A spate of small wave power schemes is now under development that could eventually result in the widespread commercial production of electricity utilising the power of waves, writes Neil Ford
Wave power has long been mooted as one of the most attractive forms of renewable energy. The movement of the waves is far more predictable than wind and so in theory wave power should offer a more reliable option, particularly for on-grid power generation. Yet while turbine manufacturers are currently enjoying a boom on the back of the development of hundreds of new wind farms in Western Europe and elsewhere, research into wave energy has largely remained the preserve of academic institutions rather than power companies.
The obstacles to the development of commercial wave farms are well known in the renewable energy industry. Water covers 70.8% of the earth’s surface but only a relatively small proportion of this is likely to be suitable for producing electricity from waves, partly because it would not be economically feasible to build transmission lines from the centre of oceans thousands of kilometres onshore. In addition, the hydrokinetic power produced by waves is often greater closer to land than far out to sea, although this is also an advantage as it means that the optimum wave energy locations are closest to power markets.
Difficulties in developing the technology required to turn the power of waves into electricity have perhaps played the biggest role in holding back the emergence of the industry. Yet some of the wave power technologies now under development around the world are operating on a commercial basis. Critics argue that they are only commercially viable with financial subsidy but the same could be argued of most other forms of renewable energy, including on-grid wind power.
The UK is one of the most attractive locations for wave power production anywhere in the world. An intensive British research and development (R&D) programme was launched in the 1970s in response to higher oil prices but was cancelled in 1982 after the oil price collapsed. A lack of government support also prevented the UK from taking the lead on wind power, allowing Denmark and Germany to establish successful and growing wind energy industries that provide thousands of highly skilled jobs and generate hundreds of millions of dollars in export earnings.
As a result, the British government hopes that the same mistakes will not be made on becoming the world leader on wave power technology. One of the biggest government backed schemes is a £28M ($55M) Wave Hub project that is being developed 16km off the Cornish coast, where dozens of different technologies can be tested over many months, with up to 20MW of generating capacity connected to the national grid via a dedicated transmission line. If completed, this will be the biggest wave farm in the world to date [see IWP&DC November 2007 for an in-depth report on the project].
The project is being driven by the South West Regional Development Agency (SWRDA), which is investing £21.5M in the venture, with a further £4.5M being providing by the UK’s department of trade and industry. Four participating companies have signed agreements to date: Ocean Power Technologies Ltd, Fred Olsen Ltd, Oceanlinx and WestWave, which is a consortium of E.On and Ocean Prospect Ltd that will test ocean-power-delivery’s Pelamis technology. Each company will be granted a lease over 2km2 of maritime territory for between five and ten years.
When Oceanlinx signed its investment agreement last year, the general manager of the Wave Hub Project, Nick Harrington, said: ‘Oceanlinx has a proven technology that is sufficiently advanced to take advantage of the unique facilities that Wave Hub will provide and the company’s involvement reinforces Wave Hub’s status as a project of international significance.’ SWRDA predicts that the project could generate £76M a year for the regional economy, helping to achieve Southwest England’s target of producing 15% of its electricity from renewable sources by 2010, and eventually providing the basis of a large wave power industry in the region.
However, in April, the SWRDA announced that the first electricity will not be supplied by the Wave Hub until spring 2010, one year later than planned. Harrington, said: ‘We have reached the end of the tender process for the design and construction of Wave Hub and are disappointed that we have had to withhold the award of the contract. However, we were not content that the two tenders received…offered sufficient value for money. We will now use the additional time available to us to review the procurement process and the detailed design to establish the most cost effective way of delivering the project. We aim to complete this review within the next three months.’
While the current high price of oil and gas should act as an incentive to the development of hydrokinetic technologies, there are some signs that it could have a negative impact in the short term. Harrington commented: ‘The $100 plus cost per barrel of oil has led to a boom in oil and gas exploration which has increased substantially the cost of the equipment needed to install Wave Hub. Volatile markets have also seen significant increases in the cost of copper which has increased the cost of the cable that will be laid between Wave Hub and the mainland. Nevertheless, we are still ahead of the game with Wave Hub. We secured the necessary consents for the project back in September – the first region in the UK to do so.’
Another major R&D facility is provided by the New and Renewable Energy Centre (NaREC), in Northumberland, off the northeast coast of England. NaREC’s aim in the hydrokinetic sector is to give ‘the emerging marine renewables industry the support it needs to transform winning concepts into commercial successes’. The centre provides both inventors and investors with technical expertise and other support, including:
• In house prototype development facilities for both wave and tidal technology.
• Mechanical and electrical design engineering and procurement.
• Electrical engineering consultancy and support for power conversion and drive train development.
• Complete system testing from marine environment to grid connection.
• Resource and feasibility assessment and consultancy.
• Market analysis and research.
• Project management, funding and investment coordination.
The UK has also been chosen as the location for the European Marine Energy Centre, which is based in the Orkney Islands, off the north coast of Scotland. The centre will see four Pelamis units brought on stream by the end of this year, with each unit consisting of four 40 metre long steel tubes and resembling a giant caterpillar being moved up and down by the waves. The action of the waves in each tube drives fluid, which then powers generators. While most wave power systems have relatively small generating capacities, a new 3 MW Pelamis is now being tested. It is hoped that large amounts of on-grid electricity could be produced by deploying the Pelamis in large numbers.
Private companies are also investigating large scale wave power projects. In January, British firm Trident Energy announced that it will test its Direct Energy Conversion Method (DECM) in the North Sea, off the coast of Suffolk this year. The DECM varies from many other wave power units under development in that it has only one working part, and no hydraulic equipment or air compression is required. Floats placed in the sea are used to drive linear generators, resulting in the immediate generation of electricity. Trident promotes the system on the basis of its simplicity. While the company is still a long way from deploying the DECM in large numbers, it has proposed the eventual development of a £200 million ($395 million) wave power scheme utilising the DECM.
Such investment by the private sector would be far less likely without government financial and technical backing for hydrokinetic energy. In addition, the UK and European Union mandatory targets on renewable energy production indicate that there should be a market for any electricity produced by such schemes. Injecting even an element of commercial reality into technologies that are still widely considered to be at the research stage should help to bridge the gap between the academic world and the power sector.
The first shoots of an economically significant British wave power industry are already emerging and some new designs could be tested in other countries. Four Pelamis units may be trialled at the Aguçadora Wave Park in Portugal, which – with its Atlantic coastline – shares some of the UK’s wave power potential. Infrastructure allowing eventual generating capacity of 72.5 MW is to be provided at the park, which the Portuguese government hopes will attract investment of €70M.
The Portuguese Association of Renewable Energies (APREN) predicts that wave energy ‘will have a very strong relative weight in the second half of the next decade; it could even reach 1000MW of installed capacity’. In neighbouring Spain, power company Iberdrola agreed in mid-June to proceed with the Oceantec wave energy scheme in the Basque region. The firm’s equity investment offshoot Perseo is already active off the Orkney Islands and now intends to invest $9M in testing its own wave power units in Spanish waters, although no details of likely generating capacity have yet been released.
Another country with a long Atlantic coastline is also being targeted by private sector investors. In March, Irish firm Wavebob and Norway’s Vattenfall unveiled ambitious plans for 500 MW of wave power capacity to be installed off the coast of Norway. The first 50 MW tranche is scheduled to come on stream by 2012 but it remains to be seen whether the Norwegian government will offer sufficient financial incentives to make the proposals a reality. The vice president for research and development at Vattenfall, Lars Strömberg, concedes that the project would be impossible without subsidy. Given that both subsidised capital investment and feed-in tariffs or carbon credits would be required, it appears that the plans are an aspiration rather than a concrete proposal.
Another company with international ambitions is one of the investors in the Cornish Wave Hub, Australian firm Oceanlinx, which has six test projects under development: two in Australia, at Portland in Victoria and Port Kembla in New South Wales; two in the United States; one in the UK and another in Namibia. Its Denniss-Auld turbine produces power that can either be converted into electricity or used to desalinate sea water. In most cases, the company has sought to create partnerships with investors or power companies in the host country.
In Namibia, for instance, Oceanlinx has signed a power purchase agreement (PPA) with private power company Southern African Electricity Company (SELCo) for all power produced by a single 1.5 MW wave power unit, with a view to providing ten units in the longer term. David Weaver, Oceanlinx’s non-executive chairman, says of Namibia: ‘It’s a very, very good wave climate. It’s quite a stable, relatively wealthy part of Africa. Tourism is big, so they want to be known for protecting the environment’. Electricity is expected to be supplied to the town of Keetmanshoop from 2009 but the Namibian government is also interested in the desalination technology on offer because Namibia is the driest country in Sub-Saharan Africa.
Oceanlinx’s most recent project is in Mexico. In June, the country’s federal power utility Comisión Federal de Electricidad accepted an application to develop a pilot 750kW project offshore of Baja California, using the company’s Denniss-Auld turbine. A spokesperson for CFE commented: “If the results are as expected, the next step will be made from the pilot installation to a commercial wave plant.”
Also active internationally is Renewable Energy Holdings (REH), which revealed in March that it had followed up on its CETO prototype by testing the CETO II and III models off the coast of Western Australia. The British company revealed that the units were performing as expected and the test programme is expected to be completed by the middle of next year. REH has signed a deal with an offshoot of energy giant edf, Energies Nouvelles SA, to deploy the CETO unit at several sites in the northern hemisphere from next year, although no generating capacity has been given, either for likely projects or for the individual wave power units.
The company advertises the CETO II as the first wave power converter to sit on the seabed, where it is protected from storms and has no impact on the visual environment. In a statement, REH adds: ‘Unlike other wave energy technologies that require undersea grids and costly marine qualified plant, CETO requires only a small diameter pipe to carry high pressure seawater ashore to either a turbine to produce electricity, or to a reverse osmosis filter to produce fresh water.’
As reported in January’s issue of IWP&DC, a major breakthrough was made in North America when the United States Federal Energy Regulatory Commission (FERC) awarded its first hydrokinetic power licence to Finavera Renewables Ocean Energy Ltd. Last year FERC cut back its administrative requirements for small scale renewable energy projects, allowing Finavera to finally get the go ahead for its 1MW Makah Bay project, which is being developed in conjunction with the Makah Indian Nation just under two nautical miles off the coast of Washington State.
Finavera suffered a setback in November last year when one of its AquaBuOY 2.0 units sank off the coast of Oregon, after a leak caused a bilge pump to malfunction, thereby causing the entire unit to sink. Nevertheless, the company is in the process of deploying a range of AquaBuOY units in the US, Canada, Portugal and South Africa. Each AquaBuOY is a 25m long tube that sits vertically in the water and bobs up and down to propel a turbine. In March, FERC signed a joint agreement with the state of Oregon to speed up administrative procedures for wave power projects, including Finavera’s schemes, of less than 5MW generating capacity that are tested in the waters off the state’s Pacific coastline.
The huge variation in the design of the wave power units currently being tested highlights increased interest and confidence in the commercial production of electricity from waves. However, it also underlines that wave power production is still at a fairly early stage of development, with much more R&D required before large scale projects can be developed. There are currently about 30 to 40 wave power systems being tested and it seems likely that the vast majority of these will be discarded at some stage over the next decade, whether on technical or economic grounds. Yet it remains to be seen whether one model will come to predominate or whether different units will be best suited to different environments.
Most analysts put the wave power sector at 15-20 years behind the wind power industry in terms of development. However, a report in June by Triodos Bank of the Netherlands, which specialises in ethical banking, concluded that there is not such a big gap between the development of wave and wind energy. Matthew Clayton, the operations director of Triodos Renewables, said: ‘Marine power is a maximum of five years behind wind. The appetite is there, the market is there, the growth will be surprisingly fast.’ The findings are based on UK financial support for the industry, which is twice as high per unit of electricity as that afforded to the wind power sector.
While the most efficient wave power units produce electricity at roughly double the price of wind turbines, the technology’s proponents argue that wave power is half the cost of wind power when the latter was at the same stage of development. It is therefore hoped that wave power will enjoy the same benefits in terms of falling production costs as the wind power sector. About 60% of the world’s population lives less than 60km from the sea, so there are certainly benefits to be gained in terms of cutting transmission losses and costs but with so much unproven technology on offer, the battle for wave power has only just begun.
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Although wave power technology is being trialled in an increasing number of countries, there is still relatively little information about the distribution of global resources. However, a study by British consultants Baird & Associates in May reported that Chile has the greatest wave power potential. It concluded that the country could satisfy around 25% of its power requirements from wave energy without unbalancing the generation mix. There is already some indication that the country’s totally untapped wave resources could attract investment in the near future. The government of Chile passed new energy sector legislation in March that requires power utilities to source 5% of their electricity from renewable energy schemes by 2010, increasing gradually to 10% by 2024.