Atlantis' flagship MeyGen project has met all the conditions required for the company start, drawing down finance through the UK's Renewable Energy Investment Fund.
It is expected to start drawing down on the grant money shortly, as it begins ramping up production.
The 400 megawatt tidal energy plant could ultimately comprise 269 turbines, installed on the seabed at Ness of Quoys in Caithness, northeast Scotland.
It should be sufficient to generate power for 175,000 homes.
In August, Atlantis raised around $US83 million towards the tidal project's construction, to be used to finance the installation of four 1.5MW turbines in Scotland's Pentland Firth - a small portion (6MW) of the 86MW planned for the project's initial demonstration phase.
Construction is expected to begin soon with ABB - the project's major design and construction contractors - due to start building infrastructure for connection to the electricity transmission grid for power export.
Atlantis expects the first supply of tidal power to be delivered to the UK national grid in 2016, and hopes to scale up to 60 turbines installed and delivering power by 2020, completing phase one.
There is no fixed timeframe for phase two, which could see the energy project increase to an industrial-scale power plant generating 400MW.
MeyGen is the first project in the world to secure leasing, environmental permitting, technology supply, power purchase and financial close agreements.
MeyGen is due to become the world's largest tidal stream turbine power plant.
The world's largest tidal power plant is at Lance, France, and is capable of generating 240MW of electricity, less than one-fifth of the Incheon plant's projected capacity.
Atlantis is also working on tidal energy projects off the coast of Canada.
Last month Atlantis announced that its Canadian subsidiary had been awarded a Feed-in Tariff for up to 4.5MW of tidal generation to be deployed at the Fundy Ocean Research Center for Energy (FORCE) in Nova Scotia.
The company's genesis was in Australia, where it undertook scaled testing in 2002.
It later became one of the first companies in the world to successfully connect a tidal current turbine to the grid, at a dedicated test facility in Victoria.
The company relocated to the UK in 2009 and in 2010 started work on the MeyGen project.
Atlantis' tidal wave system is of a very different design to Perth-based Carnegie Wave Energy, which is testing its CETO units off the coast of Western Australia.
The world's largest tidal power plant is planned for Incheon in South Korea.
The $US3.4 billion Incheon has a nameplate capacity of 1300MW and but has stalled in recent years.
