The multi-gigawatt-scale electrolyser factory being built on a 100-hectare site in Gladstone was a 50-50 joint venture between FFI and Plug Power Inc.
"The facility in Gladstone is going ahead as planned - nothing changes," FFI CEO Mark Hutchinson told an investor briefing on Friday.
"We want to control our own destiny."
Dr Hutchinson said the global need for electrolysers in the next few years would be huge.
Plug would still supply electrolysers for some of FFI's projects, he said.
"The feeling really was that we were advanced on our own technology - the IP was ours. We can do it at scale," he said.
"It will be Australian technology and we're going to do that on time."
Fortescue executive chair Andrew Forrest said Dr Hutchinson has been appointed chair of Fortescue's green technology, battery and vehicle control systems company WAE Technologies.
He will remain FFI CEO.
Dr Forrest said recent meetings in Europe had provided confidence five FFI green energy projects would reach final investment decisions in calendar 2023, allowing first production in 2024.
Batteries are also fundamental to the rapidly growing global hydrogen fuel cell industry, making it a focus for Fortescue, he said.
The plan to step beyond fossil fuels is on schedule, Fortescue said in a statement to the ASX.
Civil works have begun on the installation of solar as part of the $US700 million ($A985 million) Pilbara Energy Connect project to decarbonise remote sites in the region.
Battery electric haul trucks, ammonia locomotives and hydrogen-based transport and refuelling will be tested on-site in the next quarter.
The first prototype green ammonia locomotive has been delivered to Port Hedland for testing before it is deployed in Fortescue's rail operations.
Last month's opening of Western Australia's first green hydrogen refuelling station in partnership with ATCO Australia will enable Fortescue, ATCO and others - including WA Police - to run hydrogen fuel cell vehicles.
A successful proposal has been submitted to develop a precinct at the Boodarie Strategic Industrial Area in Port Hedland and the Ashburton North Strategic Industrial Area near Onslow for potential green ammonia and green iron production.
Fortescue is also working with Primetals Technologies and Voestalpine to evaluate a new green ironmaking process using hydrogen and Pilbara ores.
There was no change to FY23 guidance for the Fortescue group.