Rolls-Royce has achieved a milestone in the deployment of tidal energy technology with confirmation that its prototype tidal turbine has fed over 100 megawatt hours of electrical power into the national grid.

Harnessing the reliable and predictable energy of tidal streams, the 500 kilowatt (kW) tidal turbine prototype, located subsea off the Orkney Islands in Scotland, was designed and built by Rolls-Royce wholly owned subsidiary Tidal Generation Limited.

As a reliable and predictable energy source, deep water tidal stream power generation could make a valuable contribution to meeting the electricity demands and carbon emissions reduction objectives of many industrialised nations, including the UK, Canada, Australia and the USA. It is claimed that Rolls-Royce tidal technology could generate up to 30TWh (terrawatt-hours) of UK electricity, equivalent to around 7.5% of existing UK electricity needs or enough to power 3 million homes.

Installed as part of the Deep-Gen III project, co-funded by the UK government backed Technology Strategy Board, the Rolls-Royce prototype tidal turbine is currently deployed at the European Marine Energy Centre’s (EMEC) offshore test site off the Orkney Islands. It is the first EMEC located project to both receive Renewable Obligation Certificates and to reach 100 MWh of supply to the grid.

The tidal unit’s three-bladed turbine is attached by a tripod to the seabed and can operate, fully submerged at a water depth of 40m. Its design allows the turbine to continually rotate to face the incoming tide at an optimal angle. In addition, the turbine unit is semi-buoyant and can be easily towed to and from the point of operation, minimising installation and maintenance costs by avoiding the need for specialist vessels.

Neil Morgan, Head of Energy at the Technology Strategy Board said, “This is a significant milestone for the UK marine renewables industry. The UK is well placed to exploit tidal stream energy resources and, if commercialised on a large scale, this technology could be an important part of the renewable energy mix we’ll need in the future, and could create jobs and exports for the UK.”

As part of the Energy Technologies Institute (ETI) funded ReDAPT (Reliable Data Acquisition Platform for Tidal) consortium project, Rolls-Royce is currently building a 1MW tidal turbine demonstration unit that will be deployed in mid-2012 at EMEC in Orkney. The project will deliver detailed environmental and performance information never before achieved at this scale in real sea conditions. Rolls-Royce is also working with a number of developers in advancing demonstration arrays, systematic arrangements of turbines, which will lead to large scale commercial deployment.

ETI chief executive Dr David Clarke said, “The long term viability of tidal technology depends on it becoming competitive with other renewable energy sources. Continued investment and new partners are urgently needed to maintain momentum and bring the technology to scale.”

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