Iron ore giant Fortescue estimates the electric train engines will help reduce the company's diesel use by about one million litres annually as it strives to eliminate fossil fuels from its operations by 2030.
"This train is part of a much, much bigger program of a complete decarbonisation of all of our assets, generation, distribution, and all of the equipment they have on a mine site," Fortescue Metals and Operations chief executive Dino Otranto told AAP on Thursday.
Mr Otranto was upbeat about the pace change that is under way at Fortescue, saying the 2030 target could be meet sooner.
"Watch this space," he said.
"We might even come in a little bit earlier ... we're really encouraged by some of the equipment coming on a little bit earlier than we planned."
The locomotives' batteries have a capacity of 14.5MWh, the equivalent of 200 to 300 passenger electric vehicles, Mr Otranto said.
They will eventually replace the miner's fleet of about 70 diesel locomotives, and will be powered by renewable energy delivered via Fortescue's Pilbara Energy Connect program.
"For a mining operation of this scale, decarbonisation only works if renewable energy is firm, reliable and available 24/7," Mr Otranto said.
"That's why we're building an integrated system combining large-scale solar and wind generation, battery storage and transmission infrastructure."
The plan includes more than 480km of already constructed high-voltage transmission lines to link Fortescue's energy infrastructure to its operations and rail network.
"This infrastructure enables renewable power to replace diesel and gas, in real time, across the Pilbara," Mr Otranto said.
Power for the network will be generated in part by a 100 megawatt solar farm at Fortescue's North Star Junction site, where a 250MWh battery energy storage system has recently been installed.
The miner has almost finished building a 190 megawatt solar farm at its Cloudbreak operation and has plans to construct two more, potentially boosting energy generation by more than a gigawatt.
Fortescue said its growing portfolio of solar, wind, battery storage and electrified transmission infrastructure will help it reach its 2030 Real Zero Target.
Mr Otranto said the challenges the company was facing as it chased down the target were not implementing the technology or the engineering behind it, but working out how to maintain its production levels using renewable energy.
"Real Zero is about transforming the way we power our assets, move our materials and run our operations, not offsetting emissions but eliminating them," he said.
Fortescue shipped 100.2 million tonnes of iron ore in the December quarter, three per cent higher than the equivalent half in 2024 and its highest ever output for a first half.
Higher-than-expected production costs resulted in a marginally weaker quarter.
AAP's reporter travelled to Port Hedland as a guest of Fortescue.
