Australian researchers have developed a way to convert existing diesel engines to burn hydrogen, potentially cutting their carbon emissions by more than 85 per cent.
And engineers say the technology, once refined, could be used to convert diesel truck engines, making an "immediate and significant impact" on Australia's emissions.
A team at the University of NSW's School of Mechanical and Manufacturing Engineering developed the technology over 18 months and created a prototype Hydrogen-Diesel Direct Injection Dual-Fuel System.
When retrofitted to a diesel engine, the technology allows it to use 90 per cent hydrogen fuel.
In tests, this cut emissions by 85.9 per cent compared to a diesel engine.
UNSW Professor Shawn Kook said the technology was now ready to use in power equipment and could be used to upgrade diesel vehicles in future.
"The first application we're hoping to establish is in mining sites where they have diesel-powered generators, meaning they're creating a lot of CO2," he said.
"We can retrofit them, we can convert them into clean-burning hydrogen energy.
"Once the technology is matured and any problems have been identified, we can expand it into trucks and towards individual buyers."
Prof Kook said researchers hoped the development would cut years off the transition to cleaner machines for mines and long-haul freight.
"Being able to retrofit diesel engines that are already out there is much quicker than waiting for the development of completely new fuel cell systems that might not be commercially available at a larger scale for at least a decade," he said.
The technology, he said, was ready to deploy on mining sites now, though its use in vehicles would require better "hydrogen storage systems".
The development, outlined in an International Journal of Hydrogen Energy paper and co-created by Dr Shaun Chan and Professor Evatt Hawkes, worked by adding hydrogen fuel directly into the cylinder of a diesel engine.
The hybrid engine also proved 26 per cent more efficient, and did not require high-purity hydrogen as needed in fuel-cell systems.
Boosting and replacing traditional diesel engines using green hydrogen technology has become a key focus of research in Australia.
Other proponents include Adelaide-based Hydrogen Direct Injection (HYDI) that demonstrated its technology on garbage trucks.
Miner Fortescue also signed a deal with Liebherr in June for 120 hydrogen and battery trucks to replace its diesel fleet.
