The US-based group controlled by billionaire Warren Buffett is planning what it said could be Canada’s biggest wind farm after successfully tying up a corporate power deal for a smaller project that will run without government subsidies.

BHE Canada, a subsidiary of Buffett’s Berkshire Hathaway Energy, is looking for offtakers for long-term power purchase agreements (PPAs) for the Forty Mile Wind Farm it is backing in southeast Alberta.

This already-permitted project – under development by global renewables group RES – “will have a generation capacity of 398.5MW, potentially making it the largest wind power project in Canada,” said BHE in a statement.

At that scale, Forty Mile would outstrip the 300MW Henvey Inlet project completed this week as the largest ‘single-phase’ wind power project in Canada.

The announcement on Forty Mile came as BHE Canada said it has tied up a PPA with a “large Canadian corporate partner” for most of the output from the 118MW Rattlesnake Ridge – also in Alberta and developed by RES – which the US group is privately financing through equity and debt.

Rattlesnake Ridge will cost more than $200m to develop and is expected to start generating in 2021, said Berkshire Hathaway, which is a major player in the US renewables market.

Canadian wind energy association CanWEA said the Rattlesnake Ridge deal “ represents the largest wind energy procurement by a non-utility customer in Canada”.

Recharge reported earlier this year how Alberta’s power market structure, and combination of strong wind resources and retiring fossil generation, made it promising ground for corporate deals.

CanWEA president Robert Hornung said: “Alberta’s unique combination of wind resource, open market structure and emerging climate policy make it possible to secure low-cost power for the Alberta grid.

“That in turn provides an incredible opportunity for significant investments in the wind energy industry while also presenting Albertans with diverse economic opportunities.”

Subsidy-free solar made its Canadian debut in Alberta earlier this year when Germany’s Innogy said it would go ahead with 57MW of projects.