The 2.5 billion pound ($3.28 billion) initiative, which is expected to have a capacity of up to 560 megawatts, is poised to become the world's largest floating offshore wind farm supported by government incentives, they said.
It will be located 80 kilometres (50 miles) off the coast of northeast Scotland.
"Green Volt will stimulate investment in new port infrastructure and aggregate the efforts of an advanced supply chain, helping accelerate the development of more floating wind farms," Vaargroenn Chief Executive Stephen Bull said in a statement.
The British government announced it would support a total of 131 wind, solar and tidal projects capable of generating almost 10 gigawatts of capacity, which would be enough to power around 11 million homes.
Through the auctions, held annually, the government invites renewable project developers to bid for government-backed price guarantees for the electricity produced, called Contracts for Difference.
When wholesale electricity prices are lower than the minimum, the government covers the difference. If they go above, producers pay back the difference to the government.
Once operational, Green Volt will supply clean power to the British grid, while also supplying renewable electricity to nearby oil and gas platforms.
Eni's renewable energy unit Plenitude owns 65% of Vaargroenn with HitecVision holding the rest.
