A Turkish yard that has built up a track record of building service operation vessels for the offshore wind energy industry has launched the latest innovative example of the type.
Wind of Change is being built at Cemre in Turkey for Louis Dreyfus Armateurs (LDA) and, when completed, will enter into a long-term contract with offshore wind energy leader Ørsted.
Delivery of Wind of Change is expected early next year. It will be operated on the Borkum Riffgrund 1 and 2 and Gode Wind 1 and 2 offshore windfarms in Germany providing a maintenance base for technicians to service wind turbines. The vessel has accommodation for 90, including more than 60 windfarm technicians.
The 83.0-m vessel has a beam of 19.4 m and will be equipped with a dynamic motion-compensated gangway with what naval architect Salt Ship Design described as “a unique onboard logistic solution”. LDA worked closely with Salt Ship Design to develop a vessel tailored for the needs of the offshore wind industry. “This has resulted in a very purpose-driven SOV,” said the Norwegian naval architect.
Technicians will be transferred to the wind turbines via a specially designed daughter craft (in case of good weather conditions) and will use the motion compensated gangway in heavy seas. The daughter craft will be capable of transferring eight windfarm technicians and 1 tonne of cargo to a turbine. The motion compensated gangway will have a range of approximately 19 m and will be complemented by a unique motion compensated crane with a lifting capacity of 1 tonne at 23 m.
The windfarm service vessel will have a DC power distribution grid in the form of ABB’s OnBoard DC grid, allowing batteries to be integrated into it, making the ship more environmentally friendly and efficient. ABB is installing the DC grid along with what it calls a power and energy management system enabling the generators to run at variable speeds while also charging the batteries.
In a statement about the system, ABB marine and ports global product manager for Onboard DC Grid John Olav Lindtjørn said “Energy storage can be used for many purposes on board. Sometimes it serves as the sole energy source, but for this windfarm vessel, it is being deployed as an effective supporting element for the main engine.”
The DC grid will integrate two sets of batteries that will be used primarily for spinning reserve and peak shaving so that power peaks during operation can be covered by the battery rather than starting another engine. Battery power can also act as backup for running generators, reducing the need to run spare generator capacity. The level of operating efficiency available in a hybrid power system reduces wear and tear on engines and significantly increases fuel efficiency at lower loads where, in traditional AC power systems, generators run at a fixed maximum speed regardless of the power demand on board. Apart from enhancing the ship’s green credentials in the environmentally conscious offshore wind industry, ABB also points to a benefit for the vessel’s crew: reduced vibration when the hybrid system is on battery power.
MAN is supplying the 8L21/31 variable-speed gensets for the vessel, which will also feature the company's EPROX energy saving electric propulsion system, which will further reduce the vessel’s fuel consumption and emissions. The engines will be prepared for IMO Tier III and set up so that they can be retrofitted at a later date with an SCR system. This is to cater for the possibility that IMO Tier III NOx emission limits could be introduced, without obligation, in NOx emission-control areas in the North Sea and Baltic.
Uptime in Norway was contracted to supply the walk-to-work gangway for the newbuild. TTS Group and Ulstein provided the motion compensated crane. Together, the companies were awarded a contract for a TTS Colibri motion compensated crane for the SOV. The new crane combines TTS’s expertise in crane design and manufacturing with Ulstein’s expertise in motion technology and analysis.
“Two features make the TTS Colibri unique compared to other solutions in the market,” claimed Ulstein Equipment managing director Gilbert Rezette. “Firstly, the Colibri system is a stand-alone add-on device for a standard offshore crane. It adds functionality, while the crane maintains its functionality as a full-fledged offshore crane including deepwater subsea capabilities. However, what makes this system truly unique is its groundbreaking anti-sway technology, which also allows it to mitigate wind-induced motions that act directly on the load.
“3D motion compensation technology is not new to the industry and has enabled greater operability for personnel transfer between vessels and fixed offshore platforms through the use of motion compensated gangways,” he said. “However, operations typically require personnel and equipment to be transferred between a vessel and platform. Hence, TTS Colibri is a natural step in enhanced vessel operability, providing motion compensated lifting to match the increased operability offered by motion compensated gangways.”
In April 2018, Ørsted placed a contract with the Turkish yards for a second SOV, to be delivered in 2021, for the Hornsea Project 2 offshore windfarm.
A sister vessel to Wind of Change, which was ordered in 2017, the second ship was also be designed in close co-operation with Salt Ship Design. Like the first vessel it will have the innovative hybrid propulsion system using diesel generators and ABB’s OnBoard DC grid and incorporate an energy storage system using batteries.