Aer Lingus and British Airways have agreed a multi-year deal with renewable fuels company Aemetis to supply sustainable aviation fuel (SAF) to help power the airlines' flights from San Francisco Airport from 2025.
IAG, the parent company of both Aer Lingus and British Airways, will purchase a total of 78,400 tons of SAF over seven years.
It said this is enough to reduce CO2 emissions by up to 248,000 tons - the equivalent of taking over 16,000 cars off the road - over the seven year period.
The SAF will be produced at the Aemetis Carbon Zero plant currently under development in Riverbank, California.
This plant will be powered by 100% renewable electricity and is designed to sequester CO2 from the production process, significantly reducing the carbon intensity of the fuel.
Jonathon Counsell, Head of Sustainability at IAG, said that SAF is key to decarbonising aviation and IAG has to date committed $865m in SAF purchases and investments.
"We see great potential to develop a long-term partnership with Aemetis who is at the cutting edge of producing low carbon biofuels from sustainable wastes," he added.
Eric McAfee, Chairman and CEO of Aemetis, said that sustainable aviation fuel continues to be shown to be a great solution to decarbonise aviation and can be used in existing aircraft engines.
"IAG is continuing to take a leadership position by the conversion of their fuel supply to the use of sustainable fuels. Our production of SAF in California is supported by the California Low Carbon Fuel Standard, creating new investment and jobs in disadvantaged minority communities in the state," he added.