Riding a wave of potential

Penny Hitchin

A 21st century challenge for the power industry is to harness the natural power of the sea on a sufficient scale to provide a stream of predictable and affordable low-carbon electricity.
Atlantis Resources’ 1 MW AR1000 tidal turbine at the EMEC in Orkney, Scotland Source: Atlantis Resources

Marine energy is a vast resource of great potential, but the technology for converting it into a usable format is in its infancy and much investment and development work is needed to bring it to market.

The European Ocean Energy Roadmap published in May 2010 by the European Ocean Energy Association (EOEA) set out generation targets of 1 per cent of European Union (EU) electricity generation (3.6 GW of installed capacity) by 2020, and 15 per cent (about 188 GW) by 2050. But meeting these targets would require rapid progress.

Since the roadmap was published, national goals have added 1.3 GW to the European target for 2020, which now totals 4.9 MW. Laboratories and R&D centres in Europe and further afield have now developed many prototypes and small-scale devices. Their transition to full-scale prototypes is underway as some of the technology gets nearer to market. But various hurdles must still be overcome to bring any of the range of concepts to maturity.

The challenges include installing and proving the operational viability of the devices in sea conditions, finding the necessary capital investment, establishing grid connections and developing a supply chain for manufacturing, installation, operations and maintenance, as well as establishing a regime for authorisations and regulation.

The term ‘marine energy’ is used to describe technologies at varying stages of development including tidal stream, tidal barrage, wave and ocean thermal energy conversion. Sites for the development of wave and tidal energy are dictated by climate and geography. The best European locations lie in the Atlantic arc along the west coasts of the UK, Ireland, France, Spain and Portugal. The UK domestic tidal stream resource represents around half of the European resource, and about 10″15 per cent of the known global resource.

Tidal energy comes from movements of large volumes of water in the sea: the entire water body from the surface to the seabed moves and water levels near coasts rise and fall in a regular and predictable pattern. Scotland’s Pentland Firth has one of the fastest tidal races in the world, with up to 3 million tonnes of water per second rushing to and from the Atlantic Ocean and the North Sea between mainland Scotland and the Orkney Islands at speeds of about 2 metres per second.

Developments in 2010″11

The European Marine Energy Centre (EMEC) in Orkney, Scotland, is Europe’s main centre for developing and commercialising ocean energy technologies. The centre provides grid-connected wave and tidal sites for testing prototypes. Public sector investment of about à‚£15 million ($23 million) has enabled EMEC, established in 2003, to become the world leader, and by 2011 it was self-financing.

Neil Kermode, managing director of EMEC, describes its role as “providing an entry point, a demonstration space which is helping generate the investor confidence needed to build the industry”. “There has been a dramatic ramp-up in the last couple of years,” he says. “It has taken longer to come to fruition than we had hoped, but now developers are coming from all over the world to the site.”

The Wave Energy Centre in Portugal provides strategic and technical support to companies, R&D institutions and public organisations. Smaller test facilities are based in Ireland, Norway, Denmark, the UK, Spain and France.

A 2011 report by energy business analysts Douglas-Westwood identifies the UK, Canada and the US as the three biggest markets for wave and tidal energy. Installations in 2011 are more than double those in 2010 and the report forecasts a total of 150 MW of capacity will be installed in 2011″2015, of which 110 MW will be in the UK.

Excellent wave and tidal resources, government funding, market mechanisms and site licensing make the UK the world’s current strongest market for wave and tidal energy. Trade association RenewableUK reports that by April 2011 the UK had an installed capacity of 3.4 MW of marine energy ” consisting of 1.31 MW of wave energy capacity and 2.05 MW of tidal stream capacity ” a 50 per cent increase from 2.4 MW the previous year.

The owner of the UK seabed is the Crown Estate. In a world first, in March 2010 it leased ten sites in the Pentland Firth and the coast of Orkney to developers of wave and tidal wave projects capable of generating 1200 MW ” split equally between wave and tide generation ” by 2020. An additional lease for a Pentland Firth site, with a potential of 400 MW in tidal capacity, was granted in October 2010. The Crown Estate’s leases for UK wave and tidal energy development now total 30.

But wave and tidal generation will require hefty investment to become a mainstay of Europe’s electricity supply. EMEC’s Kermode counts political will and investor patience among the industry’s key issues. “This is building a brand-new industry that we have never tried before,” he told PEi. “We are talking about big engineering jobs: complex machines operating in a harsh environment and we have to do good-quality engineering to prove it is investable.”

The last few years have definitely brought a growing appetite for backing marine energy devices, with utilities and power companies increasingly looking for investment opportunities, he says. Institutional and political support is vital, as developers go where grants, incentives and support are forthcoming. Support has included feed-in-tariffs, a range of support mechanisms for renewable generation, carbon price funding, and government and EU grants.

In November 2011, the UK Crown Estate slashed the level of financial guarantees required from wave and tidal customers, making it easier for small firms to enter the UK’s wave and tidal industry. Projects that have already won rights in the Pentland Firth and Orkney waters will have their parent company guarantees reduced from à‚£25 million to no more than à‚£5 million per project.

The European Commission has spent more than €55 million ($70 million) on ocean energy research over the last 20 years and ocean energy is one of the priorities of the current Framework Programme. The latest EU-funded scheme, the €9 million MaRINET project, led by University College Cork, is intended to provide access to specialist marine renewable energy testing centres across Europe for small developers.

Wave and tidal technology is evolving and rapidly maturing. This article now profiles some of the technologies. The ultimate market leaders, which set the industry standards and provide mainstay generation in the future, are likely to evolve from amongst them.

Wave power players

The thriving wave power market has three major players: Pelamis Wave Power, Aquamarine Power, and Voith Hydro Wavegen. Pelamis, which has been developing its wave energy converter since 1998, uses a hydraulic system to convert the movement of waves into electricity using electrical generators. A series of 4-metre-diameter tubes are connected to make the 180-metre-long ‘sea snake’.

Pelamis has raised à‚£40 million of development funding from a variety of financial and industry backers and has sold devices to utilities E.ON and ScottishPower Renewables. In October 2010, E.ON’s Pelamis P2 machine began generating to the UK grid at EMEC. A year later, the company was authorised to build a 10 MW commercial wave farm near the Island of Bernera in the Outer Hebrides. Up to 14 Pelamis machines will be installed within 10 km of the shore. Construction is targeted for 2015, when planned grid upgrades will be in place.

Swedish utility Vattenfall has formed a joint venture with Pelamis and Aegir Wave Power to develop a 10 MW wave farm in Shetland. Aegir hopes to have authorisation for construction by 2015.

Wave energy company Aquamarine Power‘s Oyster technology is designed to convert energy from near-shore waves into electricity. The first full-scale 315 kW Oyster 1 was installed at EMEC and grid-connected in 2009, when the company also signed a deal with SSE Renewables to develop up to 1 GW of wave farms. In 2010, Aquamarine and SSE Renewables were awarded a 200 MW lease option as part of the Pentland Firth and Orkney leasing round. In 2011, the company was awarded a 40 MW lease option for a proposed wave energy site on the Isle of Lewis.

The Aquamarine Power ” SSE Renewables joint venture is developing a 2 MW demonstration site at EMEC that will be expanded to 10 MW in 2012 and subsequently 200 MW. Installation of the second-generation Oyster 800 started in 2011 at EMEC. Oyster 2 will consist of three linked 800 kW wave power devices powering one onshore hydroelectric generator. Aquamarine plans to deploy its first commercial Oyster devices in 2013.

In 2000, Wavegen installed a Limpet wave energy plant on the island of Islay that has been delivering power to the grid for 10 years. In 2005 Wavegen was bought by Voith Hydro ” a joint venture of Voith and Siemens ” to form Voith Hydro Wavegen.

Wavegen’s core technology is an Oscillating Water Column (OWC). The device has no gearbox or pitching blades, but needs to be installed in a breakwater or similar structure. In November 2011, the first commercial full-life Limpet wave power plant went into operation in northern Spain. The €1.2 million Wavegen plant was bought by Ente Vasco de la Energàƒ­a (Basque Energy Board). The 300 kW wave power plant is built into a breakwater at the port of Mutriku and is designed to operate for 25 years.

Marine energy technology developer AWS Ocean Energy is testing a 1:9 scale version of its surface-floating wave power system in Loch Ness, Scotland. AWS wants to deploy a full-size prototype in 2012 and a pre-commercial demonstrator the year after. Subject to financing and planning consents, the company plans to have a 10 MW pre-commercial demonstration farm operating in 2014.

Ocean Power Technologies (OPT) is developing PowerBuoy wave power technology. In 2011, the US company tested the PB150 PowerBuoy off the Scottish coast. The WavePort consortium led by OPT aims to deliver a commercial-scale demonstration project: a PB40 PowerBuoy at a mooring site at Santoàƒ±a, Spain, that had previously been developed by OPT under a contract from Iberdrola.

In September 2011, Finnish utility Fortum and Swedish developer Seabased announced plans to build a €37.5 million full-scale demonstration wave power park in Sotenàƒ¤s, Sweden. Production of buoys, generators, substations and converters is underway with installation due to start later this year. The completed 10 MW wave power park of 420 buoys is scheduled for completion by 2015.

Fortum is also involved in the Finnish WaveRoller project. Installation of a 300 kW demonstration plant in Peniche, Portugal, is planned for this year. In November 2011, Fortum and French naval firm DCNS agreed to plan a joint feasibility study for a wave power demonstration project in France. Finnish company AW-Energy Oy has developed the WaveRoller for generating electricity from surge ocean energy. EU funding is contributing towards installing the demonstration plant in Portugal.

Finnish company Wello is developing the Penguin wave converter. Each unit is a 30-metre-long, 1600-tonne vessel held in place by three wires anchored to the seabed. The asymmetrically shaped hull captures rotational energy generated by its movement. Electricity is exported via a subsea cable. A five-year development programme has increased the size of the prototype. In the summer of 2011, a 500 kW Penguin built in Riga Shipyard, Latvia, was towed to Orkney, where it is due to be deployed early in 2012 for a year-long test programme at EMEC.

A working prototype of the Seatricity wave concept has been tested in the Atlantic Ocean off Antigua, and will be tested at EMEC. Seatricity plans to manufacture 50 devices to be installed in an array that will be linked to a pipeline to feed high-pressure seawater to a land-based hydro generating station. The 1 MW capacity plant is due to be operational in the spring of 2012.

European nations’ wave resources vary greatly according to the EU’s Aqua-RET project Source: Aqua-RET

The Wavebob energy converter (WEC) is an oscillating point absorber designed to convert wave energy into electricity. In 2009, Wavebob led a consortium awarded €5.1 million under the EU FP7 R&D programme to deploy a pre-commercial, grid-connected WEC off Portugal.

The Danish Wavestar concept has been in development for ten years, gradually being worked up to full scale. A 600 kW machine installed at Hanstholm in Denmark has been connected to the grid since February 2010. Wavestar says it aims to have its first series-produced 500 kW machine ready for sale in 2012 or 2013.

Wave Dragon is a floating, slack-moored energy converter that can be deployed in a single unit or in arrays. The first grid-connected prototype is deployed in Nissum Bredning, Denmark. A pre-commercial demonstrator is planned for Milford Haven in Wales.

Tidal power devices

Bristol-based Marine Current Turbines (MCT), founded in 2000, installed the world’s first offshore tidal turbine off the coast of Devon in 2003 and completed installation and commissioning of the 1.2 MW SeaGen in Strangford Narrows, Northern Ireland, in November 2008.

The 1.2 MW SeaGen tidal energy system in Strangford Lough in Northern Ireland Souce: MCT

MCT has formed partnerships with RWE npower renewables to develop the 8 MW Kyle Rhea project in Scotland and the 10 MW Anglesey Skerries project in Wales. The à‚£70 million, 10 MW Skerries scheme is for up to nine SeaGen turbines off Anglesey and commissioning is targeted for 2014″2015. The proposed à‚£40 million Kyle Rhea project is for four SeaGen devices installed between the Isle of Skye and the coast of Scotland generating 8 MW.

Norwegian company Hammerfest Stràƒ¸m develops tidal stream turbines and tidal power arrays. The main shareholders are Andritz Hydro, Statoil, Hammerfest Energi and Iberdrola. A Hammerfest Stràƒ¸m HS1000 1 MW tidal stream turbine was installed at EMEC in December. The HS1000 is based on a 300 kW prototype that has been generating in a fjord in Norway for eight years. Deployment of the HS1000 is scheduled to start this year in the Sound of Islay. UK subsidiary Hammerfest Stràƒ¸m UK has the lease to install 95 tidal turbines at Ness of Duncansby in the Pentland Firth by 2020.

OpenHydro, formed in 2005, is developing sites in France, Scotland and the Channel Islands. It opened its 2500 mà‚² European assembly facility at Greenore Port, Ireland, in 2007. In January 2011, Irish energy provider Bord Gàƒ¡is Energy became a shareholder in OpenHydro and the companies formed a joint venture focused on developing an Irish tidal farm. Also in January last year, OpenHydro sold an 8 per cent share to DCNS for €14 million and the firms agreed to collaborate on tidal energy projects. OpenHydro also has a €40 million contract with EDF for the Paimpol-Bréhat tidal farm in Brittany, France.

Atlantis Resources Corporation started developing free stream tidal turbine prototype designs in Australia. In mid-2007, investment bank Morgan Stanley became a shareholder. The following year Atlantis took over Morgan Stanley’s UK-based marine power business Current Resources Limited. During 2009, the Norwegian utility Statkraft became an equity investor, followed in 2011 by EDBI of Singapore.

In 2010, a consortium led by Atlantis Resources was awarded the rights to develop the 398 MW tidal site in the Inner Sound of the Pentland Firth. In late 2010, Atlantis sold control of the project to International Power GDF Suez (45 per cent) and Morgan Stanley (45 per cent), retaining 10 per cent. This MeyGen joint venture will install Atlantis turbines to generate 150 of the first 160 MW. The remaining 10 MW is to be used as a test array for TGL turbines.

Bristol-based tidal stream turbine developer Tidal Generation Limited (TGL) was formed in 2005 and became a wholly-owned subsidiary of Rolls-Royce in 2009. The TGL 500 kW concept demonstrator unit operating at EMEC has been generating since September 2010. TGL plans to replace the 500 kW device with its pre-production 1 MW device for 24 months of testing from mid-2012. TGL is aiming to install a 10 MW demonstration array in 2013/14 in the Inner Sound of the Pentland Firth as part of the 398 MW MeyGen project.

In November 2010, Hydra Tidal Energy started a two-year trial period of testing for its 1.5 MW Morild II floating tidal power plant off the Norwegian coast. In April 2011, Norwegian industrial company Dyranut took an 84 per cent interest in Hydra.

Saab started developing the Swedish Deep Green tidal energy technology in 2003 and four years later spun off new company Minesto Deep Green to bring the technology to market. Funding from Invest Northern Ireland and the Carbon Trust convinced Minesto to develop a trial site on the east coast of Northern Ireland. The ‘underwater kite’ tidal generator started tests in the Irish Sea in summer 2011. The company says its technology could unlock significant tidal resources as it can operate in low-velocity tidal streams. The plan is to have the first array of Deep Greens installed by 2016, generating 10 MW.

Commercial viability of the 1.2 MW Deltastream tidal stream device is being tested this year at Ramsey Sound, Pembrokeshire, in Wales. An estimated à‚£11 million is needed to manufacture and deploy the demonstration device. Renewable energy company Eco 2 is the main funder, with additional funding from Carbon Connections UK and support from the European Regional Development Fund.

CETO Wave Energy Ireland, a subsidiary of Australia’s Carnegie Wave Energy, has applied for a foreshore licence for a 5 MW commercial CETO demonstration off the coast of County Clare, Ireland. A 2011 project study was 50 per cent funded by the Irish government’s Sustainable Energy Authority of Ireland under the Ocean Energy Prototype Research and Development Programme.

Marine energy is at a critical and exciting stage in development. Various concepts for wave and tidal generation have been tested but a great leap forward is needed to get them to a scale and standard where they can be deployed in commercially viable arrays.

Investment and application will be required to achieve this, but the last couple of years have seen the engagement of utilities and other investors, which signals their intention to drive the technology to maturity. This will be essential if EU goals for future renewable generation are to be met.

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