 could be made of steel.

In one example, a floating crane with a reach of 120m above sea level could extend a column 28 and housing 24 to a height of lOOm above sea level. This height of column would be suitable for a wind turbine with a generating capacity of 6MW approximately.

As already described the use of cranes becomes increasingly difficult with increasing column height and would not be possible for the 20MW and greater generating capacities envisaged by this application.

The invention provides any suitable combination of features of the apparatus and method steps of any of the embodiments described.

The methods of assembly and erection disclosed could be used to assemble or erect a variety of structures, and are not limited to wind turbine assemblies.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Claims 1. A mounting on which a wind turbine is mountable, the mounting including a column.
2. A mounting according to claim 1, in which the mounting includes a base, and the column is mountable to the base.
3. A mounting according to any of the preceding claims, in which the base includes an engaging formation, for engaging the column.
4. A mounting according to claim 3, in which the engaging formation is in the form of a socket, which is defined by the base, in which at least part of the column is receivable.
5. A mounting according to claim 4, in which the socket is polygonal in plan, and the part of the column receivable within the socket is shaped to correspond with the shape of the socket.
6. A mounting according to claim 5, in which the socket is square in plan.
7. A mounting according to any of the preceding claims, in which the column includes a plurality of members.
8. A mounting according to claim 7, in which the column includes a first member and a second member.
9. A mounting according to claim 8, in which in use the second member is telescopically connected to the first member.
10. A mounting according to claim 9, in which the second member projects from the first member.
11. A mounting according to any of claims 8 to 10, in which the column includes a third member.
12. A mounting according to claim 11, in which the third member is telescopically connected to the second member.
13. A mounting according to claim 12, in which the third member projects from the second member.
14. A mounting according to any of the preceding claims, in which the column is formed of concrete.
15. A mounting according to any of the preceding claims, in which the base is located under water.
16. A mounting according to claim 15, in which the column is mounted to the base by floating the column into the vicinity of the base, and at least partially sinking the column.
17. A wind turbine assembly, the wind turbine assembly including a wind turbine mounting on which a wind turbine is mountable, the mounting including a column.
18. An assembly according to claim 17, in which the mounting is as defined in any of claims 1 to 16.
19. An assembly according to claims 17 or 18, in which the assembly includes a wind turbine.
20. A wind turbine assembly, the wind turbine assembly including a wind turbine, the wind turbine being mountable on a mounting.
21. An assembly according to claim 20, in which the mounting is as defined in any of claims ito 16.
22. A wind turbine assembly according to any of claims 19 to 21, in which the wind turbine includes a housing, drive means, and a shaft, the drive means being mounted to the shaft, the shaft mounted within the housing, the turbine including a generator arrangement, and being arranged so that the drive means cause the shaft to rotate, and the rotating shaft causes the generator arrangement to generate electricity.
23. A wind turbine assembly according to claim 22, in which the generator 1 5 arrangement includes a plurality of generators.
24. A wind turbine assembly according to claim 23, in which the generators are mounted along the shaft.
25. A wind turbine assembly according to claim 24, in which the generators are mounted side by side.
26. A wind turbine assembly according to any of claims 22 to 25, in which the drive means include a plurality of blade members, each of which is mounted directly to the shaft.
27. A wind turbine assembly according to any of claims 22 to 25, in which the drive means include a hub which is mounted to the shaft and a plurality of blade members which are mounted to the hub.
28. A wind turbine assembly according to any of claims 22 to 25, in which the wind turbine includes a rotor structure which is mounted to the shaft and a plurality of blade members which are mounted to the rotor structure, and the rotor structure includes a plurality of carrier members.
29. A wind turbine assembly according to any of claims 22 to 28, in which the wind turbine includes a plurality of spaced shaft mountings, each of which includes bearings to permit rotation of the shaft.
30. A wind turbine assembly according to any of claims 22 to 29 when dependent on claims 18 or 21 or any claim dependent thereon, in which the wind turbine assembly includes a housing mounting for rotatably mounting the housing to the column.
31. A wind turbine assembly according to claim 30, in which the wind turbine assembly includes housing drive means for rotating the housing relative to the column.
32. A method of assembly of a mounting for a wind turbine, the mounting including a column, the method including a step of erecting the column.
33. A method according to claim 32, in which the mounting includes a base, and the step includes positioning the base under water.
34. A method according to claim 33, in which the erection step includes floating the column into the vicinity of the base.
35. A method according to claim 34, in which the erection step includes at least partially sinking the column to mount the column to the base.
36. A method according to claim 35, in which the method includes a step of lifting the assembled column and base to reposition the assembled column and base at another location.
37. A method according to claim 36, in which the lifting is by buoyancy means.
38. A method according to any of claims 32 to 37, in which the column includes a first member and a second member which are telescopically connected, and the erection step includes a step of extending the second member from a retracted position substantially within the first member to an extended position.
39. A method according to claim 38, in which the extending step includes the steps of sequentially jacking and supporting the second member from the retracted position to the extended position, which steps may be repeated.
40. A method according to claim 39, in which the column defines an interior, and the jacking and supporting is carried out in the interior.
41. A method according to any of claims 32 to 40, in which the column includes one member which is positioned above another member.
42. A method according to claim 41, in which the positioning of the one member includes lifting the one member by buoyancy means.
43. A method according to claim 42, in which the one member is lifted above water level by the buoyancy means.
44. A method according to claims 42 or 43, in which the lifting step includes sequentially lifting, holding and packing the one member, and then lifting again.
45. A method of assembly of a wind turbine assembly, the wind turbine assembly including a wind turbine mounting on which a wind turbine is mountable, the mounting including a column, the method including a step of erecting the column, the method including any of the steps defined in claims 32 to 44.
46. A method according to claim 45, in which the wind turbine assembly includes a wind turbine, which includes a housing, and the method includes mounting the housing to the column.
47. A method according to claim 46, when dependent on claim 38 or any claim dependent thereon, in which the housing is mounted to the column while the column is in the retracted position.
48. A method according to claims 46 or 47, in which the housing is lifted by buoyancy means.
49. A method according to claim 48, in which the housing is lifted above water level by the buoyancy means.
50. A method according to any of claims 45 to 49, in which the wind turbine assembly includes a wind turbine, and the wind turbine includes drive means.
51. A method according to claim 50, in which the method includes mounting the drive means.
52. A method according to claim 51, in which the method includes mounting the drive means when the column is in the extended position.
53. A method according to any of claims 45 to 52, in which the wind turbine assembly is as defined in any of claims 17 to 31.
54. A mounting substantially as hereinbefore described and with reference to the accompanying drawings.
55. A wind turbine assembly substantially as hereinbefore described and with reference to the accompanying drawings.
56. A method of assembly of a mounting for a wind turbine substantially as hereinbefore described and with reference to the accompanying drawings.
57. A method of assembly of a wind turbine assembly substantially as hereinbefore described and with reference to the accompanying drawings
58. An electricity generating system including a wind turbine assembly according to any of claims 17 to 31.]
59. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.