Fortescue posted a 23 per cent increase in bottom-line net profit to $US1.9 billion ($A2.7 billion), on revenue of $US8.4 billion ($A11.9 billion).
The group, chaired by billionaire and green energy fan Andrew 'Twiggy' Forrest, delivered record shipments of 100.2 million tonnes in the half year ended December.
"It's been a standout first half of the financial year," Metals and Operations CEO Dino Otranto said.
"We have the lowest operating cost in the industry, and decarbonisation is pushing that even lower."
Fortescue is eliminating the use of diesel fuel across its Western Australia-based Pilbara fields.
"The more diesel we eliminate, the less exposure we have to price volatility, and the stronger and more predictable our margins become," Mr Otranto said.
Fortescue has installed thousands of solar panels at its flagship Cloudbreak iron ore mine and construction is underway on its first wind farm.
"We've delivered two large battery energy-storage systems at our sites and we're working with leading global manufacturers to roll out electric-mining equipment, battery systems and large-scale renewable infrastructure," Mr Otranto said.
"A few years ago, this would have seemed ambitious.
"Today it's part of how we operate and it's lowering our cost base as we build it."
Fortescue's underlying first half earnings - before interest, tax, depreciation and amortisation - rose by 23 per cent to $US4.5 billion ($A6.4 billion).
Fortescue expects to ship 195-205 million tonnes of iron ore in 2025/26.
It declared a first-half dividend of 62 cents per share, up 24 per cent from 50 cents in the prior corresponding period.
