The Northern Goldfields solar project will include a 27.4MW solar farm at Mt Keith and a 10.7MW solar farm and 10.1MW battery at Leinster to displace power currently supplied by diesel and gas turbine generation.

BHP estimates the project will reduce emissions from electricity use at Mt Keith and Leinster by 12%, based on FY2020 levels.

It will result in an estimated reduction of 540,000 tonnes of CO2e over the first 10 years of operation - the equivalent of removing up to 23,000 combustion engine cars from the road every year.

"This is the first large-scale onsite solar farm and battery that BHP has commissioned at any of its global operations," BHP Nickel West asset president Eddy Haegel said.

"The Northern Goldfields solar project will further improve our position as one of the lowest carbon nickel miners in the world.

"This announcement follows the nickel supply agreement we signed with Tesla last week. Sustainable low carbon nickel is essential for our battery and electric vehicle customers."

The solar farms and battery will be built, owned, and operated by TransAlta as part of the power purchase agreement extension signed in October 2020.

Construction will begin in the December quarter and is expected to take 12-14 months, subject to WA government approvals.