Lessons learned in the offshore oil and gas sector can also be applied in offshore wind
With its long coastline, offshore expertise and willingness to embrace new, greener solutions and technology, it is not surprising that Norway is grasping the opportunities offered by wind power with gusto.
In June 2018, the Norwegian energy minister, Terje Søviknes met with companies to discuss constructing demonstration floating windfarms to showcase Norwegian expertise in this area, following a resolution being approved by Norway’s Parliament, calling for such projects. And this national enthusiasm is nothing new – in 2013 the government committed to spending Nkr20Bn (US$2.5Bn) to boost the country’s wind capacity to more than 2 GW by 2020.
But industry, as well as the government, backs wind too. The Norwegian Shipowners backed the floating windfarm projects, saying “wind energy has significant potential for decarbonising energy production, improving energy security and providing European companies with competitive advantages,” and noted that wind provided 300,000 jobs and Nkr699Bn in annual turnover in Europe alone.
It was Norwegian oil major Equinor that built – and holds a 75% stake in – the Hywind Scotland floating windfarm offshore Peterhead in the UK. Equinor changed its name from Statoil this year, reflecting the company’s broader focus on energy generally rather than simply oil and gas. The company’s board chairman Jon Erik Reinhardsen said at the time “The world is changing, and so is Statoil. The biggest transition our modern-day energy system has ever seen is underway and we aim to be at the forefront of this development.”
Norwegian shipbuilding expertise has also been put to good use in the wind sector, with many yards turning to it to fill their orderbooks when demand for vessels for the offshore oil and gas sector plummeted during the downturn. The vessels that construct and service offshore windfarms have many of the same characteristics required of vessels that service the platforms of the offshore oil and gas sector, requiring good stationkeeping, seaworthiness and the ability to perform in rough conditions.
Netherlands-based Acta Marine chose Ulstein Verft to construct Acta Auriga, its walk-to-work vessel and announced an order for a second vessel of the same type at the Offshore Wind Journal conference in February, while the first was still under construction.
Acta Auriga and its sister ship are dynamic positioning class 2 SX195 design walk-to-work construction support vessels. The SX195 design is 93.4 m long with a breadth of 18 m and is optimised for offshore wind. It has a centrally positioned motion-compensated gangway and elevator tower for personnel and cargo transfers, supplied by SMST in the Netherlands.
Perhaps the most striking feature of Ulstein’s SX195 design is its hull shape, which incorporates Ulstein’s X-STERN and the company’s well-known, distinctive X-BOW.
The logistics on board are optimised to enhance workflow and are complimented by significant storage capacity and a ‘stepless’ approach to the offshore installations for windfarm personnel.
With most of the main equipment and operations in the aft ship, the vessels operate stern-first while in the field, keeping the X-STERN towards the weather preventing slamming, minimising noise and vibration and allowing crew and windfarm technicians to rest between shifts. Accomodation is provided for up to 120 people.
Acta Auriga completed sea trials in March and started its two-year contract with Ocean Breeze Energy (OBE) at the BARD Offshore 1 windfarm offshore Germany in May 2018. OBE’s managing director for technology, Jean Huby said “The vessel is expected to increase the productivity of offshore personnel by around 25%, because it will enable our teams to operate in a much more flexible manner with even shorter waiting times than before.”
Denmark’s Esvagt opted for Norwegian knowhow when it chose Havyard as a partner to design its technological service operation vessel (SOV) Esvagt Mercator.
The ship was designed for the highest possible level of efficiency and low fuel consumption, providing a base for 36 windfarm technicians for up to two weeks at sea.
Built at Cemre shipyard in Turkey, the Havyard 831 SOV is 58.50 m overall with a beam of 16.60 m and draught of 5.50 m. It has a service speed of approximately 12 knots. Havyard and Cemre have co-operated on more than 30 newbuild vessels since 2005.
Unlike most SOVs, which use motion-compensated gangways to transfer personnel to turbines, Esvagt Mercator uses three safe transfer boats. Esvagt opted to take this route because of experience gained building and operating fast rescue boats.
Esvagt’s chief operating officer, Kristian Ole Jakobsen said “We have co-operated well with Havyard on developing this vessel, and we know that the quality of their deliveries is excellent.”
Havyard’s vice president of sales, Gisle Vinjevoll Thrane, said “It's a wonderful vessel that has all the qualities required to service offshore windfarms in an efficient and secure manner, with the least possible impact on the environment. The vessel confirms once again that our designs create added value and increased competitiveness for our customers.”
The vessel is the first of two Havyard 831 SOVs vessels for the Danish shipowner. The second vessel, for which a contract was signed earlier this year, is scheduled for completion by August 2019.
Norwegian yards are also receiving orders for cable-lay vessels that connect windfarms to the grid.
French subsea specialist Nexans Subsea Operations placed an order with Ulstein Verft for a large, DP3 cable-lay vessel in July 2018.
The ST-297 design vessel, designed by fellow Norwegian company Skipsteknisk, will be outfitted for power cable-laying, including bundle laying, cable jointing and repair and cable system protection and trenching. Ulstein Verft will construct the vessel and prepare it for the topside equipment.
The design has been developed for operation in rough weather and has high levels of manoeuvrability and stationkeeping.
The vessel will have a turntable with a cable capacity of 10,000 tonnes. A fibre optic basket will be capable of holding 450 tonnes. The vessel will be 149.9 m long with a deadweight of 17,000 tonnes and accommodate 90 people.
And in April, Italy’s Prysmian Group chose Vard to build a cable-laying vessel in a contract valued at €170M (US$200M).
The new vessel will be capable of installing cables in water depths exceeding 2,000 m and will undertake a range of operations using burial systems including heavy-duty ploughs. It will be designed to have a reduced environmental footprint, a length of 172 m and a beam of 34 m with accommodation for 120 people.
The vessel is being designed by Vard Design in Ålesund, Norway. Construction is expected to get under way by end-2018 and the vessel will be delivered by Vard Brattvaag in Q4 2020. The hull will be built at Vard Tulcea in Romania.
Several of the Vard group’s specialised subsidiaries are also involved in the project through deliveries of equipment and solutions.
Prysmian Group’s senior vice president for energy projects Massimo Battaini described the vessel as “a strategic asset” that would bolster the company’s ability to undertake turnkey projects and deliver end-to-end engineering, procurement, construction and installation projects. It will also strengthen the group’s interconnection and offshore wind project execution capabilities.