Ocean Energy Explored

Marine current, wave and tidal energy is set to boom. Not only is interest and investment in the range of technologies growing, the engineering disciplines and testing facilities that support them are becoming more mature. With full commercial operations surely just around the corner, we explore the power of the deep.

By David Appleyard

A declaration by the UK government that the South West of the country is to be designated the first Marine Energy Park suggests that, while ocean energy technologies are largely in early development if not infancy, their place in the future global energy mix is all but assured.

According to a statement from the UK’s Department of Energy and Climate Change, the South West Marine Energy Park will stretch from Bristol through to Cornwall and as far as the Isles of Scilly, creating a collaborative partnership between national and local government, Local Enterprise Partnerships, the universities of Plymouth and Exeter, and industry. The aim of the partnership will be to speed the progress of marine power development.

Choosing this region makes sense, as it is already home to many successful marine/tidal developers and developments. For instance, Cornwall is the location of Wave Hub, a grid-connected offshore facility for testing wave energy technologies. It holds a 25 year lease of 8 km2 of sea bed about 16 km off the north coast of Cornwall and provides shared offshore infrastructure for the demonstration of arrays of wave energy devices. The 12 ton hub is linked to the UK’s electricity transmission grid via a 25 km cable operating and is permitted for up to 20 MW of capacity across its four berths, which are available to lease.

Deployed in the summer and autumn of 2010, Wave Hub can be upgraded to about 50 MW once components for operating the cable at 33 kV have been developed, its backers claim.

Commenting on the move to enhance the region’s role in marine development, Claire Gibson, Wave Hub’s general manager, said, “Wave Hub is a cornerstone of the new Marine Energy Park, and we look forward to playing our role in accelerating the commercial development of marine renewables.”

The move followed a late 2011 agreement between Falmouth Harbour Commissioners and owners of the UK’s seabed The Crown Estate to create a wave energy “nursery” test site in Falmouth Bay on the south coast of Cornwall.

This FabTest site has also been issued a five year license by the Marine Management Organisation, allowing the mooring of marine energy converter devices. Although not electrically connected, FabTest will enable up to three device developers to investigate structural integrity, response behavior, mooring and umbilical behavior, subsea components, monitoring systems and deployment procedures in moderate sea conditions before deploying their devices in more energetic offshore conditions.

“FabTest will provide an opportunity to boost our already world-class research in marine renewable energy, including assessing the impact of the technologies on the marine habitat and the development of improved engineering solutions, prediction and modelling techniques,” says Dr. Lars Johanning, senior lecturer in renewable energy at the University of Exeter, which will manage the center. “FabTest complements the growing marine energy assets and expertise we have in the South West region. It has been designed as a stepping stone to Wave Hub and will help device developers on the critical path to commercialization.”

FabTest has also been welcomed by Plymouth University, which is building wave and tidal tank testing facilities that will be unique in the UK when they open, scheduled for this year.

And in May 2011, plans for an offshore renewables innovation center were released by UK Business Secretary Vince Cable. The Offshore Renewable Energy Catapult, announced in February 2012, will focus on the development of offshore wind, wave and tidal technologies through its headquarters in Glasgow and operational center in Northumberland.

Commenting on the creation of the South West marine energy zone, energy minister Greg Barker said, “This is a real milestone for the marine industry and for the South West region in securing its place in renewables history. The South West can build on its existing unique mix of renewable energy resource and home-grown academic, technical and industrial expertise. Marine power has huge potential in the UK not just in contributing to a greener electricity supply and cutting emissions, but in supporting thousands of jobs in a sector worth a possible £15 billion to the economy to 2050.”

A 500 kW tidal turbine manufactured by Irish firm OpenHydro began operating in Brittany, France, in August 2011. Based on successful testing of this unit, two 16 m-diameter units are to be installed off the coast of Paimpol-Brehat in the summer of 2012.

Of the eight full-scale wave and tidal energy devices installed worldwide, seven are in the UK. And in the past seven years, £100 million (US$159.4 million) has been invested in the south west marine energy industry, creating world-leading research and demonstration facilities. Other areas, such as in the Pentland Firth and Orkneys, location of the European Marine Energy Centre (EMEC), are also working on developing a marine energy park based on regional strengths and activities.

An international resource

It is not only British companies that are benefitting from the UK’s drive toward dominance in the marine energy sector.

For instance, Ocean Energy Limited, an Irish company, is working with Wave Hub to deploy its technology later this year. Cork-based Ocean Energy, in collaboration with partner Dresser-Rand, expects to deploy a full scale device by the end of this year, having tested a quarter scale prototype of its OE Buoy in Galway Bay for three years. Wave Hub will match fund some of Ocean Energy’s deployment costs up to £1 million ($1.6 million), after a competition last year for device developers able to deploy in 2012. This includes the cost of securing a marine license and installation of moorings and deployment.

Ocean Energy, whose OE Buoy uses the oscillating water column principle to generate power by forcing air though a turbine, says it will consider fabricating its 1.5 MW device locally. Dresser-Rand developed and patented the HydroAir turbine – a variable radius turbine that uses a combination of stainless steel, aluminium and reinforced composites to resist corrosion.

Similarly, USA-based Ocean Power Technologies has signed a commitment agreement to deploy its PowerBuoy device at Wave Hub.

More recently, in late December 2011, a 1 MW tidal turbine was installed off the Orkneys by Hammerfest Strom AS, a company partly owned by Iberdrola, Andritz Hydro and Statoil New Energy. In March 2012, Andritz increased its stake in Hammerfest Strom to 55.4% from 33.3%.

The device, an HS1000 that has a 30 m rotor diameter, is to be part of one of the world’s first tidal power arrays in the Sound of Islay, under development by Scottish Power. With machines due to be installed during 2013 to 2015, the company’s goal to develop this 10 MW tidal array received planning consent from the Scottish government in March 2011, and a prototype device has been operating in Norway for more than six years.

The device underwent a test period to confirm its performance and reliability, in preparation for larger scale deployment. It is expected that the machine will be fully operational as HRW goes to press.

Keith Anderson, chief executive of ScottishPower Renewables, said, “This is a major milestone in the development of tidal power technology in Scotland and for the tidal power industry across the world. We anticipate using this turbine as part of our project in Islay, which remains the only consented tidal array project in Scotland. Beyond this, we have ambitions to use this turbine as part of even larger scale projects in the Pentland Firth, which we are currently investigating.”

Meanwhile, in January 2012 Alstom and SSE Renewables signed a joint venture agreement to develop the Costa Head Wave Project of up to 200 MW north of mainland Orkney. The companies say they will work to obtain the necessary permits and intend to populate the site with AWS-III wave energy converters, under development by AWS Ocean Energy Ltd., in which Alstom acquired a 40% equity share in June 2011. AWS is also backed by Shell Technology Ventures Fund 1 and the Scottish Investment Bank.

With the plans envisaging an initial phase of about 10 MW, the Costa Head site is located in water depths of 60—75 m about 5 km north of Orkney.

The AWS-III converter is a floating device with a capacity of 2.5 MW. The AWS-III technology consists of an array of flexible membrane absorbers that use wave action to compress air, which is then forced through a turbine. A 1:9 scale model was tested in Loch Ness in 2010. Full scale component testing will commence in 2012 with the support of the Scottish Enterprise-administered WATERS fund, with a full scale prototype planned for deployment at EMEC in 2014.

SSE Renewables received exclusive development rights to the Costa Head site from the Crown Estate in 2010 and with partners is currently developing half of the 1.6 GW of wave and tidal sites leased by The Crown Estate as part of a commercial leasing program for marine energy projects.

With its venture into the marine energy sector, Alstom joins an illustrious group. Just this February, German giant Siemens acquired a majority stake in Marine Current Turbines Ltd., a UK-based company that develops tidal stream turbines. This latest development followed a November 2011 move in which Siemens increased its stake in the company to 45%, having initially acquired a stake in February 2010.

A Pelamis project undertaken by E.ON has been grid connected at the European Marine Energy Centre for more than a year and was joined by a second unit delivered to the site in November 2011.

In November 2008, MCT implemented a commercial scale demonstration project with its 1.2 MW twin rotor SeaGen device in Strangford Lough in Northern Ireland, producing more than 3 GWh to date.

Further projects are at the planning stage, including 8 MW Kyle Rhea off Scotland’s Isle of Skye and 10 MW Anglesey Skerries in Wales, under development with project partner RWE npower renewables. The scheme consists of up to nine turbines in an area between the Skerries group of rocks and islands and Carmel Head about 1 m off the Anglesey coast. Subject to securing planning and financing for the project, MCT and RWE npower renewables are targeting 2014-2015 for the start of commissioning.

MCT is also working with Minas Basin Pulp & Power to deploy a SeaGen tidal system into the FORCE facility in Canada’s Bay of Fundy. In addition, MCT has an approval for a lease from The Crown Estate to deploy a 100 MW tidal farm off Brough Ness, on the southernmost tip of the Orkney Islands.

The news followed a recent report prepared by environmental consultancy Royal Haskoning that finds the machine in Strangford Lough has had no major impact on the Lough’s marine life.

Commenting on the findings, David Erwin, chairman of the SeaGen Scientific Group and Stakeholder Liaison Group, said, “This is the most comprehensive study of the environmental impact of marine energy devices undertaken anywhere in the world. I was always confident that SeaGen could operate without any significant impact, and I’m delighted that the results of five years’ painstaking work by some of the world’s most-respected experts have shown this to be the case.”

Many other engineering players are looking to secure access to the EMEC testing facilities. For example, Dutch offshore energy company Bluewater Energy Services is to occupy a tidal demonstration berth at the Fall of Warness test site for demonstration of its full-scale floating tidal energy converter, BlueTEC, which is based on vertical axis turbine technology. And in October 2011, Japan’s Kawasaki Heavy Industries Ltd. announced it is launching an ocean tidal generation system, having been selected by the New Energy and Industrial Technology Development Organization as general contractor for a demonstration project off the coast of Okinawa. Kawasaki will work with Okinawa Electric Power Co. and Okinawa New Energy Development Co., with an eye to full-scale testing at EMEC.

Cementing the UK’s leadership position

In February 2012, a report by the UK’s Energy and Climate Change Select Committee determined the UK could become a leading exporter of wave and tidal power equipment and expertise, but only if the government adopts a more visionary approach to developing marine renewables. According to the report, wave and tidal stream energy have the potential to supply 20% of the country’s current electricity demand and in a more reliable and predictable form than some other renewables.

The UK could also export goods and skills as markets emerge around the world, the committee believes, adding that attracting investment will be key and noting that investors want a stable and consistent policy regime to give them confidence.

Acknowledging that such technologies could play an important role as part of a low-carbon energy mix in the future, the analysis nonetheless acknowledges their high cost and concedes that their present state of development means they are unlikely to make much, if any, contribution before 2020.

The priority over the next decade must be to focus on reducing the cost of marine renewables, the committee concludes, observing that potential obstacles fall into three categories: bureaucratic, financial and practical.

Although it is still early days for marine renewables, the longer-term benefits associated with developing a thriving wave and tidal industry in the UK are significant. An overly cautious approach may allow other countries to steal the UK’s lead. There is increasing interest in marine renewables around the world, with markets beginning to emerge in Canada, USA, Korea and New Zealand, among others. There is also scope for supplying physical components of marine devices to these markets, as well as providing specialist skills and expertise.

Tim Yeo MP, chair of the committee, said, “Britannia really could rule the waves when it comes to marine renewable energy. We are extremely well-placed to lead the world in wave and tidal technologies, which could potentially bring significant benefits in manufacturing and jobs, as well an abundant supply of reliable low-carbon electricity. A more visionary approach from the DECC could help to boost confidence and drive the pace of development.”

The UK’s Renewable Energy Assoc-iation welcomed the thrust of the report but questioned the logic of its targets for cost reduction and deployment. REA said that while cost reduction is critical, setting overly stringent targets (which fail to account for the volatility of fossil energy prices) is not helpful as it is hard to foresee at this early stage how the range of innovative devices in the pipeline will develop. And, they add, while deployment targets help drive ambition, this is a trait with which the industry is already brimming over – what it needs is better access to finance, they argue.

Meanwhile, RenewableUK’s Director of Policy Dr. Gordon Edge said, “The committee’s report contains important recommendations that, if implemented, will help push the marine energy industry toward becoming a major part of our electricity generation system. In particular, we welcome the committee’s recognition that any failure to help the industry live up to its promise could lead to other countries stealing the UK’s current global lead. Certainty is the watchword for securing the investment marine energy will require to become a major power source. We don’t yet have that certainty, and the committee’s call for long-term clarity on government support for marine energy is timely.”

Utility engagement

The potential opportunities for large-scale generation are indicated by a September 2011 deal between New Jersey, USA-based OPT, leaseholders of one of the Wave Hub bays, and Lockheed Martin. The two say they intend to collaborate on utility-scale PowerBuoy deployments for an Oregon wave power project at Reedsport.

Under the terms of the alliance, Lockheed Martin will provide design, manufacturing, system integration and supply chain management expertise to enhance OPT’s PowerBuoy technology.

“OPT’s engineering and innovation efforts for the utility market are focused on improving power conversion efficiency, reliability, manufacturability and lowering the costs of marine operations and maintenance,” said Charles F. Dunleavy, chief executive officer. “We will be rolling out the PB150 PowerBuoy product, our latest utility market offering, over the next few years and will also leverage this experience for the next generation of the PowerBuoy, our 500 kW device that is currently under development.”

It is intended to be the first of a 10 buoy wave power station with a peak generating capacity of 1.5 MW based on modular, ocean-going buoys. This latest Lockheed deal followed an August announcement of an autonomous PowerBuoy designed and manufactured under the U.S. Navy’s Littoral Expeditionary Autonomous PowerBuoy (LEAP) program for coastal security and maritime surveillance. The LEAP PowerBuoy structure, incorporating a unique power take-off and on-board energy storage system, is significantly smaller and more compact than the company’s utility PowerBuoy and was deployed in August 2011 by a U.S. Coast Guard vessel about 33 km off the coast of New Jersey.

In May of that year, OPT announced the commencement of ocean trials of the first of its new generation utility scale PowerBuoy device, the 150 kW PB150, built about 53 km from Invergordon, off Scotland’s northeast coast.

OPT says it is involved in other planned projects in North America, Australia, Japan and Europe that would use the PB150, and the company has two PowerBuoys operating in separate oceans, a grid-connected 40 kW PowerBuoy in Hawaii and the one in Scotland.

Another utility power project currently under development comes from Irish technology firm OpenHydro, which in August 2011 deployed its first 500 kW tidal turbine in Brittany, France, in conjunction with French utility Electricite de France, following assembly of the machine at DCNS’ shipyard in Brest. DCNS acquired an 8% stake in OpenHydro in January 2011 for €14 million ($18.6 million), following up with a further 3% acquisition in the November.

With a three-month testing period completed late last year, the first two 16 m-diameter tidal turbines are due for installation off the coast of Paimpol-Brehat this summer and the last two by the end of 2013.

James Ives, chief executive of OpenHydro, said, “We are delighted to be working with EDF on what is set to be the world’s first large-scale, grid-connected tidal energy farm and France’s first offshore tidal installation. EDF’s vision to develop this exciting project places France and EDF at the forefront of this new form of renewable energy generation.”

The site will see the 2 MW array deployed on the seabed at a depth of 35 m. The €40 million ($53.3 million) Paimpol-Brehat tidal farm project was initiated by EDF in 2004, and work began in 2008.

Also in January 2011, Irish energy group Bord Gais Energy committed up to €2 million ($2.7 million) to OpenHydro as part of its plans for Ireland’s first tidal energy farm, and the company now has a project portfolio spanning the USA, Canada, France, Scotland and the UK’s Channel Islands with utility partners including EDF, NovaScotia Power and SSE Renewables. In 2010, OpenHydro, in conjunction with SSE Renewables, was awarded license rights by The Crown Estate to develop a major 200 MW tidal farm in the Pentland Firth, off the northern coast of Scotland.

Another example of utility engagement comes from E.ON, whose Pelamis project has been grid connected at EMEC for a year and more. The E.ON machine was installed in October 2010, and since then Pelamis has implemented a progressive testing program in increasingly energetic sea conditions.

More recently, in November 2011, this machine was joined by a second P2 delivered to EMEC under a supply contract with ScottishPower Renewables. Constructed at the Pelamis headquarters in Leith, Edinburgh, this device will operate in tandem as a two-machine wave farm with the E.ON device. Information gathered from the trials will be used to support the development of commercial-scale projects currently under development by ScottishPower Renewables and E.ON off the coast of Orkney.

Both devices are rated at 750 kW.

Deployment of the second machine at EMEC followed an agreement with The Crown Estate to develop a 10 MW wave farm at a site 1-10 km off the west coast of Lewis in the Outer Hebrides near the Island of Bernera. Construction is planned for 2015.

In addition to its activities with E.ON and Scottish Power, in May 2011 Aegir Wave Power, a joint venture between Swedish utility Vattenfall AB and Pelamis, secured a similar Crown Estate lease for a 10 MW project off the south west of Shetland. According to a spokesperson, Pelamis is working with utility Energias de Portugal with a view to executing long-term ambitions to re-enter a site of the coast of Portugal, site of early testing of three P1 devices that were decommissioned in 2008.

Outlook for marine tidal

According to Siemens, the worldwide potential for power generated by tidal plants is about 800 TWh annually, 25% more than the total power demand of Germany and equivalent to 3-4% of current global power consumption. Coastal regions with strong tidal currents like those in the UK, Canada, France and East Asia offer major potential for utilization of this technology, they add. Meanwhile, ocean power is emerging, with strong growth rates driven by global climate change commitments. Through to 2020, the company anticipates double-digit growth rates for the ocean power market.

Given such a vast resource base, it is evident why marine and tidal current renewables are attracting significant investment. But alongside the steadily growing engagement from the engineering majors and utility groups, there are others. For example, EMEC will collaborate with its marine energy counterparts from the Ocean University of China in Shandong Province under a partnership announced in December 2011. Based in the eastern coastal city of Qingdao, the university has reached a deal that will see EMEC staff assist to develop a wave test center in Shandong.

Amanda Pound, marine renewable services manager for A&P Falmouth, explains that with its nexus of natural resources, government engagement and industry – with its long history of maritime achievement – the UK offers a unique proposition for the marine energy sector. However, Pound also argues that for the UK to maintain its global lead it must continue to develop its nurturing position and foster a close alliance between industry, academia and government.

David Appleyard is chief editor of HRW-Hydro Review Worldwide.

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