13 minute read
Offshore Wind
The lifting vessel Innovation was deployed on the Borssele I&II wind farms. (Photograph: DEME)
by Paul Schaap, PAS Publicaties
As is the case with the oil and gas industry, Dutch offshore contractors and their suppliers have succeeded in acquiring a leading global position in the engineering, procurement, installation and commissioning of offshore wind farms. Dutch contractors not only deliver excellent performance on their home market, but thanks to their new and innovative techniques and remarkable vessels, they also set the pace elsewhere in the world, too.
On the Dutch market, work is currently underway on the fast-paced installation of a series of large offshore wind farms, off the coast of the Netherlands. This work is the result of the Offshore Wind Energy Roadmap 2030 laid out by the Dutch government, that provides for the completion of 11 GW of offshore wind farm capacity in Dutch coastal waters, by 2030. Within this same framework, the Borssele I&II wind farms (generating 752 MW) were completed in 2020, and III&IV (with a capacity of 731.5 MW), achieved an advanced stage of completion. Borssele I&II were laid out for Ørsted, 22 kilometres off the coast of Zeeland with the installation of 94 Siemens Gamesa 8 MW wind turbine by DEME Offshore. DEME deployed its own installation vessels Innovation, Sea Installer and Sea Challenger for this work. Elsewhere, with its vessel the Nexus, Van Oord laid a total of 190 kilometres of inter-array cables, that were subsequently buried in the seabed by the trencher DigIt. For its part, Boskalis Subsea Cables & Flexibles took responsibility for laying the energy export cables to shore. The Borssele III&IV project has been developed by the Blauwwind consortium. 77 MHI Vestas wind turbines, each generating 9.5 MW have already been installed in this wind farm. For this project, Van Oord has been appointed what is known as the balance of plant contractor, deploying the Aeolus for the installation work, and the
Nexus for the laying of the inter-array cables. For this farm, too, Boskalis Subsea Cables & Flexibles laid the energy export cables. Finally, VLCV, a joint venture between Van Leeuwen and C-Ventus, deployed its direct drill system for the landfall for all the energy export cables.
On behalf of the Two Towers Consortium, Van Oord also undertook the layout of the experimental Borssele V wind farm. The remarkable feature of this farm, consisting of just two wind turbines each generating 9.5 MW, is the use of an innovative slip joint instead of grouted or bolted connections, to place the transition piece on the monopile foundation. Other innovations tested in the Borssele V farm include thermally sprayed aluminium, impressed current cathodic protection optimisation, oval cable entry holes, and eco-friendly scour protection. The offshore substation platforms for the two Borssele wind farms were designed by Iv-Offshore & Energy, fabricated by HSM Offshore, and installed offshore by one of the crane vessels operated by Seaway 7. The accommodation platform Seafox 7 was then deployed during the commissioning of the substations. The majority of the monopile foundations were fabricated by Sif, an organisation that operates a special dedicated facility for this work, on the Second Maasvlakte. Finally, Acta Marine deployed a fleet of workboats to support the wind farm installation projects.
Hollandse Kust Zuid
Another offshore wind farm currently taking shape off the Dutch coast is the Hollandse Kust Zuid (HKZ) project. Just like its counterpart in Borssele, this project also involves four large plots (numbered I to IV). Project developer at HKZ is Vattenfall. The farm will be laid out between 18 and 36 kilometres off the coast of Zuid-Holland, and in total will comprise 140 Siemens Gamesa wind turbines, each generating 11 MW. HKZ I/II and HKZ III/IV
Van Oord deployed its vessel Svanen for the Kriegers Flak wind farm. (Photograph: Van Oord)
will both deliver a capacity of 770 MW. In the runup to this project, Fugro has already completed a marine unexploded ordnance risk mitigation project in the affected sea area. N-Sea played an important role in the inspection and identification of unexploded ordnance, that was subsequently rendered harmless by the Royal Netherlands Navy. During the fourth quarter of 2020, Sif made a start on the fabrication of the 140 transition piece-less monopile foundations, with lengths ranging between 68 and 85 metres. Vattenfall has awarded the order for the transport and installation of the 140 monopile foundations and the laying of the 315 kilometres of inter-array cables supplied by TKF, to Seaway 7. This installation and cable-laying work is due to be carried out in 2021 and 2022. In the meantime, on behalf of TenneT, Van Oord deployed its vessel the Nexus to lay the energy export cables from the HKZ Alpha offshore substation to the Second Maasvlakte. The trencher Dig-It was then deployed to bury these cables in the seabed. Later this year, Van Oord plans to also lay the energy export cables from the HKZ Beta substation to the Second Maasvlakte. For its part, Heerema Marine Contractors deployed the world’s largest semi-submersible crane vessel Sleipnir for the offshore installation of the 3,200-tonne, six-legged jacket for the HKZ Alpha substation. The impressive crane vessel is scheduled to also install the topside for this platform at the end of 2021. All in all, a great deal of work has already been completed, and is indeed set to continue off the coast of the Netherlands, in the wind energy sector. According to the Dutch Offshore Wind Energy Roadmap 2030, however, there is still plenty more to come. The roadmap in fact outlines the construction of a whole series of other offshore wind farms, including the 759 MW Hollandse Kust Noord (HKN) farm, the 1,400 MW Hollandse Kust West (HKW) farm, the 4,000 MW IJmuiden Ver (IJV) farm and a large 700 MW farm to The North of the Wadden Islands (TNW). Van Oord has already completed there the installation of the 600 MW Gemini wind farm.
Contractors
At the end of August 2020, Van Oord completed the transport and installation of 72 monopiles and 72 transition pieces for the Danish Kriegers Flak park, in the Baltic Sea. The company deployed ten workboats, including the crane vessel Svanen, with its lifting capacity of 8,000 tonnes. Elsewhere, Van Oord installed all 89 foundations for the Fryslân wind farm, a nearshore park in the IJsselmeer lake in the Netherlands, at the end of December 2020. Van Oord has already signed new contracts for the Hollandse Kust Noord wind farm and for the supply and installation of the monopile foundations and inter-array cables for the Sofia wind farm on the Dogger Bank, in British waters. The Dutch contractor will be deploying its installation vessels Aeolus, MPI Adventure and MPI Resolution and the cablelayer Nexus for the HKN project, while the Aeolus and Nexus will also be working on the Sofia farm project. Finally, Van Oord has ordered the construction of a nextgeneration green cable-laying vessel for the offshore wind energy sector. The vessel is due to be handed over in 2023. The company has also already signed contracts for the development of wind farms in Estonia and Japan.
HSM Offshore fabricated the substations for the Borssele windfarms. (Photograph: PAS Publicaties)
In 2020, Boskalis deployed its vessel the Ndurance to install the cables for the Triton Knoll wind farm in the Baltic Sea, and was also responsible for the burying of the cables in the seabed. Elsewhere, the Ndeavor was deployed to lay cables at the Moray East offshore wind farm, and at the Hornsea Two wind farm off the coast of the English county of Yorkshire, the Boka Falcon was deployed for the laying and trenching of the energy export cables. As part of a consortium with Bouygues and Saipem, Boskalis was also involved in the design, construction and installation of 71 concrete gravity base structures for the Fécamp offshore wind farm, currently being built off the coast of Normandy. Another major project for Boskalis involves the transport, assembly and installation of five large floating wind turbines as part of the Kincardine offshore wind farm currently under construction close to Invergordon. Alongside the heavy transport vessel Fjord, the AHTS vessels Manta, Nicobar and Princess and the tugboat Seraya have been employed on this work. Boskalis has also purchased a purpose-built pre-lay plough for use in the wind energy sector. The first task for this new plough will be the trenching and burial
of 380 kilometres of export cables for the Hornsea Two offshore wind farm. The new plough has already been installed on board the Boka Falcon. A new addition to the fleet for the wind energy sector is the support vessel Boka Tiamat. Finally, a former drilling ship is being converted into a crane vessel for Boskalis, in Dubai. This vessel will be equipped with a 4,000-tonne Huisman crane and will be rechristened Bokalift 2. Following handover, the vessel is due to be deployed in Taiwan, for the installation of 62 jackets for the Changfang and Xidao wind farms. DEME Offshore has been contracted to deploy the Living Stone to lay 650 kilometres of inter-array cables for the Dogger Bank A and Dogger Bank B wind farms. Together with a Taiwanese partner, DEME has also ordered the construction of the Green Jade. This wind turbine installation vessel will be equipped with a 4,000-tonne Huisman crane.
Another company that is becoming increasingly involved in installation work for the wind energy sector is Heerema Marine Contractors. Not only are they active in the Dutch sector of the North Sea, but also beyond. In October 2020, the Sleipnir placed the jackets for the RCS and OSS platform in the Hornsea Two offshore wind farm. Off the coast of Taiwan, the Aegir has made a start on the transport and installation of 111 foundations and two substations for the Greater Changhua 1 and Greater Changhua 2a offshore wind farms. In 2020, Seaway 7, the Renewables & Heavy Lifting business of Subsea 7, was also highly active in the offshore wind sector, in particular with its crane vessels. The Seaway Strashnov, for example, placed the monopile foundations and the two substations for the Triton Knoll wind farm. Seaway 7 also decided to have the Seven Phoenix converted into a special inter-array grid and export cable installation and trenching support vessel. Once the conversion work is completed, she will be rechristened the Seaway Phoenix. Elsewhere, the crane vessel Seaway Yudin was equipped with a pile installation frame for installation work off the coast of Taiwan.
Engineering
In the field of engineering work, Dutch engineering companies have also acquired a leading position in the wind energy sector. GustoMSC, for example, has completed a whole raft of designs for wind turbine installation vessels. Many have already in fact been built or are planned. OHT subsidiary VIND Offshore Installation recently decided to order the construction of two wind turbine installation vessels, each equipped with a 2,500tonne crane. Swire Blue Ocean also plans to have a similar vessel built, but with a 1,600-tonne crane. GustoMSC has also produced a design for the wind turbine installation vessel currently being built in Brownsville, in the American state of Texas, by Dominion Energy. This vessel is due to be equipped with a 2,200-tonne crane. For its part, Scorpio Bulkers has signed a letter of intent with GustoMSC for the design of a similar vessel to be equipped with a 1,500-tonne leg encircling crane, that will be supplied by Huisman. Finally, on behalf of the Japanese market, GustoMSC is hard at work designing special lifting vessels. Iv-Offshore & Energy has signed an agreement with TenneT TSO for the front-end engineering and design of the first 525 kV offshore grid connections to the IJmuiden Ver wind farm. Together with HSM Offshore, Iv-Offshore & Energy will be responsible for the design and fabrication of the topside for the Neart na Gaoithe offshore wind farm that is due to be installed in Scottish waters. A contract has also been taken out for the engineering of the Sofia highvoltage direct current platform.
ENGIE Fabricom and Iemants have been awarded the order for the design, fabrication, transport and installation of a 700 MW substation for the Hollandse Kust Noord offshore wind farm. The same contract also includes two orders for the construction of substations for Hollands Kust West. KCI, the Engineers, will be acting as engineering consultant for the wind turbine foundations for the Jeju Hanlim offshore wind farm in South Korea. KENC Engineering has been awarded an order by Van Oord for the design of a lifting tool for the pin piles for the French Saint-Brieuc farm. The tool in question will then be fabricated by Breman Machinery. KENC Engineering has
Transporting one of the foundations for the Kincardine wind farm. (Photograph: PAS Publicaties)
The cable layer Nexus will be working on the Sofia wind farm project. (Photograph: Van Oord)
also recently presented two new automatic boat landing systems for safe transfers between a CTV and a large vessel. Finally, Fugro has been involved in geotechnical survey assignments and all the related activities for the offshore wind energy sector in the Netherlands but also abroad, including the United States, Taiwan, Denmark, Japan and the United Kingdom.
Suppliers
Sif and Smulders are active players on the export market. Together, they have manufactured the monopiles and transition pieces for the Akita-Noshiro wind farm in Taiwan, and recently won the joint order for the fabrication of all the monopiles and transition pieces for the Dogger Bank A and Dogger Bank B wind farms. Elsewhere, Sif supplied the foundations for the Saint-Nazaire wind farm due to be built in French waters, and the monopiles and transition pieces for the Triton Knoll wind farm currently under construction in British waters. Just before the end of the year, the company was also awarded the order to supply monopiles for the Hollandse Kust Noord wind farm, by Van Oord. SPT Offshore has been contracted by Guangzhou Salvage for the installation of three suction pile jacket foundations as part of the CTGNE Yangxi Shaba Phase 1 offshore windfarm. Another contract from China awarded to SPT Offshore involves the design and installation of 15 suction pile jackets for Area A and 62 suction pile jackets for Area C of the Fujian Changle Wahai offshore windfarm. Huisman, designers and builders of cranes, have continued to attract attention with a series of contracts for cranes for wind turbine installation vessels. The same applies to the Walk-toWork (W2W) designers and builders Ampelmann, SMST, and the consortium Bosch-Rexroth/Bargemaster. Damen Shipyards has been hard at work building a series of fast crew suppliers, Royal IHC has presented a new design for a service operation vessel and KenzFigee has signed a contract for the supply of two 3-tonne electric hydraulic ram luffing offshore cranes for the Neart na Gaoithe substation. For its part, IHC IQIP has been working on the construction of special jacket pile grippers for a wind project in Taiwan. Dutch operators active in the wind energy sector include Acta Marine, Vroon Offshore Services, GloMar Offshore, Seafox Operations and Jumbo Shipping, and heavy transport specialist Mammoet.
This overview is unable to include every Dutch company active in the design, installation, operation or maintenance of wind farms but it does reflect the essential role played by Dutch companies, in this global market.
