Bord Gais and Irish tidal energy partner OpenHydro were given the go-ahead to develop a 100MW tidal array off Torr Head, on the north coast of Antrim.
Meanwhile, a consortium led by Danish energy company Dong was named the successful bidder to develop a wind farm of up to 600MW capacity, off the southeast coast of County Down.
Dave Kirwan, managing director of Bord Gáis Energy, said: “This project is a milestone for the development of tidal resources on the island of Ireland and marks our ongoing commitment to renewable assets.”
The tidal project, expected to be finished by 2020, will potentially be the first of its kind in Ireland.
Dong’s contract marks its first venture in Northern Ireland. It is a 50 per cent partner, with Northern Irish renewables developer B9 and global operator RES making up the remaining share.
Benj Sykes, Dong Energy Wind UK’s country manager, said the company had also signed a lease with Belfast Harbour that would allow it to create a bespoke production facility and handle huge vessels.