This article was first published in our January/February 2011 issue. Renewable Energy Focus is proud to be the official "Innovation in wind technology" media partner for this year's All-Energy event in Aberdeen, taking place on 23-24 May. The All-Energy Exhibition & Conference is the UK's largest renewables event devoted to all forms of clean and renewable energy. It is being held at an important time as the UK continues to assume a dominant role in the offshore wind sector and many companies look to the immense supply chain opportunities this brings.
Suppliers to the UK's offshore oil and gas sector have spent decades developing and testing solutions to deep water challenges. But despite the best efforts of some, the UK oil and gas supply chain has had minimal involvement in nearshore wind farms installations to date. Subsea work such as surveying, grouting and cabling have been the chief activities.
Aberdeen-based Integrated Subsea Services has provided cabling and Remotely Operated Vehicle (ROV) services for nearshore projects, as well as other tasks such as installing cable protection for inter-array cables.
“All our skills are fairly easily transferable to the renewable energy sector,” says David Gault, the company's renewables department manager. “The work is no easier, just different. Up to now it's been close to shore but we're getting into an area where you do need far more offshore experience to be successful. The differences are getting fewer.”
The vast majority of nearshore turbine deployments have so far been carried out by the turbine manufacturers themselves, dedicated renewables contractors or civil engineers.
But in the more challenging offshore environment further away from the coast, could oil and gas suppliers have even more involvement?
With much of the UK's oil and gas expertise in the area, the appetite for collaboration is particularly sharp in the north-east of Scotland. “By and large, the oil and gas supply chain is ready made for maritime renewables,” says Jeremy Cresswell, chair of the Aberdeen Renewable Energy Group (AREG). “But it has been a fractured dialogue.”
|“…the oil and gas supply chain is ready made for maritime renewables, but it has been a fractured dialogue…”
|- Jeremy Cresswell, AREG
According to Vestas however, which maintains around 40 per cent of the world's operational offshore wind turbines, the oil and gas supply chain still cannot meet wind's installation needs.
“So far, we have not been able to benefit from any synergies as the offshore wind industry has very different requirements,” says Asger Pedersen, technical director, performance and customer relations at Vestas. “The vessels used within the oil and gas industry are in general not the optimum choice for work within the offshore wind industry as they are designed for other purposes.”
Pederson points to the need for specialised vessels capable of carrying a large load of delicate turbines, complete with cranes able to make the many high lifts required for installation.
The sheer number of turbines demands that the installation equipment and processes will have to be “productised” in order to keep capital and operating expenditure down. Hence the preference for specially designed vessels, foundations and harbours.
There have already been several examples of this approach: In July 2010 for example, A2SEA – owned by DONG Energy and counting Siemens as a shareholder – signed a US$139 million contract with Chinese COSCO Shipyard Group Co Ltd for the construction of a new vessel specially designed for the purpose of installing offshore wind turbines. It will be delivered in 2012. It will be a jack-up vessel optimised to operate at water depths of up to 45 metres.
And RWE Innogy also commissioned two installation vessels in 2010. According to RWE, the vessels are able to transport and install up to four of the largest available offshore wind turbines including foundations. Featuring satellite control, these ships will be fixed with centimetre-precision for construction work at sea, and operate in water depths of more than 40 metres. The first two vessels are intended to be completed in 2011. The order value per vessel is around Euro 100 million, says RWE.
But before such bespoke vessels become available, the offshore wind industry must make do with what is currently available. And pay a premium.
“The prices for these vessels are very influenced by the current market situation and the day rates can vary several hundred per cent for the same vessel,” says Pederson. “The rates are also normally higher than what is affordable in the offshore wind industry.”
There is currently strong demand for cable laying vessels in the North Sea for non-renewable projects. But oil and gas rates remain a bugbear. “There is a general feeling in offshore wind that oil and gas costs need to come down by about 20 to 25 per cent,” notes David Rennie, oil and gas director at Scottish Enterprise. “But it's not necessarily about overall cost, rather the cost per unit of electricity generated. Experienced contractors can help bring unit costs down in different ways, like preventing days lost.”
Rennie gives an example of a nearshore wind-related operation which the contractor estimated would take 11 days. It eventually took 44: “An experienced oil and gas contractor we spoke to said that they would have done it in 20 days,” he says.”
Offshore wind meets oil and gas
Besides subsea operations and safety, design and fabrication are where the biggest synergies lie. The GBF consortium's gravity base foundation is a good example.
“The GBF concept has been designed for repeatability, with a large number of ‘small’ foundations as opposed to one or two huge installations and production platforms, and hence lower costs,” says Michael Starling, business development, renewable energy at BMT Group.
|According to Vestas however, the oil and gas supply chain still cannot meet wind’s installation needs.
According to Starling, many parts of GBF's enabling design technology and processes (tug tows, ballasting structures, and concrete) have previously been used in oil installations. This holds true for numerous elements of the planned Round 3 offshore wind farms that will be further out to sea, from control system design and build from companies like Capelrig, to specialist anti-fouling and anti-corrosion coatings from International Paint.
BiFab's jackets for the Ormonde field are shining examples of oil-derived expertise literally supporting offshore wind. Harland and Wolff is another experienced oil and gas contractor with a number of renewable projects under its belt.
The Belfast-based company has completed a Transformer Platform and Jacket for the Bard 1 farm and was responsible for the storage, assembly and offloading of 60 Vestas turbines for the Robin Rigg farm. Showing the breadth of its capabilities, it also stepped in to repair three jackups that experienced failures during the project. The company is also familiar with wave and tidal: having built most of the SeaGen tidal generator and the Wavebob prototype. It is currently constructing Scotrenewables' 250kw tidal turbine (SRTT).
In addition, the company is to provide logistic and assembly services for the Ormonde project and recently won a contract to supply two offshore substations for the Gwynt y Môr development. With topsides weighing thousands of tons, sitting on a steel jacket, these far-offshore substations are very similar to oil and gas installations.
Case study: Oil and gas supplier goes tidal
Innovations to harness tidal forces always throw up operational difficulties, particularly to do with positioning of the devices on the ocean floor – as well as their connections to shore.
Triscom Marine – a specialist in subsea positioning techniques pioneered in offshore oil & gas construction, has recently been involved in the installation and testing of a tidal energy test rig in Orkney:
“We were required to inspect some subsea cabling in the area of a massive OpenHydro tidal turbine off the island of Eday,” explains Tristan Thorne, senior surveyor, “because it was important to know what was happening in the deep inlet where surges of water are funnelled along a particular channel. As the turbine is mounted on the seabed, deep enough not to interfere with shipping traffic, its positioning is critical, as are the cables in the vicinity that lead to shore.
“We carry out a lot of work like this, mapping inshore cable routes which are often in shallow and dynamic environments,” adds Thorne, “and very often we find damage or anomalies that must be accurately marked for reporting to clients”.
The company has added its latest USBL positioning system – the Applied Acoustics' Easytrak Nexus – to its equipment pool, to meet the increasing requirement for accurate underwater positioning tasks. The equipment is the latest generation of USBL tracking systems from Applied Acoustics that has Spread Spectrum Technology incorporated into it to improve the accuracy of positioning information. This technology also rejects unwanted reflected signals that have made operations in challenging locations such as ports and harbours difficult in the past. It is a rack-mounted system with built in PC that displays positioning information on a separate monitor, where the activity of up to 10 subsea targets within a specified operating area can be viewed.
“The rules are long, established and proven in offshore oil and gas,” says David McVeigh, sales and marketing manager at Harland and Wolff, “…[and] we bring [those] to bear on renewables projects.”
McVeigh cites his company's experience in designing and building light, stressed-skin structures, most recently in the conversion of the Blackford Dolphin semi-submersible, and its willingness to work closely with clients to adapt designs to new areas, notably HVAC design with Siemens in the substations for Gwynt y Môr.
This enthusiasm extends to investment in new plants specifically for renewable projects, such as steel rolling machinery. “Round 3 structures will be larger, and that lends itself even more to our facilities” he adds. The company is in a good position to capitalise on offshore wind.
H&S knowledge transfer
Safety procedures, often learned the hard way, must top the list of other transferable oil and gas skills. For decades, anyone visiting a UK offshore installation has had to attend Petrofac's BOSIET survival course. This ensures all personnel are trained to the same minimum standard. This is not the approach with offshore wind.
There have also been calls for offshore wind farm operators to adopt the safety case model mandatory in offshore oil and gas, as well as other industries such as nuclear. Currently there are no sector-specific obligations, with conventional health and safety regulations followed instead.
Perhaps the best example of collaboration to date is the European Offshore Wind Deployment Centre, which recently won an EC grant of up to Euro 40 million. Offshore wind farm developers and their suppliers will test new turbine and foundation designs at the centre, prove existing products and receive independent validation and accreditation before deployment.
There is also growing political pressure. Organised by Scottish Enterprise and chaired by Scotland's First Minister Alex Salmond, last December's Offshore Energy Summit brought together representatives from both sides of the fence, including Scottish Power, Subsea 7 and Dong Energy. “We want to get the message out to the oil and gas companies about the scale of the opportunity here,” says Scottish Enterprise's David Rennie.
Collaboration will require effort. Oil and gas suppliers have to demonstrate the necessary flexibility and appetite for new business – even if it doesn't quite provide the margins many are used to. And renewable operators may find that it's a lot cheaper in the long run not to re-invent the wheel.
James Lawson writes about renewable energy, and has been a business journalist, editor and publisher for 17 years. He previously worked as an engineer in the UK oil and gas sector.
Renewable Energy Focus, Volume 12, Issue 1, January-February 2011, Pages 38-40