In a good sign for tidal power development, Alstom had plunged deep into the game. The French power and transport giant’s purchase of U.K. turbine maker Tidal Generation from Rolls Royce went through in late January, with the deal sealed when a 1-megawatt turbine built by Tidal Generation was installed at the European Marine Energy Centre.
Tidal power – like wave – is a fascinating technology to keep an eye on these days because so many new ways of extracting energy from the sea are being floated (or submerged). Companies, institutes, dreamers and schemers are offering up a panoply of visions, trying to find a way to make tidal power competitive, and many governments, especially in Europe, are encouraging the exploration.
There are designs that use vertical-axis turbines, oscillating hydrofoils, the venturi effect, tidal kites … even one based on the Archimedes Screw, according to the EMEC.
The Tidal Generation/Alstom device, tested previously at a 500-kilowatt scale, is a horizontal-axis turbine, looking a lot like the big wind turbines (something Alstom knows) that are churning out power around the world. With a rotor diameter of 18 meters, it was installed on a tripod structure at a depth of 40 meters at the EMEC tidal test site in Orkney, Scotland. The three blades on the turbine are pitchable (that is, the blades can be turned to change the rotation speed), and the turbine can rotate to face the incoming tide.
This is in the same category of device type that Verdant Power is licensed to install in the East River in New York City.
The plan is to test the 1-MW turbine “in different operational conditions off Orkney over an 18 month period,” Alstom said. “Detailed environmental information and real life sea performance data will be generated in order to further improve tidal power technology and to reach a commercial scale. The next step is to install pilot arrays prior to full commercial production.”
Alstom is already in wave energy, having taken a 40 percent stake in in the Scottish company AWS Ocean Energy. Alstom also says it is working with SSE Renewables on “creating a joint venture to co-develop the world’s largest wave farm off the coast of Orkney.”