In theory, you can make a liquid fuel from carbon in the air and hydrogen. In practice, Porsche and Siemens operate a jointly run plant in Chile (where there’s lots and lots of nice free wind energy) doing just that, to create a synthetic lab-made e-fuel. It’s theoretically carbon-neutral, and Porsche is running all of its racing cars on the stuff.
A carbon-free drop-in replacement for petrol and diesel? Sounds like utopian stuff, but it already exists. Certa is one of the big Irish fuel retailers already selling hydro-treated vegetable oil (HVO), which is a biofuel alternative to diesel. It’s supposedly 90 per cent lower in emissions than fossil diesel and it works in pretty much any D-badged vehicle. It’s around 5c per litre more expensive than diesel at the moment, but surely that’s a small enough eco-price to pay?
However, there are catches. HVO uses waste cooking oil as its main ingredient, and there are significant concerns that virgin palm oil – a big trigger of deforestation – is being illicitly mixed in with the waste oils.
“Certa was one of the first HVO suppliers in Ireland to be awarded International Sustainability Carbon Certification (ISCC) which provides full transparency and traceability throughout the supply chain,” says Laura Byrne, head of sustainable fuels at Certa. “This certification enables Certa to create and assign Proof of Sustainability (POS) certification to the businesses that it supplies with HVO.
“Global refiners are innovating rapidly, and we expect to see more diversification of feedstocks, including algae, non-food crops, and waste-based input,” Byrne says.
That diversification will prove crucial as HVO will now be competing with sustainable aviation fuel (SAF) for the same feedstocks, and global aviation’s thirst for fuel is greater even than that of motoring. Given Ireland’s position on the periphery of Europe and the fact that it’s impossible to electrify anything bigger than a Cessna, our economy will probably come to rely on SAF to a huge extent. Is it the right stuff though?
According to Professor Tom Conlon of the UCD School of Business, SAF is not yet ready for wide deployment: “In 2024 SAF accounted for 0.53 per cent of global aviation fuel requirements. In relative terms, this is still up about 100 per cent from 2023, despite the small proportions. Remember, going from concept to production on an SAF plant takes three to five years, so this is a slow burner.”
The deep pockets and good credit of our well-developed aviation financing sector might help de-risk investing in SAF. There are possibilities and potential for carbon-neutral fuels, but large investments and enormous technical resources must be brought to bear before they can make a viable contribution to reducing emissions.
