OEMs throw weight behind tidal energy development

The engineering prowess of two large OEMs has been making inroads to harnessing the power of the oceans and seas for renewable energy generation. Two heavyweights of the industrial world, Rolls Royce and Siemens, have both stepped up developments and are yielding positive results.

Rolls Royce says it has reached a 'milestone' with its pioneering tidal technology as it supplies 100MWh to the Scottish Grid. The underwater 500kW tidal turbine was designed and built by Rolls Royce wholly owned subsidiary Tidal Generation. The prototype turbine is located off the Orkney Islands and takes advantage of the reliable and predictable tidal streams naturally generated there. Robert Stevenson, vice president of Power Ventures at Rolls Royce, said: "Rolls Royce has injected its world class engineering expertise and incubation processes to deliver this innovative renewable energy project. Reaching the 100MWh milestone highlights the significant potential of cleaner, greener tidal power as part of a diversified UK energy mix. Having proven the capability of tidal energy, Rolls Royce is well placed to meet any future demand with larger, more efficient technology on a commercial scale." The tidal unit's three-bladed turbine is attached by a tripod to the seabed and can operate fully submerged at water depth of 40m. Its innovative 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. Additionally, Siemens is also keen to strengthen its activities in underwater renewable technology by increasing its stake in UK based Marine Current Turbines (MCT) to 45%. MCT uses a similar conceptual technology to that of Rolls Royce in that the turbine is on a horizontal axis. The company has also successfully implemented its first commercial scale demonstrator called SeaGen in Strangford Lough in Northern Island. The technology is effectively similar to a wind turbine, with the rotor blades driven by tidal currents. Michael Axmann, chief financial officer of the solar and hydro division within Siemens' Energy Sector, said: "With this increase in its stake, Siemens is strengthening its activities in ocean power generation. We will actively shape the commercialisation process of innovative marine current power plants."