Shetland is bidding to become Scotland's renewable energy powerhouse with plans to build one of the world's largest community wind farms.
The council hopes to see a major harnessing of wind power
Scottish and Southern Energy (SSE) signed a partnership agreement with Shetland Islands Council on Friday.
The project, which depends on planning permission and a seabed cable, would see the building of a 200-turbine farm.
It would produce about 600 megawatts, which SSE said would be enough to power a quarter of all Scotland's homes.
Developers also estimated the project could generate about £20m a year for the community.
The agreement between Viking Energy, the company established to represent the council's interests in wind farm development, and SSE was signed at the island's Busta House Hotel.
It was at the same venue nearly 20 years ago that another agreement was reached with the oil industry securing Shetland's economic future.
Under the agreement, the new partnership will later this year, submit a planning application for the wind farm.
Its development is subject to, amongst other things, planning consent being secured and to the construction of a sub-sea cable between Shetland and the mainland of Scotland.
Chairman Sir Robert Smith, who signed the partnership agreement for SSE in Shetland, said: "SSE has a long-established track record in renewable energy and ambitious plans for the future.
"This agreement helps pave the way for a renewable energy project which can be a world leader in terms of scale, the richness of the natural resources being harnessed and the involvement of the local community.
"Our partnership with Viking Energy is an exciting and significant step forward and I am optimistic that our joint venture for this leading-edge renewable energy project will become a reality."
Scottish Greens MSP for the Highlands & Islands, Eleanor Scott, said Shetland Islands Council should be congratulated.
She said: "As well as contributing to the battle against climate change, community-owned wind farms help ensure that profits and benefits stay in the locality. I look forward to seeing the proposals in more detail."