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U.K. issues terms for study of 8,640-mw Severn tidal  

The United Kingdom plans to perform a feasibility study of the Severn Barrage tidal power project, which could have a capacity as high as 8,640 mw.

This project on Severn Estuary between England and Wales will use conventional hydroelectric equipment to generate an estimated 17 terawatt-hours per year, supplying 5 percent of the U.K.’s electricity from renewable sources.

The Department for Business, Enterprise, and Regulatory Reform says the two-year study will be performed by a cross-government team also involving the Welsh Assembly Government and the South West Regional Development Agency. The study team is to report to the secretary of state for business, supported by ministers from various agencies.

The feasibility study is to consider all tidal range technologies, but not tidal stream technologies. Tidal range is the vertical difference between the highest high tide and the lowest low tide — up to 14 meters in the Severn Estuary. There are two main tidal range technologies: barrages that capture the high tide for release through hydropower turbines; and lagoons, artificial impoundments constructed in shallow water areas.

The study is to: assess in broad terms the costs, benefits, and effects of a tidal project in Severn Estuary; identify a single preferred project from a number of options; consider measures needed to advance the project; and decide whether the government could support such a project and on what terms.

The U.K.’s Sustainable Development Commission (SDC) issued a report in October 2007 backing development of Severn Barrage, but urged that the government own the project to protect environmental and social interests. SDC estimated the project would cost about 15 billion pounds (US$30 billion).

Ireland launches ocean development program

The government of Ireland has established a 26 million euro (US$38 million) program for activity, grants, and support over three years to develop ocean energy in Ireland. In addition, the government announced the first guaranteed price for wave energy and the establishment of a wave energy test site.

In 2008, this initiative includes:

According to a recent report on renewable energy in Ireland, it is feasible to generate 42 percent of the country’s electricity from renewable sources by 2020, up from the current target of 33 percent.

Consortium advances wave and tidal research

The Supergen Marine Energy Consortium in the United Kingdom has begun the second phase of its research on wave and tidal energy converters. The ultimate goal of this work is to increase knowledge and understanding of the interactions of these converters, from model scale in the laboratory to full size in the open sea, says Gareth Harrison with the University of Edinburgh, which is a member of the consortium.

This phase of the research program began in October 2007 and is scheduled to be completed in September 2011. The scope and research priorities have evolved in response to recent developments in the marine energy industry, such as deployment of prototype units, research and development road-mapping work by the U.K.’s Energy Research Centre, and outcomes from the consortium’s work in the first phase of the program.

In this phase, researchers will focus on: arrays of energy converters, radical design approaches, robust design support, reliability of marine energy systems, and economic challenges posed by the variable nature of the marine resource.

The consortium recently received £7.8 million (US$15.5 million) in funding from the U.K.’s Engineering and Physical Sciences Research Council to support this work.

The Supergen Marine Energy Consortium includes the universities of Edinburgh, Heriot-Watt, Strathclyde, Lancaster, and Queens Belfast, as well as other academic and industry collaborators. Professor Robin Wallace from the University of Edinburgh leads the consortium.

The first phase of the consortium’s work was intended to increase understanding of the extraction of energy from the ocean, to reduce risk and uncertainty for stakeholders in developing and deploying the technology, and to encourage the inclusion of marine energy in future energy portfolios.

— For more information on the consortium, visit the Internet: www. supergen-marine.org.uk.

Wave technology being tested in Ireland

Wavebob Ltd. is producing electricity using its Wavebob technology. The 250-kw device is deployed at the Marine Institute/Sustainable Energy Ireland’s wave energy test site in the Atlantic Ocean off the coast of Ireland.

Wavebob is a buoy structure that contains three or four motor-alternator sets. The device consists of a float structure that rests on the water surface and a second unit below the surface of the water. The two pieces are linked by a shaft, and the up and down motion of the waves drives a piston that produces electricity. This technology is referred to as a single-point absorber. The natural frequency of the Wavebob device may be set to match the height of a typical ocean swell to ensure the unit can ride large waves and produce electricity.

The unit deployed off Ireland is a quarter-scale device. The entire structure is 8 meters high and has a diameter of 20 meters. When scaled up to full size, each Wavebob device will have a capacity of more than 1 mw, says Andrew Parish, Wavebob chief executive officer.

Briefly …

Tidal power developer Marine Current Turbines and npower renewables, both of the United Kingdom, are jointly developing the 10.5-mw Skerries tidal stream power project off the coast of Anglesey, North Wales. The project is to consist of seven 1.5-mw SeaGen turbines. … Wave energy developer Renewable Energy Holdings plc (REH) achieved initial operation of its first CETO II wave energy prototype at the CETO test site off Fremantle, Western Australia State. The unit was deployed January 31, and subsequent units are to be deployed at the test site in coming months.


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