Wave Power Hub Generation Proposal for Hayle

Following a review of the potential for wave and tidal stream power in the South West of England, Halcrow Group Ltd (Halcrow) and Global Marine Systems Limited (Global Marine) have been commissioned by the South West Regional Development Agency (SWRDA) to undertake a Technical Feasibility Study for the development of a wave hub off the North Cornwall coast at Hayle.

 

Hayle, situated near St Ives on the north Cornwall coast, has been identified as a suitable potential location for the wave hub. Not only is it near an area of substantial wave activity, it also has suitable infrastructure for connection to the National Grid. Figure 2 shows the area of search within which the device arrays could be located, and an indication of cable route. Figure 3 shows where a connection to the electricity grid could be made at Hayle; the location shown is adjacent to an existing substation and former power station.

 

Indicative location of the proposed wave hub and cable

 

Indicative location of the proposed wave hub and cable for Hayle

 

Possible substation location, Hayle.

Possible substation location, Hayle

 

What is being proposed?

In order to encourage the development of wave power technology in the region, SWRDA is planning to construct a wave hub off the north Cornwall coast. This hub would provide infrastructure for several different companies to install wave energy generators. The hub would comprise an offshore connection, a cable running to shore, and a connection to the National Grid via a substation. SWRDA would also facilitate a simplified permitting process. At this stage it is anticipated that two wave device deployment zones may be required, one at 50-60m depth (16-25km offshore) and one at 25-30m depth (4-10km offshore). The devices themselves could be floating, semi-submersed or fixed to the seabed. When the project is fully operational, the area of sea occupied by the devices could be up to 10 km2, comprising a 2km2 near shore exclusion zone and an 8km2 offshore exclusion zone

 

What are the options?

Four options are being considered, each shown with a drawing indicating what they may look like:

Option 1 On-shore base with multiple cable routes extending to each developer array.

 

Option 2 Wet Hub: Underwater transformers, single buried cable to shore, secondary cables to arrays.

Hayle Wave Power Scheme - Option 2

Option 3 Purpose built floating device (vessel or buoy) containing transformers and switchgear, anchored to the seabed, single buried cable to shore, secondary cables to arrays.

Hayle Wave Power Scheme - Option 3

 

Option 4 Purpose built static device (platform) containing transformers and switchgear, fixed to the sea bed, single buried cable to shore, secondary cables to arrays.

Hayle Wave Power Scheme - Option 4

 

Note: it is also possible that a hybrid design combining two or more of the above options will best fit the project requirements.

 

These options are being assessed during the study using technical, environmental, economic, and safety criteria. The preferred option will thus be one that is technically sound and achievable, has minimum environmental impact, is cost-effective and does not present significant safety issues.

 

What are the potential benefits?

The construction of a wave hub would have a variety of direct and indirect benefits:

  • The production of a significant amount of clean, renewable energy in the South West region (potentially 30 to 40 MW);

  • Recognition of the South West region as a leader in the field of wave power electricity generation;

  • The potential creation of a number of new jobs; and

  • The creation of new industry and expansion of existing industry capable of manufacturing, deploying, maintaining, inspecting, repairing and decommissioning the potentially wide range of devices.

What are the potential environmental impacts?

The Hayle estuary is internationally recognised for its biodiversity value. As Britain’s most south-westerly estuary, its intertidal and saltmarsh habitats provide an important feeding and resting area for birds on migration. Inland, there are large areas of species rich dune habitats, including the Gwithian to Mexico Towans Site of Special Scientific Interest (SSSI). The area is also popular for holidaymakers, with a number of resorts and caravan parks located amongst the dunes.

 

Hayle’s intertidal and marine waters are of both conservation and economic importance: they are part of the St Ives Bay Special Marine Area (SMA), the estuary supports commercial lobster, crawfish and crab fisheries, and Hayle is popular for recreation. Cornwall’s coasts also support and are visited by a number of important marine species, including bottlenose dolphins, leatherback turtles and basking sharks.

 

The environmental impact assessment will involve an analysis of potential impacts on all environmental receptors.  This will include the effects of laying the cable (most of which will be offshore) and the impacts of the likely arrays of wave energy devices on marine ecology, fisheries and navigation. There will be very little terrestrial land-take, with only one cable coming ashore for most of the options.

 

What next?

The results of this public consultation will feed into both the Environmental Scoping study and the design work. The Technical Feasibility Study (including Environmental Scoping report) will be completed by the end of 2004. A decision will be taken to proceed based on all the development work (including the Technical Feasibility Study, the Project Vehicle Study and the Legal and Permitting Study) in 2005 when financing has been sourced.

 

Subject to gaining the necessary approvals and funding, it is anticipated that construction could begin in summer 2006, with the first power generated by the end of 2006.

 

We would be interested to receive your comments on the proposed wave hub development, and would be happy to answer any queries. Please address any correspondence to Peter Stothert, the Wave Hub Technical Feasibility Study Project Manager at:

 

SW Wave Hub TFS

Halcrow Group Ltd

Ambassador House

Ambassador Drive

Exeter Business Park

Exeter

Devon

EX1 3QN

 

Or email to: stothertp@halcrow.com