The mining giant's delay in the rollout of renewable energy and a fleet of electric trucks and trains in the Pilbara has raised doubts inside the company about it meeting its ambitious climate goal.

Hundreds of pages of internal BHP documents reveal how the company sold itself as a climate leader while internally finding reasons to put off action in the Pilbara.

Exclusive: Mining giant says technology is not yet advanced enough to run a fully electrified fleet but experts say it is hooked on federal fuel tax credits