Wave Hub Environmental Statement

Abstract

A Non-Technical Summary is also available here.

The South West of England Regional Development Agency (SWRDA) is proposing the Wave Hub project to provide the electrical infrastructure necessary to support and encourage developers of wave energy converter devices (WECs) to generate electricity from wave energy.

Wave Hub will facilitate WEC development through final demonstration and pre-commercialisation development stages by allowing developers to install, operate and monitor commercial-scale WECs in realistic offshore marine conditions over a number of years. In this respect, Wave Hub will perform the function of a WEC proving zone for the efficient delivery of power derived from renewable wave energy.

Wave Hub supports:

  • the UK government’s energy policy by contributing towards the UK’s drive to meet the challenges and achieve the goals of the new energy policy including a 60% reduction in carbon emissions by 2050; and
  • the South West region’s commitment to encouraging technologies for renewable energy generation that will contribute to the region's renewable energy target of 11% - 15% of electricity production by 2010.

Wave Hub will be based onshore at Hayle, Cornwall. The offshore elements of Wave Hub, including the WECs, will be situated in approximately situated some 10 nautical miles out to sea off St Ives Head (see Figure 1.1).

Wave Hub’s infrastructure can be divided into three main components. This infrastructure provides the:

  • Firstly, there will be offshore infrastructure comprising four underwater power converter units (PCUs; i.e. transformers and circuit breakers that receive power generated by the WECs) connected back to a termination and distribution unit (TDU) via semi-flexible connector cables placed on the seabed within a 4km x 2km deployment area. Various aids to navigation will be positioned around the deployment area. It is within the deployment area that the WECs and their associated infrastructure (e.g. anchors, moorings, cables) will be installed.
  • Secondly, there will be a 25km sub-sea cable comprising power cables and fibre-optic communications connecting the Wave Hub’s offshore infrastructure and onshore infrastructure.
  • Thirdly, there will be onshore infrastructure at Hayle comprising a new substation and other operational facilities. The new substation will provide an intermediary connection point for the cable to the 33kV bulk electricity system operated by Western Power Distribution (WPD) at the existing Hayle substation complex from where electricity generated at the Wave Hub will be passed into the regional and national electricity supply networks (e.g. the National Grid).

The WECs do not form part of the Wave Hub’s infrastructure but are material to its consideration as a project and the consent application supported by this Environmental Statement.

In essence, all WECs comprise a carcass (made of steel, concrete or composites), electrical and hydraulic equipment, electronic control and telecommunications equipment, and moorings.

All WECs will be floating or semisubmersible, connected to the Wave Hub’s PCUs by cable, and anchored to the seabed via varying numbers of mooring lines. WEC units may take a number of forms, with varying outputs, operating ranges, numbers in an array, and spacings.

The main types of WECs will be oscillating water column devices (partially submerged), buoyant moored devices (floating on or just below the surface of the sea), or hinged contour devices (floating on the surface of the sea). Figure 1.3 provides an illustration of some of the WECs that are under development.

Different developers will be able to connect either individual WECs or arrays of WECs to a PCU at any one time. All WECs and their moorings / anchors will be installed within the same 4km x 2km deployment area as used for the Wave Hub’s PCUs and TDU.

By virtue of providing four PCUs, the deployment area will accommodate four connections from a WEC or an array of WECs.

Wave Hub will have a maximum output of 20MW (i.e. 4 PCUs x 5MW). This output effectively limits the scale and/or number of WECs and WEC arrays that can be connected to the Wave Hub.

At 20MW, Wave Hub will produce the equivalent amount of energy to power approximately 7,500 average UK homes. In local terms, this translates to around 3% of Cornwall’s domestic energy requirement.