A method for assembling a wind turbine, including: attaching an elevator carriage (27) to a nacelle (9) to form a carriage-nacelle assembly (27,9); and mounting the carriage-nacelle assembly (27,9) on to a tower (3) as a unit.

A method for assembling a wind turbine, including: attaching an elevator carriage (27) to a nacelle (9) to form a carriage-nacelle assembly (27,9); and mounting the carriage-nacelle assembly (27,9) on to a tower (3) as a unit.

Described is a tool and apparatus for positioning a blade for a wind turbine the wind turbine including a tower and a rotatable hub on the tower. The tool is mounted on a side of the tower so that the blade is supported on the tower in an initial configuration. The tool includes a first part arranged to be angularly movable relative to a second part for tilting the blade with respect to the tower to position the blade in a position that can allow the blade to be connected to the hub.

Described is a tool and apparatus for positioning a blade for a wind turbine the wind turbine including a tower and a rotatable hub on the tower. The tool is mounted on a side of the tower so that the blade is supported on the tower in an initial configuration. The tool includes a first part arranged to be angularly movable relative to a second part for tilting the blade with respect to the tower to position the blade in a position that can allow the blade to be connected to the hub.

Provided is a tool arrangement for pivoting a tower or a tower segment from a non-erected position to an erected position, including a bottom tool device with a first device section with an attachment to removably attach the first device section to a bottom mounting section, and with a second device section adapted to be arranged on the ground and being attachable or attached to the first device section, wherein the bottom tool device includes a pivot axis at least when the first and the second device sections are attached to each other, wherein the tower or the tower segment, when fixed to the bottom tool device, is pivotable around the pivot axis when being erected, wherein, when the tower or the tower segment is fixed to the bottom tool device, the pivot axis is perpendicular to the longitudinal axis of the tower or the tower segment.

A method for planning repowering of a wind energy plant is disclosed. The wind energy plant is positioned at a site and comprises a plurality of original wind turbines arranged at distributed positions within the site. Historical data related to the original wind turbines is retrieved. The historical data is collected over a previous time period and during operation of the original wind turbines. Meteorological conditions at the site of the wind energy plant are estimated based on the retrieved historical data. The repowering of the wind energy plant is planned based on the estimated meteorological data, including planning replacement of the original wind turbines by replacement wind turbines to be positioned at the positions of the original wind turbines.

A method for planning repowering of a wind energy plant is disclosed. The wind energy plant is positioned at a site and comprises a plurality of original wind turbines arranged at distributed positions within the site. Historical data related to the original wind turbines is retrieved. The historical data is collected over a previous time period and during operation of the original wind turbines. Meteorological conditions at the site of the wind energy plant are estimated based on the retrieved historical data. The repowering of the wind energy plant is planned based on the estimated meteorological data, including planning replacement of the original wind turbines by replacement wind turbines to be positioned at the positions of the original wind turbines.

The present invention relates to a blade positioning system configured for positioning wind turbine blades at a hub of a nacelle of a wind turbine from an installation vessel at an offshore location, the blade positioning system comprising: the installation vessel comprising: — at least one lifting device configured for lifting wind turbine components, and — an auxiliary support tower extending upwardly from the installation vessel, the auxiliary support tower comprising: o a nacelle support for supporting the nacelle, o a root end moving assembly defining a guide path which extends over a vertical distance, the root end moving assembly comprising a movable root end support base and a root end support configured for supporting and guiding the root end of the blade, the root end support being connected to the movable root end support base, the root end support being movable along the guide path, the root end moving assembly being configured for moving the root end of the blade along the guide path from the engagement position to an installation position, the at least one lifting device being configured for lifting the nacelle onto the auxiliary support tower, wherein the at least one lifting device and the root end moving assembly are configured to jointly support and jointly move the blade upwards towards the hub, wherein during the movement the root end is supported by the root end support and the lifting device carries a majority of the vertical loads on the blade.

The present invention relates to a blade positioning system configured for positioning wind turbine blades at a hub of a nacelle of a wind turbine from an installation vessel at an offshore location, the blade positioning system comprising: the installation vessel comprising: — at least one lifting device configured for lifting wind turbine components, and — an auxiliary support tower extending upwardly from the installation vessel, the auxiliary support tower comprising: o a nacelle support for supporting the nacelle, o a root end moving assembly defining a guide path which extends over a vertical distance, the root end moving assembly comprising a movable root end support base and a root end support configured for supporting and guiding the root end of the blade, the root end support being connected to the movable root end support base, the root end support being movable along the guide path, the root end moving assembly being configured for moving the root end of the blade along the guide path from the engagement position to an installation position, the at least one lifting device being configured for lifting the nacelle onto the auxiliary support tower, wherein the at least one lifting device and the root end moving assembly are configured to jointly support and jointly move the blade upwards towards the hub, wherein during the movement the root end is supported by the root end support and the lifting device carries a majority of the vertical loads on the blade.

The invention relates to a device (100), a system (10) and a method for modifying the cross section of a tower section (1) of a wind turbine, wherein the tower section comprises a flange (4) located at an end (3) of the tower section having a plurality of through holes (5) spaced around its circumference for securing said tower section to another wind turbine section. The method comprises securing tensioning mechanism (14) to each of a pair of said plurality of through holes in the flange of the tower section, said pair of holes being generally opposed; and applying a tensile force between said pair of holes in the flange of the tower section.