A system for raising, positioning and lowering an offshore wind turbine blade and tower maintenance device

Abstract

The invention relates to systems for raising, positioning and lowering offshore wind turbine maintenance tools and maintenance robots. The claimed system comprising a carrying rope; a carrying rope winch; three balancing ropes; three balancing means; three balancing ropes' winches; three balancing ropes' pulleys or blocks, fixed to the balancing means. The carrying rope is adapted to be operably connected to the carrying rope winch and the central rod of the maintenance device. The balancing ropes are adapted to be operably put through the balancing ropes' pulleys or blocks; wherein the ends one of the balancing ropes are adapted to be operably connected to the balancing ropes' winches and the balancing rods. The pulleys or blocks are configured to be responsive to the directional pull of the balancing rope, such that it moves in alignment with the direction from which the balancing rope exerts its pull. The balancing means with balancing ropes' pulleys or blocks are adapted to be submersible. According to an embodiment, the claimed system may further comprise a carrying rope pulley or a block, adapted to be suspended from the wind turbine nacelle, or a wind turbine hub. In this embodiment the carrying rope needs to be operably put through the carrying rope pulley or a block.

Description

[0001] A system for raising, positioning and lowering an offshore wind turbine blade and tower maintenance device

[0002] Technical Field

[0003]

[0001] The invention relates to devices and systems, used for servicing, including cleaning, inspection, deicing and painting of offshore wind turbine blades and tower, in particular, to systems for raising, positioning and lowering offshore wind turbine maintenance tools and maintenance robots.

[0004] Background Art

[0005]

[0002] Wind turbine blades demand regular maintenance during their operational life. They can sustain damage from events such as lightning hits, bird collisions, and wear on the leading edge and surface. Blades that are damaged, malfunctioning, unclean, or encased in ice can diminish the wind turbine's overall efficiency or even cause blade breakage or complete turbine failure.

[0006]

[0003] Offshore wind turbine maintenance and servicing face distinct challenges compared to the onshore turbines. The aquatic environment is typically much harsher, with stronger winds and waves. Waves cause additional challenges for wind turbine maintenance operation. Waves can cause service vessels to pitch and roll, which can make it difficult to approach and stay alongside a turbine for servicing. In addition to changing strength and direction of a wind, wave motion complicate positioning of the wind turbine maintenance equipment. Also, the waves can cause increased wear and tear on maintenance equipment. Working on an offshore turbine can be riskier due to the combination of height, high winds, and the open sea. Emergency response times might be slower compared to onshore locations.

[0007]

[0004] Traditionally, blade inspection and maintenance are made by industrial climbers, who use rope and cradle access to get to the blade. More comfortable workspace can ensure use of a platform travelling along the wind turbine. However, safer, less expensive and less time-consuming solutions for wind turbine blade maintenance use robots or arrangements, which do not require presence of workers at heights.

[0005] There is known using an UAV for an offshore wind turbine maintenance (W02020001714A1), where an UAV is deployed from a maintenance vehicle, stationed proximal to the wind turbine.

[0008]

[0006] There is known a maintenance device for maintaining an offshore wind turbine (EP3409942B1), comprising a maintenance platform having a notch designed to receive a pylon of the wind turbine; and travel means for causing the maintenance platform to travel along the pylon of the wind turbine in vertical longitudinal axial direction.

[0009]

[0007] There is known a method for performing maintenance on an outer surface of an offshore wind turbine part (W02019086087A1), comprising the steps of: transporting an access system, comprising two or more detachably assembled modules, to a site of the offshore wind turbine; transferring the two or more modules of the access system to a transition platform at a lower part of the offshore wind turbine; stopping operation of the offshore wind turbine; assembling the access system from the two or more modules at the transition platform; performing maintenance on an outer surface of a wind turbine part, using the access system, and restarting operation of the offshore wind turbine,

[0010]

[0008] There is known a maintenance system for a tower located in the sea (EP2969883B1) comprising a maintenance caplsule, designed to transport cargo and maintenance personnel to the wind turbine tower; a swivelable crane assembly attached to the tower that includes a boom extending over the sea and a trolley that moves along this boom.

[0011]

[0009] There is known a method for performing maintenance on object (US2020171552A1) comprising positioning a wind turbine blade so its leading edge is vertical, stretching at least one rope over the blade, and attaching a maintenance device to the blade. This includes connecting the device to the rope, fixing two other ropes to control its inclination, and securing the device to the blade with frame assemblies. The device moves along the leading edge, driven by gravity, performing maintenance as it goes. The two ropes adjust the device's angle relative to the ground, and each frame assembly has pivotably connected first and second frames..

[0010] There is known a system for service tools positioning relative to the offshore wind turbine blade and tower (W02021198734A1), comprising: a truss system, a rigging and a rigging pulling in and letting out means. The truss system, comprising booms, pivotally attached to a supporting means, which are adapted to be leaned against or releasably fixed to a wind turbine tower or wind turbine tower mooring elements; wherein the rigging and a rigging pulling in and letting out means are operably connected with the truss system, so to allow lowering and raising service tools used for offshore wind turbine blade and tower maintenance.

[0012] [Oil] There is known a device for wind turbine blade and tower maintenance and a system for raising and lowering of the device (EP3880958). The device comprising a central rod, three balancing rods, a central hub, at least one tool arm adapted to releasably fix one or more tools aimed for surface maintenance; and a tool arm motor adapted to adjust the angle of the tool arm in respect of the central rod. The central rod and three balancing rods are connected to the central hub. The three balancing rods, as well as central rod or the central hub are adapted to be connected to carrying and balancing ropes or cables. The system for positioning said device comprising a main rope having ends one and two; a main rope winch or an anchor; a pulley or a block; the carrying rope having end one and two; a carrying rope winch; three balancing ropes, each having ends one and two and balancing means; wherein end one of the main rope is adapted to be operably connected to the winch or anchor; end two of the main rope is adapted to be connected to the pulley or block, which is can be hung over the wind turbine blade; the carrying rope is adapted to be operably put through the pulley or block; end one of the carrying rope is adapted to be operably connected to the carrying rope winch; the end two of the carrying rope is adapted to be connected to the central rod of the arrangement; wherein ends one of the balancing ropes are adapted to be connected to the balancing rods; ends two of the balancing ropes are adapted to be connected to the balancing means, which can be in the form of anchored or movable winches. Although the solution described in EP3880958 proved to be very effective and successful for onshore wind turbine maintenance, offshore wind turbine maintenance presents unique challenges due to the dynamic marine environment, wave action, and accessibility issues that are not encountered on land.

[0013] Summary of the Invention

[0014]

[0012] The invention provides for a system for raising, positioning and lowering offshore wind turbine blade and tower maintenance devices, such as maintenance robots and maintenance tools described in EP3880958, or other maintenance devices. The invention addresses issues related to the safe and efficient maintenance of offshore wind turbines.

[0015]

[0013] The arrangement described in EP3880958 comprises i.a. a central rod, three balancing rods, a central hub, at least one tool arm adapted to releasably fix one or more tools aimed for surface maintenance; and a tool arm motor adapted to adjust the angle of the tool arm in respect of the central rod. The central rod and three balancing rods are connected to the central hub. The three balancing rods, as well as central rod or the central hub are adapted to be connected to carrying and balancing ropes or cables.

[0016]

[0014] The claimed system comprising a carrying rope; a carrying rope winch; three balancing ropes; three balancing means; three balancing ropes’ winches; three balancing ropes’ pulleys or blocks, fixed to the balancing means. The carrying rope is adapted to be operably connected to the carrying rope winch and the central rod of the maintenance device. The balancing ropes are adapted to be operably put through the balancing ropes’ pulleys or blocks; wherein the ends one of the balancing ropes are adapted to be operably connected to the balancing ropes’ winches and the balancing rods. The pulleys or blocks are configured to be responsive to the directional pull of the balancing rope, such that it moves in alignment with the direction from which the balancing rope exerts its pull. The balancing means with balancing ropes’ pulleys or blocks are adapted to be submersible. They can be in the form of anchors or sinkers, or in the form of submersible unmanned watercrafts. According to an embodiment, the claimed system may further comprise a carrying rope pulley or a block, adapted to be suspended from the wind turbine nacelle, or a wind turbine hub. In this embodiment the carrying rope needs to be operably put through the carrying rope pulley or a block. The system further comprises an anemometer communicatively coupled to a controller, configured to receive data related to the speed and direction of the wind. The controller is configured to calculate optimal position of the balancing means from the wind turbine tower to balance the load caused by wind upon receiving information from the anemometer on the wind direction and / or strength and to adjust the position of the balancing means automatically or notify the operator for manual repositioning.

[0017]

[0015] The claimed method of raising, positioning and lowering an offshore wind turbine blade and tower maintenance device comprises the steps of: (i) placing the balancing ropes’ winches on a transition piece of an offshore wind turbine; (ii) positioning the carrying rope winch at a selected location associated with the wind turbine; (hi) connecting the end one of the carrying rope to the carrying rope winch; and connecting the end two of the carrying rope to the central rod of the maintenance device; (iv) placing the balancing means on the seabed around the wind turbine tower; (v) connecting the ends two of the balancing ropes to the balancing rods of the maintenance device; putting the balancing ropes through the balancing ropes’ pulleys or blocks; connecting the ends one of the balancing ropes to the balancing ropes’ winches; (vi) operating the carrying rope winch to raise, position and lower an offshore wind turbine blade and tower maintenance device and operating one or more balancing ropes’ winches to position an offshore wind turbine blade and tower maintenance device. The step (ii) of positioning the carrying rope winch at a selected location associated with the wind turbine may comprise (a) placing the carrying rope winch on a wind turbine nacelle or inside a nacelle, or in a hub of an offshore wind turbine; or (b) suspending the carrying rope pulley or a block from the wind turbine nacelle or a wind turbine hub; and placing the carrying rope winch on a transition piece of an offshore wind turbine (in this case the step (hi) of connecting the end one of the carrying rope to the carrying rope winch and connecting the end two of the carrying rope to the central rod comprises also putting the carrying rope through the carrying rope pulley or a block suspended from the wind turbine nacelle or a wind turbine hub.

[0018]

[0016] According to yet another embodiment, at the step [iv] of placing the balancing means on the seabed around the wind turbine tower, the balancing means are placed so that a distance from the balancing means to the wind turbine tower would be substantially half of the wind turbine height counting from the seabed line to the top of the wind turbine nacelle.

[0019]

[0017] Fig. 1 shows a perspective view of an embodiment of the prior art arrangement designed to be used for wind turbine maintenance;

[0020] Fig. 2 - a schematic view of the claimed arrangement in operation, featuring three balancing ropes’ winches, positioned on a transition piece of an offshore wind turbine; three balancing means positioned on a seabed around the wind turbine tower; a carrying rope winch positioned on a transition piece of an offshore wind turbine; and a maintenance tool positioned in front of a wind turbine blade;

[0021] Fig. 3 - a schematic enlarged view of a transition piece of an offshore wind turbine according to one embodiment, featuring three balancing ropes’ winches;

[0022] Fig. 4 - a schematic enlarged view of a transition piece of an offshore wind turbine and a seabed around the wind turbine tower, featuring balancing ropes’ winches, a carrying rope winch, balancing means positioned on a seabed around the wind turbine tower, the balancing means provided with pulleys or blocks;

[0023] Fig. 5 - shows a perspective view of an embodiment of a balancing means provided with pulley or block, which is designed to be responsive to the directional pull of the balancing rope;

[0024] Fig. 6A-6C - schematically show embodiments of a setup of the carrying rope put through a suspended carrying rope pulley or a block, wherein Fig. 6A shows carrying rope pulley or a block suspended from the wind turbine hub; Fig. 6B - carrying rope pulley or a block suspended from one side of the wind turbine nacelle; Fig. 6C - carrying rope pulley or a block suspended from another side of the wind turbine nacelle;

[0025] Fig. 7 - shows a schematical top view of the wind turbine with the claimed arrangement in operation, showing principle of determination of the distance increase for the two balancing means in a proportional relationship, taking into account the ratio of their respective angles to the wind direction;

[0026] Fig. 8 - shows principle of positioning of the balancing means on the seabed around the wind turbine tower at a distance substantially half of the wind turbine height counting from the seabed line to the top of the wind turbine nacelle.

[0027] Detailed Description of Invention

[0028]

[0018] The claimed system is suitable for raising, positioning and lowering an offshore wind turbine blade and tower maintenance device, comprising: a central rod (1) and three balancing rods (2) connected to a central hub (7), wherein the three balancing rods (2), as well as the central rod (1) or the central hub (7) are adapted to be connected to carrying and balancing ropes or cables (Fig. 1). The claimed system comprising a carrying rope (20) having end one and two; a carrying rope winch (25); three balancing ropes (21), each having ends one and two; three balancing means (26); three balancing ropes’ winches (27); three balancing ropes’ pulleys or blocks (28), fixed to the balancing means (26) (Fig. 2-3).

[0029]

[0019] The end one of the carrying rope (20) is adapted to be operably connected to the carrying rope winch (25); the end two of the carrying rope (20) is adapted to be operably connected to the central rod (1) of the maintenance device. The balancing ropes (21) are adapted to be operably put through the balancing ropes’ pulleys or blocks (28); the ends one of the balancing ropes (21) are adapted to be operably connected to the balancing ropes’ winches (27); the ends two of the balancing ropes (21) are adapted to be operably connected to the balancing rods (2) of the maintenance device. The balancing means (26) with balancing ropes’ pulleys or blocks (28) are adapted to be submersible (Fig. 4).

[0020] The claimed system further comprising an anemometer communicatively coupled to a controller, configured to receive data related to the speed and direction of the wind; wherein the controller is configured to calculate optimal position of the balancing means (26) from the wind turbine tower to balance the load caused by wind upon receiving information from the anemometer on the wind direction and / or strength.

[0030]

[0021] According to one embodiment, the balancing means (26) are in the form of anchors or sinkers comprising pulleys or blocks (28).

[0031]

[0022] According to another embodiment, the anchors or sinkers comprising pulleys or blocks (28) comprise multiple detachable weights. Each individual weights designed to be within 5-40 kg. The pulley or block (28) is configured to be responsive to the directional pull of the balancing rope (21), such that it moves in alignment with the direction from which the balancing rope (21) exerts its pull (i.e. the pulley or block (28) is designed to be able to move based on the direction of the force from the balancing rope (21)) - Fig. 5. The pulley or block (28) is mounted on bearings or another low-friction system that allows itto move freely around an axis. For instance, if the balancing rope (21) pulls to the left, the pulley / block (28) will move to the left; if the balancing rope (21) pulls upwards, the pulley / block (28) moves upwards, and so on. This feature allows the balancing means to adapt to different forces and conditions, contributing to the stability of the system it is a part of.

[0032]

[0023] According to yet another embodiment, the balancing means (26) comprise three submersible unmanned watercrafts with pulleys or blocks (28) installed thereon. Under this embodiment the controller is further configured to (a) actuate a movement mechanism to adjust the position of at least one balancing means (26) to a new location on the wind side, thereby maintaining a desired distance from the wind turbine tower to balance the load caused by wind; or (b) activate an alert to inform an operator of the offshore wind turbine blade and tower maintenance device of the need for manual adjustment of location of the balancing means (26) on the seabed, optionally, also providing the result of the calculation to the operator to position or re-position of the balancing means (26) on the seabed.

[0024] According to one of the preferable embodiments, the claimed system further comprises a carrying rope pulley or a block (24), adapted to be suspended from the wind turbine nacelle, or a wind turbine hub, wherein the carrying rope (20) is adapted to be operably put through the carrying rope pulley or a block (24) - Fig. 6A- 6C.

[0033]

[0025] The claimed method of raising, positioning and lowering an offshore wind turbine blade and tower maintenance device comprises the steps of: (i) placing the balancing ropes’ winches (27) on a transition piece of an offshore wind turbine; (ii) positioning the carrying rope winch (25) at a selected location associated with the wind turbine; (hi) connecting the end one of the carrying rope (20) to the carrying rope winch (25); and connecting the end two of the carrying rope (20) to the central rod (1) of the maintenance device; (iv) placing the balancing means (26) on the seabed around the wind turbine tower; (v) connecting the ends two of the balancing ropes (21) to the balancing rods (2) of the maintenance device; putting the balancing ropes (21) through the balancing ropes’ pulleys or blocks (28); connecting the ends one of the balancing ropes (21) to the balancing ropes’ winches (27); (vi) operating the carrying rope winch (25) to raise, position and lower an offshore wind turbine blade and tower maintenance device and operating one or more balancing ropes’ winches (27) to position an offshore wind turbine blade and tower maintenance device. The method further comprises the step of detecting the direction and strength of a wind by means of anemometer communicatively coupled to a controller, configured to receive data related to the speed and direction of the wind; wherein, upon detection of a wind direction and / or strength, the controller calculates optimal position of the balancing means (26) from the wind turbine tower to balance the load caused by wind and provides the result of the calculation to an operator of the offshore wind turbine blade and tower maintenance device to position or re-position of the balancing means (26) on the seabed. The results can be provided to an operator visually via display unit, audibly by alert or voice prompt, by means of haptic feedback, or electronic message by means of SMS, email or a push-up notification to an operator’s device, e.g. a smartphone, a laptop, PC, or a tablet. Alternatively, upon detection of a change in a wind direction and / or strength, the controller (a) actuates a movement mechanism to adjust the position of at least one balancing means (26) to a new location on the wind side, thereby maintaining a desired distance from the wind turbine tower to balance the load caused by wind; or (b) activates an alert to inform an operator of the offshore wind turbine blade and tower maintenance device of the need for manual adjustment of location of the balancing means (26) on the seabed.

[0026] According to another embodiment the step (ii) of positioning the carrying rope winch (25) at a selected location associated with the wind turbine comprises placing the carrying rope winch (25) on a wind turbine nacelle or inside a nacelle, or in a hub of an offshore wind turbine.

[0034]

[0027] An alternative solution could be the step of suspending the carrying rope pulley or a block (24) from the wind turbine nacelle or a wind turbine hub; and wherein the step (ii) of positioning the carrying rope winch (25) ata selected location associated with the wind turbine comprises placing the carrying rope winch (25) on a transition piece of an offshore wind turbine; and the step (hi) of connecting the end one of the carrying rope (20) to the carrying rope winch (25) and connecting the end two of the carrying rope (20) to the central rod (1) of the maintenance device comprises also putting the carrying rope (20) through the carrying rope pulley or a block (24) suspended from the wind turbine nacelle or a wind turbine hub.

[0035]

[0028] According to yet another embodiment, at the step (iv) of placing the balancing means (26) on the seabed around the wind turbine tower, the balancing means (26) are placed so that a distance from the balancing means (26) to the wind turbine tower would be substantially half of the wind turbine height counting from the seabed line to the top of the wind turbine nacelle.

[0036]

[0029] According to yet another embodiment, the controller may be configured to: (a) generate and transmit instructions or signals based on detected wind speed such that for every increase of 5 m / s in wind speed, a movement mechanism is actuated to increase the distance of the balancing means (26) from the wind turbine tower by 10- 30%, more preferably by 15-25%, and oriented to face the wind direction; (b) in instances where the wind direction affects two balancing means (26), further comprising instructions to generate and transmit further instructions or signals to actuate the movement mechanism of the balancing means (26), ensuring that the increase in distance is distributed proportionally based on the angle difference between the two balancing means (26) and the incoming wind direction, such that the amount of distance increase dl and d3 for the two balancing means (26) is allocated in a proportional relationship, governed by the ratio of their respective angles Alpha and Beta to the wind direction, such that the ratio of these distances, dl to d3, is determined by the equation Alpha / Beta = dl / d3 (Fig. 7). Under this embodiment the system is designed to react to increases in wind speed by positioning the balancing means (26) at a greater distance from the wind turbine tower, which provides counterbalance or stabilization for the system for raising, positioning and lowering an offshore wind turbine blade and tower maintenance device.

[0037]

[0030] The claimed system operates as follows. The balancing ropes’ winches (27) are positioned on a transition piece of an offshore wind turbine. The carrying rope winch (25) is positioned at a selected location associated with the wind turbine, which can be either (a) on a wind turbine nacelle or inside a nacelle, or in a hub of an offshore wind turbine, or (b) on a transition piece of an offshore wind turbine. The end one of the carrying rope (20) is connected to the carrying rope winch (25), the end two of the carrying rope (20) is connected to the central rod (1) of the maintenance device. In the event the carrying rope winch (25) is positioned on a transition piece of an offshore wind turbine, the carrying rope pulley or a block (24) is suspended from the wind turbine nacelle or a wind turbine hub and the step of connecting the end one of the carrying rope (20) to the carrying rope winch (25) and connecting the end two of the carrying rope (20) to the central rod (1) comprises also putting the carrying rope (20) through the carrying rope pulley or a block (24) suspended from the wind turbine nacelle or a wind turbine hub. Further the balancing means (26) are positioned on the seabed around the wind turbine tower. The ends two of the balancing ropes (21) are connected to the balancing rods (2) of the maintenance device. The balancing ropes (21) are put through the balancing ropes’ pulleys or blocks (28). The ends one of the balancing ropes (21) are connected to the balancing ropes’ winches (27). The carrying rope winch (25) is operated to raise, position and lower an offshore wind turbine blade and tower maintenance device, while one or more balancing ropes’ winches (27) are operated to position an offshore wind turbine blade and tower maintenance device. When positioning the balancing means (26) on the seabed around the wind turbine tower, the balancing means (26) are preferably positioned so that a distance from the balancing means (26) to the wind turbine tower would be substantially half of the wind turbine height counting from the seabed line to the top of the wind turbine nacelle (Fig. 8). The operation of the system further comprises detecting the direction and strength of a wind by means of anemometer communicatively coupled to a controller, configured to receive data related to the speed and direction of the wind. Upon detection of a wind direction and / or strength, the controller calculates optimal position of the balancing means (26) from the wind turbine tower to balance the load caused by wind and provides the result of the calculation to an operator of the offshore wind turbine blade and tower maintenance device to position or re-position of the balancing means (26) on the seabed. The results can be provided to an operator, or the system may adjust position of the balancing means (26) on the seabed automatically, by actuation of a movement mechanism to adjust the position of at least one balancing means (26) to a new location on the wind side, thereby maintaining a desired distance from the wind turbine tower to balance the load caused by wind.

Claims

Claims1. A system for raising, positioning and lowering an offshore wind turbine blade and tower maintenance device, said maintenance device comprising: a central rod (1) and three balancing rods (2) connected to a central hub (7), wherein the three balancing rods (2), as well as the central rod (1) or the central hub (7) are adapted to be connected to carrying and balancing ropes or cables; the system comprising a carrying rope (20) having end one and two; a carrying rope winch (25); three balancing ropes (21), each having ends one and two; three balancing means (26); three balancing ropes’ winches (27); three balancing ropes’ pulleys or blocks (28), fixed to the balancing means (26); wherein the end one of the carrying rope (20) is adapted to be operably connected to the carrying rope winch (25); the end two of the carrying rope (20) is adapted to be operably connected to the central rod (1) of the maintenance device; wherein the balancing ropes (21) are adapted to be operably put through the balancing ropes’ pulleys or blocks (28); the ends one of the balancing ropes (21) are adapted to be operably connected to the balancing ropes’ winches (27); the ends two of the balancing ropes (21) are adapted to be operably connected to the balancing rods (2) of the maintenance device; wherein the balancing means (26) with balancing ropes’ pulleys or blocks (28) are adapted to be submersible; wherein the system further comprising an anemometer communicatively coupled to a controller, configured to receive data related to the speed and direction of the wind; wherein the controller is configured to calculate optimal position of the balancing means (26) from the wind turbine tower to balance the load caused by wind upon receiving information from the anemometer on the wind direction and / or strength.

2. The system according to claim 1, wherein the balancing means (26) are in the form of anchors or sinkers comprising pulleys or blocks (28).

3. The system according to claim 1, wherein the balancing means (26) comprise three submersible unmanned watercrafts with pulleys or blocks (28) installed thereon; wherein the controller is further configured to (a) actuate a movement mechanism to adjust the position of at least one balancing means (26) to a new location on the wind side, thereby maintaining a desired distance from the wind turbine tower to balance the load caused by wind; or (b) activate an alert to inform an operator of the offshore wind turbine blade and tower maintenance device of the need for manual adjustment of location of the balancing means (26) on the seabed, optionally, also providing the result of the calculation to the operator to position or re-position of the balancing means (26) on the seabed.

4. The system according to claim 2, wherein the anchors or sinkers comprising pulleys or blocks (28) comprise multiple detachable weights, each individual weights designed to be within 5-40 kg; wherein the pulleys or blocks (28) are configured to be responsive to the directional pull of the balancing rope (21), such that it rotationally moves in alignment with the direction from which the balancing rope (21) exerts its pull.

5. The system according to any preceding claims, wherein it further comprises a carrying rope pulley or a block (24), adapted to be suspended from the wind turbine nacelle, or a wind turbine hub, wherein the carrying rope (20) is adapted to be operably put through the carrying rope pulley or a block (24).

6. A method of for raising, positioning and lowering an offshore wind turbine blade and tower maintenance device of claims 1-5, comprising the steps of:- placing the balancing ropes’ winches (27) on a transition piece of an offshore wind turbine;- positioning the carrying rope winch (25) at a selected location associated with the wind turbine;- connecting the end one of the carrying rope (20) to the carrying rope winch (25); and connecting the end two of the carrying rope (20) to the central rod (1) of the maintenance device;- placing the balancing means (26) on the seabed around the wind turbine tower;- connecting the ends two of the balancing ropes (21) to the balancing rods (2) of the maintenance device; putting the balancing ropes (21) through the balancing ropes’ pulleys or blocks (28); connecting the ends one of the balancing ropes (21) to the balancing ropes’ winches (27);- operating the carrying rope winch (25) to raise, position and lower an offshore wind turbine blade and tower maintenance device and operating one or more balancing ropes’ winches (27) to position an offshore wind turbine blade and tower maintenance device;- detecting the direction and strength of a wind by means of anemometer communicatively coupled to a controller, configured to receive data related to the speed and direction of the wind; wherein, upon detection of a wind direction and / or strength, the controller calculates optimal position of the balancing means (26) from the wind turbine tower to balance the load caused by wind and(a) actuates a movement mechanism to adjust the position of at least one balancing means (26) to a new location on the wind side, thereby maintaining a desired distance from the wind turbine tower to balance the load caused by wind; or(b) activates an alert to inform an operator of the offshore wind turbine blade and tower maintenance device of the need for manual adjustment of location of the balancing means (26) on the seabed, optionally, also providing the result of the calculation to the operator to position or re-position of the balancing means (26) on the seabed.

7. The method according to claim 6, wherein the step of positioning the carrying rope winch (25) at a selected location associated with the wind turbine comprises placing the carrying rope winch (25) on a nacelle or inside a nacelle, or in a hub of an offshore wind turbine.

8. The method according to claim 6, wherein the method comprises the step of suspending the carrying rope pulley or a block (24) from the wind turbine nacelle or a wind turbine hub; and wherein the step of positioning the carrying rope winch (25) at a selected location associated with the wind turbine comprises placing the carrying rope winch (25) on a transition piece of an offshore wind turbine; and the step of connecting the end one of the carrying rope (20) to the carrying rope winch (25) and connecting the end two of the carrying rope (20) to the central rod (1) of the maintenance device comprises also putting the carrying rope (20) through the carrying rope pulley or a block (24) suspended from the wind turbine nacelle or a wind turbine hub.

9. The method according to any claims from 6 to 8, wherein at the step of placing the balancing means (26) on the seabed around the wind turbine tower, the balancing means (26) are placed so that a distance from the balancing means (26) to the wind turbine tower would be substantially half of the wind turbine height counting from the seabed line to the top of the wind turbine nacelle.

10. The method according to any claims from 6 to 9, wherein the controller is configured to: (a) generate and transmit instructions or signals based on detected wind speed such that for every increase of 5 m / s in wind speed, a movement mechanism is actuated to increase the distance of the balancing means (26) from the wind turbine tower by 10-30%, more preferably by 15-25%, and oriented to face the wind direction;(b) in instances where the wind direction affects two balancing means (26), further comprising instructions to generate and transmit further instructions or signals to actuate the movement mechanism of the balancing means (26), ensuring that the increase in distance is distributed proportionally based on the angle difference between the two balancing means (26) and the incoming wind direction, such that the amount of distance increase dl and d3 for the two balancing means (26) isallocated in a proportional relationship, governed by the ratio of their respective angles Alpha and Beta to the wind direction, such that the ratio of these distances, dl to d3, is determined by the equation Alpha / Beta = dl / d3.

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