THE RACE to develop successful tidal and wave energy systems has taken a new tack, with plans by a group involving Queen’s University Belfast (QUB) to design a fully submerged turbine that can be deployed in deepwater sites.
Bristol company Marine Current Turbines (MCT), which has been running a tidal energy project in Strangford Lough, Co Down, has secured funding with project partners, including QUB, to develop the system.
MCT technical director Peter Fraenkel told The Irish Times that the plan involved building a large model, about five to 10 metres wide, which will be tested in Strangford Lough with QUB researchers.
“We believe this will be the only submerged tidal turbine system capable of being raised to the surface without the need for any special lifting vessel,” Mr Fraenkel said.
Tidal energy operates on the same principle as hydroelectricity or “underwater windmills”, in using tidal power to drive turbines that generate power. However, suitable sites are limited, and systems are subject to damage in harsh environments. Submerged systems could open up new coastal and ocean areas with large tidal ranges or significant wave environments, the company believes.
“The unit will be fully autonomous – and surfaceable simply be sending it a suitable electronic command,” Mr Fraenkel said.
“We believe we can develop it quickly as it will use the same power units, rotors and control system as have already been tried and tested with SeaGen at Strangford Narrows.”
Mr Fraenkel added that the submerged turbine would not replace the existing SeaGen project, but could “supplement it and give a broader capability”.
Funding of £250,000 (€299,000) has been awarded for the research, and approved by British energy minister Charles Hendry who visited Strangford Lough recently to view the SeaGen system.
The funding is part of a £7 million package awarded by the British government to nine wave and tidal stream research and development projects.
“Wave and tidal stream technologies, such as SeaGen, have the potential to supply millions of homes with low carbon energy – reducing our dependency on foreign energy imports and cutting dangerous greenhouse gas emissions,” Mr Hendry said.
MCT says the first full-size submerged unit will be rated at 2 megawatts and is likely to be tested in the Minas Straits in Nova Scotia, Canada.
MCT’s SeaGen, rated at 1.2 megawatts, was deployed in Strangford Lough in April 2008.
The company says it has the capacity to generate electricity for the equivalent of about 1,500 homes and has the equivalent in energy output of a 2.5 megawatt onshore wind turbine.
It also has projects off Anglesey, north Wales, Canada’s Bay of Fundy and off the most southernly tip of the Orkney islands off the northeast coast of Scotland.
