'Game changer' claimed as floating wind turbine achieves first major component swap at sea

Scotland's Kincardine wind farm has claimed an industry first by carrying out an exchange of a major floating offshore wind turbine (FOWT) component on location and without requiring a tow-to-port operation.

The pioneering O&M operation was achieved through a collaboration of companies including Vestas, LiftOff, Kincardine Offshore Windfarm Ltd (KOWL) and consortium parners Dragados SA and Cobra Wind International Limited (CWIL), according to a statement released by KOWL.

Performing a major component exchange (MCE) while a floating wind turbine remained on site will provide encouragement to proponents of the technology.

Even the most ardent backers of floating wind have been forced to admit that the sector faces concerns regarding cost and overall economic viability, especially if major component exchanges are necessarily to require disconnecting FOWTs, towing them to port, then back again for re-connecting, following maintenance and repair.

The Kincardine project was executed from an offshore support vessel (OSV), supported by crew transfer vessels (CTVs) and did not require a powerful AHTS.

To perform the process, a patented up-tower crane supplied by LiftOff of the Netherlands was temporarily installed atop the Vestas turbine.

Vestas prepared the wind turbine generator and decommissioned the old generator, allowing LiftOff to lift it from the nacelle and lowered it to the deck of the floater, where it was then transferred to the OSV.

Using the same methodology, the replacement generator was then transferred to the floater and lifted into the nacelle using the up-tower crane, called GenHook.

This operation involved the application of load-control mechanisms during lifting activities carried out in a marine motion environment affected by wind, waves, and currents.

"The wind energy industry has been seeking technological alternatives to improve processes when generator repairs or replacements are required. The recently completed in-situ generator exchange on a Vestas V164-9.5MW turbine, using LiftOff up-tower crane technology and specialised teams from LiftOff and Vestas, has proven that major component exchanges can be done offshore, without the need for massive offshore cranes, or the need to tow the wind turbine to port," the joint statement read.

The operations were planned using multiple weather forecasts as well as real-time motion monitoring and the OSV phase of the operation carried out in less than a month, including mobilisation and demobilisation of all equipment.

"Applying this groundbreaking new process has eliminated the need for tow-to-port operations, which has previously been the only way to perform MCEs at floating offshore wind farms. Tow-to-port operations generate a large carbon footprint, involve high costs, and create extended periods of turbine downtime," the partners stated.

The 50 MW Kincardine Offshore windfarm, owned by Spain's Dragados, is located 15km off the coast of Aberdeenshire, Scotland. With its five 9.5MW Vestas turbines, it was the world's biggest floating array when it was commissioned 2021, providing clean electricity to Scotland’s grid.

José Polimón Olabarrieta, Dragados project manager and general manager at KOWL, said: “By pushing the boundaries of innovation and embracing the requirement to improve previous processes, we have achieved a world-first technical solution that redefines the future for the renewables industry. In Dragados we are delighted to have produced a solution that can be implemented on-site, which will negate the requirement to disconnect and tow the turbine ashore for repair.

“This solution for repairs has the potential to have positive sector-wide impact. With the floating offshore windfarm industry still in a fledgling state, it is crucial owners and operators across the world learn from projects such as this and share best practices.

Game changer?

LiftOff managing director Eelko May said: “After several years of developing technical solutions for fixed-bottom and floating wind turbines, we are proud to demonstrate at Kincardine that our innovative up-tower crane technology is ideal for use on offshore wind turbines. This is a total game-changer, which will transform the industry for the better, and will continue to lower the cost of renewable energy.”

Thore Abel, director, global service contracting, at Vestas said: “Tow-to-port operations for major component exchanges have been a key challenge in the floating wind space for years. This innovative in-situ solution, using an up-tower crane on a geared Vestas turbine, showcases that alternative means to towing activities are no longer just possible on paper or in animations, but a proven solution. This can pave the way to viable improvements in feasibility of floating wind projects around the world and should encourage the industry to continue its innovative approach.”

While up-tower crane technology was described as "commonplace for onshore wind turbines in some markets", the statement released by the companies involved in the Kincardine operation made it clear that they see the project as a game-changer.

"Proving this technology on offshore wind turbines, and especially on floating wind turbines, marks the start of an era where the tow-to-port operations are no longer needed for several types of floating turbine repairs" their statement read.

"This advancement in major component exchanges significantly improves the commercial viability of floating wind as a source of renewable energy, while it simultaneously reduces the carbon emissions in comparison to a conventional tow-to-port operation".