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Into the swim: Alstom says the turbine will be easy to install
A tidal turbine installed off the coast of Orkney has reached full nominal power of 1MW after a series of gradual increases in power since the beginning of the year.
Since its immersion in January at the European Marine Energy Centre, Alstom’s grid-connected full-scale tidal device has generated more than 10MWh of electricity, in actual operating conditions.
Both figures represent major milestones in the development of tidal-stream energy, said the company. The tidal turbine has been tested in different operational conditions, showing a reliability and performance in line with its design models, said Alstom. The next step will be to demonstrate the full range of autonomous running capabilities of the turbine, continue with the planned maintenance, and gather evidence for certification. Endurance and reliability will also be tested until 2014. Tests in pilot farms will follow before the start of full commercial production.
Rob Stevenson, vice-president of Alstom’s ocean business, said: “We are enthusiastic. The tests successfully demonstrated the advantages of the tidal turbine in the challenging environment of the Fall of Warness in Orkney.”
Alstom’s tidal turbine has a 22m-long nacelle and weighs 150 tonnes. Its rotor has three pitchable blades and a diameter of 18m.
The tidal turbine is capable of floating. Buoyancy enables the nacelle to be towed easily to and from the point of operation and attached to its pre-installed foundation. Avoiding the need for specialised vessels and divers, this feature minimises installation and maintenance costs, and reduces the time needed for installation.
The unit operates fully submerged with no part piercing the surface, in a water depth of about 40m. The nacelle can rotate around the vertical axis to face the incoming tide at an optimal angle, and so extract the maximum energy potential.