The Stingray tidal generator is a tidal stream turbine developed by The Engineering Business, a Newcastle based firm. Stingray uses the flow of the tidal stream over a hydroplane to create an oscillating motion that operates hydraulic cylinders to drive a motor that, in turn, drives an electrical generator. This device is a seabed-mounted machine, to be situated typically in any water depth up to 100m. It weighs some 180 tonnes and is capable of generating 150kw. The system was tested at Yell Sound off Shetland.
Yell Sound, Shetlands, Scotland.
The programme started in 1997 with the Active Water Column Generator (AWCG), which subsequently developed into the Stingray concept. A technical and commercial feasibility study (Phase 1) in 2001 led to Phase 2 – the design, build, installation and operation of the Stingray demonstrator in Yell Sound in 2002. Phase 2 was extended into 2003 to consider various aspects of the technology in more detail.
For a commercial tidal stream development in Scotland, consents could be required under: The Electricity Act 1989 and Electricity Works (EIA) (Scotland) Regulations 2000– administered by the Energy Division of the Scottish Executive. However, this only applies to developments exceeding 1MW (s36) or involving overhead cables (s37) and does not, therefore, apply to the Yell Sound site. The Food and Environmental Protection Act 1985 - Part II - Deposits in the Sea (FEPA) – administered by Fisheries Research Services (FRS) division of the Scottish Executive Environment and Rural Affairs Department (SEERAD). Section 34 of the Coast Protection Act 1949 (a CPA consent) - s.34 of the CPA applies to areas below high water mark of ordinary spring tides (HWMOST), which are not excluded from the definitions of sea and seashore detailed in Schedule 4 to the Act.
In the case of Yell Sound, the development would not fall within the excluded area, so a CPA consent would be required. In the case of the Yell Sound site, a works licence was also required from Shetland Islands Council, which has control over development in the coastal area around Shetland and is the harbour authority for the water around Sullom Voe. Although the offshore installation of the Stingray generator does not fall within the control of the normal land-based planning system, there was the possibility of associated land-based activities during the construction phase which required planning permission from Shetland Islands Council. A seabed lease for the Stingray generator and cable route was also required from the Crown Estate.
Part of Yell Sound is a Special Area of Conservation (SAC), due to high numbers of Otters; Seal populations at Yell Sound around 2% of the total population in the UK. The low-lying peaty coastlines provide easy access to fresh water, extensive algal beds in the marine environment and large numbers of otter holts. There are Horse mussel (Modiolus modiolus) beds both within Sullom Voe and on the Mainland coast near Colla Firth. Ceteceans are regularly sited in the inner sound, especially Harbour Porpoise, Minke Whale and Killer Whale and there are a wide variety of breeding seabirds, divers and ducks including Eider.
Environmental webpage: http://www.engb.com/hse_environment.php