The world's first turbine capable of generating commercial amounts of energy was due to be installed in the seabed off Co Down today.
The £12m, 300-tonne SeaGen tidal generating machine was due to be transferred from Harland and Wolff's shipyard in Belfast to be embedded in Strangford Lough - one of the world's fastest flowing currents.
The installation operation, which includes pinning the turbine to the seabed, is expected to take two weeks.
And a subsequent 12-week commissioning phase will see scientists from Royal Haskoning, Queen's University and St Andrew's Sea Mammal Research Unit monitor SeaGen's operation and its interaction with marine life.
Bad weather prevented the 122ft-long device being installed on Easter Monday.
The crane barge being used to transport the turbine from Belfast had been stranded in Norway because of the adverse conditons.
The contraption will work like an underwater windmill but will move more slowly through the currents of the lough.
Bristol-based Marine Current Turbines, the company behind the project, said it expects to be powering more than 1,000 homes with electricity by the summer.
The project is an integral part of the Government's attempts to produce " greener" energy. Indeed, the SeaGen turbine will generate one of the most environmentally friendly forms of energy - it makes no noise, is almost completely below the the surface of the water, never runs out and has zero emissions.
The Department of Enterprise, Trade and Investment (Deti) wants to ensure 12% of electricity is generated through renewable sources by 2012, compared to the current 3%.