Wave Hub is a grid connected test site. It aims to facilitate WEC development through final demonstration and pre-commercialisation development stages by allowing developers to install, operate, and monitor commercial-scale Wave Energy Converters (WECs) in realistic offshore marine conditions over a number of years. By doing so, Wave Hub aims to address the support gap between initial devices, typically less than 2MW, and the arrays of several devices that will be required for commercial viability. It is anticipated that the Wave Hub project will bring a variety of direct and indirect benefits to the south west region, such as:
- Production of a significant amount of clean, renewable energy in the south west region;
- Promotion of the south west region as a leader in the field of wave power electricity generation;
- Potential creation of a number of new jobs; and
- Creation of new industry and expansion of existing industry capable of manufacturing, deploying, maintaining, inspecting, repairing and decommissioning the potentially wide range of devices likely to be deployed.
The deployment area is located 16km off the north coast of Cornwall (north east of Saint Ives) and covers an area of 8km2. Within this area there are four berths for WECs and their mooring spreads. Water depths at the site range from 48 to 58m.
Each berth has its own Underwater Power Converter Unit (PCU); i.e. transformers and circuit breakers that receive power generated by the WECs via semi flexible cables. Each PCU is connected to a single Termination and Distribution Unit (TDU) which in turn connects to the onshore infrastructure via a subsea export cable.
The infrastructure present at the site allows for an export capacity of 30MW, this is upgradable to 48MW. However, the consent granted in 2007 under Section 36 of the Electricity Act 1989 allows different wave energy generation technologies to be deployed at the site with a combined capacity up to 20MW.
The 12-tonne TDU is linked to the UK’s grid network via a 25km, 1300 tonne subsea cable capable of operating at 11kV and 33kV. The cable was manufactured by JDR Cable Systems in one continuous length. It is made up of six copper cores, 48 fibre optic cores, two layers of steel wire armouring and an outer polymer sheath giving it a total diameter of 16 centimetres. As a cable protection measure, 80,000 tonnes of rock was placed over the cable along its length until 5km from the coast. This resulted in the cable being buried under approximately 0.5m of rock for most of its length. Using directional drilling the cable was buried 1-3m below the sediment surface from approximately 5km offshore.
Wave Hub’s onshore substation provides 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. Electricity generated at the Wave Hub will be passed into the regional and national electricity supply networks (e.g. the National Grid). The substation facilities include:
- Power quality room;
- Circuit breaker room;
- Metering room;
- Control room with space for WECdevelopers’ transmission equipment;
- Mess room with associated facilities for the various operators who will be monitoring; equipment or providing maintenance on an occasional basis; and
- Remotely operated vehicle (ROV) workshop and garage.
The following vessels will be required during construction and operation:
|Cable lay vessel||Installation of the subsea infrastructure.||
PDU being deployed from the vessel Nordica. Other vessels may also have been used.
A wave energy demonstration and proving site located at 50 m water depth 16 kilometers off the north coast of Cornwall in South West England.
Wave Hub was granted consent in 2007 under Section 36 of the Electricity Act 1989. This allows different wave energy generation technologies to be deployed at the site with a combined capacity up to 20MW.
Wave Hub also has a licence under Section 34 of the Coastal Protection Act 1949 (CPA) and licences under Part II of the Food and Environmental Protection Act (FEPA) 1985 for the installation of Wave Hub, its subsea cable and the stabilisation and protection of the cable by rock armouring. Developers coming to Wave Hub need to apply for their own FEPA licences. The Wave Hub Team will advise and support these applications which will be able to draw on the existing environmental and other baseline data.
- The Licence Holder must submit and agree a detailed schedule of planned construction and monitoring with the Licensing Authority at least four months prior to the commencement of any construction works. This schedule should contain timings for mobilisation of plant, delivery of materials and all installation works and timings for preparing and submitting survey specifications, data collection, analysis, report writing and dates that monitoring reports will be submitted to the Licensing Authority. Variations of the timetable and schedule must be confirmed immediately, in writing, with the Licensing Authority and include an assessment of the potential impact on the monitoring programme detailed in this licence.
- The Licence Holder must submit a Method Statement to the Licensing Authority at least four months prior to the commencement of any construction works. This Method Statement must describe the construction works in detail confirming the final choice of installation techniques, cable type and specification (including any additional shielding to mitigate potential impacts of EMF), cable burial depths, cable laying technique, contractors and vessels. Construction cannot commence until the Licensing Authority has given its written acceptance of the method statement. If the methods described differ significantly from those discussed in the Environmental Statement the Licensing Authority reserves the right to vary Licence 33383/07/0 to ensure that appropriate conditions are in place.
To ensure the integrity of the Wave Hub infrastructure and to minimise hazards to mariners the cable route should be monitored to ensure that the cable remains buried. Should the cable become exposed a separate Food and Environment Protection Act/Coast Protection Act application must be submitted to the Licensing Authority for any cable protection operation that may be needed (rock armour). In addition standard conditions of consent for miscellaneous works (permanent) apply.
An EIA was completed following a preliminary scoping study and the related Environmental Statement was submitted with all the applications. Following application an extensive period of public consultation was then undertaken which was completed in March 2007. Consents were then granted in September 2007 and the FEPA license was granted in December 2007. An additional FEPA license for cable stabilization operations was granted in August 2010. The cable and the Wave Hub were completely installed and connected to the grid in November 2010. In November 2016 Cornwall Council announced that it concluded negotiations with the Department for Business, Energy and Industrial Strategy on the transfer of Wave Hub as part of a package to put Cornwall at the heart of the emerging marine renewables sector. The Deal, agreed between the UK Government and Cornwall Council, will see the transfer of Wave Hub along with£14m of funding and the creation of a low carbon Enterprise Zone in the key ports of Hayle and Falmouth during 2017.
Wave developer Seatricity installed its second generation 162 kW device Oceanus 2 at wave hub in May 2016. After sustaining damage to one of its moorings from what was suspected to be a passing vessel, in June 2016, the device was subsequently taken to dry dock repaired and then redeployed shortly after.
There are currently no other devices deployed at the site, however Carnegie Wave Energy, Simply Blue Energy and Fortum (in collaboration with Wello) have reserved berths at the site. There are also opportunities for floating wind devices to be tested at the site.
- Direct noise and visual disturbance to birds during cable laying/removal operations, caused by the presence of machinery and increased human activity;
- Physical loss of roosting and foraging habitat along the cable trench during construction;
- Disturbance primarily through increased shipping activity;
- Loss of feeding area due to the presence of WECs;
- Impacts of accidental pollution;
- Loss or degradation of roosting and foraging habitat due to accidental pollution during construction activities.
- Increased food availability as a result of the ‘sanctuary’ created by the ATBA;
- Risk of collision / entanglement with WECs, cabling and anchoring;
- Disturbance / disorientation of birds due to lighting at night.
- Potential for an effect on marine ecology as a consequence of changes to water quality during the construction phase;
- Potential disturbance to marine communities in St Ives Bay due to the burial of the cable under the seabed;
- Potential for effect on marine habitats and species as a consequence of effects of the hydraulic and sedimentary regime of St Ives Bay;
- Potential impact on benthic communities as a result of habitat loss and disturbance due to the laying of the cable on the seabed and construction of the Wave Hub;
- Potential for habitat creation;
- Potential impact on cetaceans, elasmobranches (sharks and rays) and other marine species during the construction phase (e.g. due to water quality effects and noise) and during the operational phase due to noise generation;
- Electromagnetic field disturbance potentially affecting elasmobranchs in particular, and possibly to other marine species.
- All construction, maintenance and decommissioning works in the intertidal zone should be undertaken outside of the winter period (October to March);
- Where works during the winter cannot be avoided (for example for essential maintenance), these should not be undertaken for at least two hours after high tide where high tide Wave Hub occurs early in the morning (i.e.within two hours of sunrise);
- The duration of work and extent of work area should be kept to a minimum;
- Best working practices and adherence to the relevant Environment Agency Pollution Prevention Guidelines (PPGs) should be employed to minimise pollution risk;
- Lighting at night time should only be permitted where required for safety and navigational purposes.
- The correct specification of piles and pile driver will used for the works, avoiding the use of excessive energy (and noise generation).
- Piling activities will use a soft start procedure.
- It is proposed that the site to shore cable will be buried in the sediment by up to 3m in the near-shore waters of St Ives Bay reducing the intensity of the induced electrical field.