With a maximum output of 20MW, the Wave Hub will produce enough electricity to power 7500 homes, or around 3% of Cornwall’s domestic energy requirements. It may not seem much by today’s standards when compared to new, centralised power generation infrastructure, but the approval of the scheme marks a huge leap forward in the development of renewable power, not just in the UK, but also as a showcase for wave power technology that is set to attract the attention of developers the world over. Funding for the project has already been approved by the South West of England Regional Development Agency (SWRDA).

To appreciate why Wave Hub is so crucial to the development of renewable energy technologies – and importantly, to the south west – you need go back no further than two years ago when, in February 2005, a Summary Business Case published by Arthur D Little pinpointed exactly what the scheme means for renewables’ development in the UK and as a benchmark for the technology worldwide. ‘Wave Hub is the only proposal at an advanced stage to support deployment of arrays of different [wave energy converter] devices in the world,’ it said. ‘This concept can play a significant role in developing an international industry, while ensuring UK dominance in the market. Consequently, it is in a unique position to provide the real basis of a real competitive strength for the UK.’

It went on to stress the importance of the scheme as a means of bridging the gap between conceptual devices and commercial exploitation of the technology. ‘Wave Hub addresses the support gap between initial devices, typically less than 2MW, and the arrays of several devices that will be required for commercial viability.’

It was music to the ears of SWRDA, which has already approved the UK£28M (US$57M) funding needed to build the turnkey project. The Department for Business, Enterprise and Regulatory Reform (DBERR) has committed UK£4.5M (US$9.2M) towards the cost and SWRDA has already invested in excess of UK£2M (US$4.09M) to get it to its present stage.

Spurred by the south west region’s apparently ideal conditions for such a development – it has been identified as having considerable potential for offshore energy generation, because it has a good wave and tidal stream resource, is relatively accessible, and is subject to less extreme weather conditions than other parts of the UK – SWRDA is keen to get the Hub properly under way.

Tidal stream energy is already being generated in the region at a 300kV demonstration turbine in the Bristol Channel offshore of Lynmouth and the Hub is seen as a further response to developers’ needs in their quest to find similar opportunities. The world’s first offshore tidal energy turbine was built on the seabed, about 1.5km offshore of the popular tourist resort, in 2003.

A feasibility study conducted by Halcrow and Global Marine Systems for SWRDA identified an offshore site close to the Cornish town of Hayle as the most suitable location on the county’s north coast to construct Wave Hub. It is hoped it will act as a magnet for further development of wave power technology in the region, by providing the necessary infrastructure for several different companies to install their own designs of wave energy converters (WECs). Marine conditions are favourable, and the town and its environs already have much of the necessary onshore infrastructure to receive power cables from the seabed in order to connect to the National Grid.

In June of last year, Halcrow, which is acting as project manager for SWRDA in the matter, submitted proposals for the project to the (then) Department of Trade and Industry (DTI). In his letter of submission, project manager Alan Taylor laid out the main points supporting construction of the Wave Hub. It meets an identified market need, would substantially reduce the costs of consents and construction, and reduces the project risk inherent in such undertakings to individual developers and their investors arising from Environmental Impact Assessments, consents and the potentially inhibitive costs of grid connection. It will also assist in the development of an entire new industry associated with renewable energy in the south west, it maintained.

Remarkably, perhaps, the scheme has been relatively fast in coming to the fore, compared with some key wave and tidal renewable plans, not least of which is the long-standing proposal for a barrage across the Severn Estuary. In the case of the Cornish project, a number of engineering options were considered by developers, based on what is technically sound and achievable, has minimum environmental impact, is cost-effective and does not present significant safety and operational issues. The resulting preferred option features a ‘wet hub’ on the seabed, linked to the mainland by a subsea cable. The hub will consist of a cable termination and distribution unit connected to six underwater power connection units, while these, in turn, will be connected to wave energy devices on or just below the surface.

Project concept

The Wave Hub concept is to build an electrical grid connection point – a socket – some 10 miles (16km) offshore into which a number of WECs can be connected. The intention is to provide a well defined and monitored site with electrical connection to the onshore electricity grid, greatly simplifying the process that would otherwise have to be untaken on a project-by-project basis by individual developers of WECs. There’s another key benefit: all the underwater equipment is known technology and has been proven in the oil and gas industry.

The Wave Hub scheme can be split into three constituent parts. The first of these consists of a termination and distribution unit, which is attached to power connection units, enclosed in a protective casing and anchored to the seabed in around 50m of water. Second, a single 33kV-30MVA cable running from the Wave Hub to the shore will be buried where possible and suitably armoured where the seabed is rocky. The cable will be buried into the beach close to Hayle and taken through the sand dunes to a substation site by means of directional drilling. Finally, a substation, to be constructed at a former power station site in Hayle itself will connect the cable to existing power lines.

The WECs themselves, either floating, semi-submerged or fixed to the seabed, will connect to the Hub. When the project is finally operational, the area of the sea occupied by the WECs and a buffer zone around them will be around 8km2.

Expected benefits

SWRDA has been keen to promote the scheme’s expected benefits for the region. It says it has the potential to generate up to 20MW of power without the emission of greenhouse gases, resulting in a significant contribution to the UK’s obligations under the Kyoto Protocol. Additionally, it will firmly establish the south west region as a leader in the field of wave power electricity generation, create a significant number of new jobs, and lead to the creation of an industry capable of manufacturing, deploying, maintaining, inspecting, repairing and decommissioning a potentially wide range of WECs.

Juliet Williams, chairman of the SWRDA, called the government’s go-ahead for the scheme in September ‘a huge step forward for Wave Hub… a groundbreaking renewable energy project in south west England that will lead the world in the development of wave energy technology’.

SWRDA says the economic case for the Hub is compelling, and backed up by an independent economic impact assessment which it commissioned some time ago. It claims the Wave Hub could create 1800 jobs and inject UK£560M (US$1.14B) into the UK economy over 25 years. Almost 1000 jobs and UK£332M (US$678M) would be generated in south west England alone, it says.

The scheme’s environmental credentials are equally important, it says. Wave Hub could save 300,000 tonnes of carbon dioxide over 25 years.

The consent announcement was also welcomed by Maria McCaffery, chief executive of the British Wind Energy Association (BWEA), the trade and professional body for the UK wind and marine renewable industries. ‘This is a fantastic confidence boost for this emerging industry,’ she says. ‘Wave Hub will be a crucial part of the learning curve for everyone with an interest in wave energy development around the world and will underpin the growing confidence in these exciting technologies. It’s this kind of progress that makes the UK the global hotspot for the expansion of carbon free energy from the sea and we must ensure it remains so.’

Tim German, director of the Cornwall Sustainable Energy Partnership, referred to what he called the ‘UK’s green peninsula’. He said: ‘It will be a key feature of the industrial revolution of the 21st century, playing an important role in Cornwall’s economic and low carbon future.’

Covering an area of sea measuring some 4km by 2km, the Hub will see each wave device developer being granted a lease of between five and 10 years in an area of approximately 2km2. The water at the deployment site is approximately 50m deep. Up to 30 wave energy devices are expected to be deployed, and the Wave Hub is expected to be operational in 2009.

Government consent represents the last major hurdle in the development of the project from concept stage through planning. At the end of April, SWRDA approved the UK£21.5M (US$43.9M) of funding. The investment means the Wave Hub has the necessary UK£28M (US$57M) needed to build it. Later, in May, a fourth wave device developer was chosen for the project.

Australia-based Oceanlinx announced it would deploy its unique wave energy converter, which combines the established science of the Oscillating Water Column (OWC) with its own patented turbine technology. A full-scale operational unit has been successfully constructed and tested at Port Kembla in New South Wales, Australia.

The company, which was founded ten years ago, is also pursuing wave energy projects in North America, Mexico, South Africa and Hawaii, but Wave Hub will be Oceanlinx’s first installation in Europe.

Oceanlinx joins three other wave device developers that have already been selected to use Wave Hub to deploy their wave energy device on a scale not seen before in the world. They are Ocean Power Technologies Limited, Fred Olsen Limited and WestWave, a consortium of E.On and Ocean Prospect Limited, using the Pelamis technology of ocean-power-delivery. Together they hope that the Hub will put the south west England and the UK at the forefront of emerging wave energy technology by providing a leased and consented area of sea for the pre-commercial testing of wave energy devices.

Environmental effects

Last year, an independent assessment of the scheme found that it would have little effect on marine life. The Hayle estuary is internationally recognised for its biodiversity value and much of the estuary is included within a Site of Special Scientific Interest (SSSI) and an RSPB Reserve.

As Britain’s most south-westerly estuary, its inter-tidal and salt marsh habitats provide an important feeding and resting area for birds on migration. In addition, the estuary supports commercial lobster, crawfish and crab fisheries. Inland, there are large areas of species-rich dune habitats, including the Gwithian to Mexico Towans SSSI. Detailed surveys of terrestrial, inter-tidal and sub-tidal habitat, flora and fauna have been carried out as part of the Environmental Impact Assessment. Specialist surveys were also undertaken of birds and cetaceans using the area of the array at sea.

It is recognised that the wave energy array will restrict use of an area of sea by fishermen and marine traffic. But, equally, it is also recognised that there may be benefits to fisheries from the creation of a no-take zone within a spawning and nursery area used by several commercially important species and from the creation of new habitats.

The area is also popular for holiday makers, with a number of resorts and caravan parks located amongst the dunes. Significant impacts on tourism and recreation are not anticipated but the effect of the wave array on waves reaching the shore will be addressed. The issue has raised concern in the town of Newquay to the north, its Fistral Beach being internationally renowned in the surfing community.

Other issues being considered include archaeological features that may be present on land or the seabed and effect on water quality during the construction and operation and possible contamination that may be disturbed during construction. Overall, however, the many benefits of the scheme are considered to considerably outweigh the impact of any negative effects.

For further details on the Wave Hub project, please contact: Nick Harrington, Project Manager, Wave Hub, South West of England Regional Development Agency, North Quay House, Sutton Harbour, Plymouth, PL4 0RA, UK. Email: nick.harrington@southwestrda.org.uk. www.wavehub.co.uk