In order to allow for a safe and cost-efficient lifting of components (1) from a service vessel (2) to a location on an off-shore wind turbine generator (3) or lowering of components from a location on an off-shore wind turbine generator to a service vessel a method involving the use of a handshake-tool (10) is provided my means of which the component to be lifted or lowered can easily be transferred from one crane to another.

A main shaft fixture for fixing a main shaft on a wind turbine during installation and repair work on heavy parts of the wind turbine nacelle, in the case where the fixture is formed of several sections for mounting on stable structural parts in the nacelle, including the nacelle's bottom frame. The main shaft fixture has adjustable pressure mandrels with tap shoes, which cause the fixture to be usable regardless of the turbine main shaft geometry, such that it can be mounted without fixing the rotor. The main shaft fixture also has facilities for mounting of a lightweight crane and a self-hoisting crane with a ground-based winch, respectively, as well as a rotor lock which, in combination with actuators of the main shaft fixture, enables the main shaft and the main shaft bearing to be sufficiently displaced vertically from its bearing in the nacelle to service or replace the bearing.

A method including operating the wind turbine in a first operating mode which an auxiliary system of the wind turbine is supplied with electrical power from an energy storage system of the wind turbine, wherein in the first operating mode, a first group auxiliary power consumers of the auxiliary system and a second group auxiliary power consumers of the auxiliary system are supplied with electrical power from the energy storage system. Upon fulfillment of a predefined condition, the wind turbine is operated in a second operating mode wherein the power supply from the energy storage system to the first group of auxiliary power consumers is ceased. Upon a charging state of the energy storage system reaching or dropping below a predetermined charging level, the wind turbine may be operated in a third operating mode in which auxiliary power supply is ceased.

Methods are for extending a crane tower along a wind turbine, assembling a crane tower, shortening a crane tower, and constructing a wind turbine tower, in addition to various related apparatus. In certain examples, a crane tower is supported upon the wind turbine tower and extended along the wind turbine tower, where the crane tower includes a crane at or near an upper end thereof, and the wind turbine tower is provided with apparatus including a lifter to elevate the crane tower to create space for inserting one or more extension sections at or near a crane tower base and adding them to the crane tower for extending the crane tower longitudinally along the wind turbine tower.

Wind turbine blade installation apparatus for attaching a wind turbine blade (13) to the hub (12) of a wind turbine (11). The apparatus comprises a primary frame (14) for supporting the wind turbine blade (13) in a vertical orientation. An interface (23) connects the wind turbine blade (13) to the primary frame (14). A rigid connector (15) connects the primary frame (14) to the boom (6) of a crane (4). The rigid connector (15) includes a moveable coupling to the boom (6) such that the primary frame (14) is moveable between a first position for receiving the blade (13) lifted by the crane (4), and a second position for holding a root (131) of the blade (13) in its vertical orientation above the head (9) of the boom (6) of the crane (4).

A method (100) of servicing or installing a component of a wind turbine (10) using a crane (50), the wind turbine (10) comprising a nacelle (16) and a rotor hub (20) coupled to the nacelle (16) and rotatable about a rotor axis, the method (100) comprising rotating the rotor hub (20) about the rotor axis to a first rotational position; lifting the crane (50) to the rotor hub (20) while the rotor hub (20) is positioned at the first rotational position; mounting the crane (50) to a mounting portion (21) of the rotor hub (20) while the rotor hub (20) is positioned at the first rotational position; and rotating the rotor hub (20) together with the crane (50) from the first rotational position to a second rotational position.

A method for the arrangement of at least one component during the installation of a wind turbine is provided, wherein the component is releasably attached to a tower segment prior to a coupling of the tower segment to a tower segment support structure, wherein the tower segment forms at least a section of a tower of the wind turbine to be installed and wherein the component is attached to an attachment area at the outer surface of the tower segment, wherein the component is moved from the attachment area to an arrangement position after coupling of the tower segment to the tower segment support structure.

Wind turbine installation method the installation method including: providing a nacelle (2) at a wind turbine erection site, said nacelle (2) comprising: a main unit (20), arranged to be connected to the wind turbine tower (3), and configured for housing a rotor-supporting assembly of the wind-turbine: at least one auxiliary unit (21, 22) housing an operative component (34) forming part of the power conversion assembly, wherein: the main unit (20) and the auxiliary unit (21, 22) are separate units configured to be connected by a unit fixation structure at an interface, and wherein the operative component (34) is supportable directly on the main unit (20), said method further including: receiving a said main unit (20) and an auxiliary unit (21, 22) and an operative component (34) to said site of erection of the wind turbine, attaching to said main unit (20) the said auxiliary unit (21, 22) and said operative component (34). and attaching a lifting yoke (50) to the main unit (20) and hoisting the main unit (20) together with the auxiliary unit (21, 22) by means of a crane attached to the lifting yoke (50), wherein the auxiliary unit (21, 22) is supported and lifted by the main unit (20) during the hoisting, and installing the main unit (20) and the attached auxiliary unit (21, 22) at the tower top.

An offshore electricity production assembly comprising a floating platform, a wind turbine fixed to the floating platform, and inclined mooring tendons, the floating platform comprising: a tubular central buoyant column extending along a longitudinal axis intended to be vertical, the column having an immersed portion defining a first average external diameter, and a plurality of tubular radial buoyant pontoons protruding from the column along radial axes spaced around the longitudinal axis, each of the pontoons defining a second average external diameter, the pontoons being immersed in a body of water.

The first average external diameter is larger than the second average external diameter.

A method for installing at least one damper unit in a tower section of a wind turbine tower is disclosed. The tower section is arranged with its centre axis in a substantially horizontal orientation, and a guiderail is introduced into the tower section. A trolley is mounted on a part of the guiderail extending out of the tower section, the damper unit is mounted on the trolley, and the trolley with the damper unit is moved along the guiderail to a position inside the tower section. The damper unit is positioned in an installation position being vertically offset from the centre axis of the tower section, wherein the positioning comprises elevating the damper unit, and the damper unit is attached to the tower section at the installation position.