Siemens is now backing SeaGen, the first commercial tidal system, deployed at Strangford Lough in Northern Ireland.

BBC: Tidal power gets a stormy birth off coast of Scotland

The SeaGen project in Northern Ireland is the largest grid connected tidal turbine in the world.

BBC: UK tidal power has huge potential, say scientists

"In general, the results were very good, the flicker levels were quite low, " said Joseph MacEnri from ESB International who assessed SeaGen.

BBC: UK tidal power has huge potential, say scientists