The power of the sea is to be harnessed to generate electricity at the mouth of Strangford Lough in County Down.
Strangford Lough where the turbine will be installed
Electricity for about 800 homes will be provided by a turbine to be built as part of a five-year pilot project.
The turbine, powered by the currents at Strangford Narrows, will be connected to the national grid next autumn.
Energy Minister Angela Smith said the scheme, which has been given a £4.5m government grant, would "minimise the impacts of energy generation".
Bristol-based company Marine Current Turbines has been licensed to install the single steel tower-like "monopile" which will support two 16-metre rotor blades placed three metres below the sea surface.
An electricity cable will run from the turbine to a land-based sub-station via a directionally drilled hole.
Environment Minister Angela Smith welcomed the project
Ms Smith said the initiative provided "a unique opportunity to investigate the potential to generate significant amounts of clean, renewable electricity".
"Tidal turbine technology is one of the key renewable technologies that will help the UK achieve the carbon dioxide emission reduction targets and is a clean, sustainable replacement for ever more expensive fossil fuels," she said.
"This project fits closely with government's commitment to take action now to support the development and use of renewable forms of energy."
Martin Wright, managing director of Marine Current Turbines, said Strangford Lough had one of the strongest tidal currents in the British Isles and was therefore "a perfect location for us to test a pre-commercial device".
However, environmental watchdog, the Joint Marine Partnership, said any "negative impact" caused by the project on the lough's wildlife would "be unacceptable".
Spokesperson Kate Hutchinson described the Narrows as "a highly sensitive environment" which supported "internationally-important wildlife".
"As this is a new technology, we do not know its full environmental impacts, for example on large marine animals like seals and cetaceans, and seabed species and habitats located downstream of the proposal in the lough," she said.
"In principle, the Joint Marine Partnership strongly supports the development of marine renewable technologies, to combat the effects of climate change, but these must be sited appropriately."