To be sure, e-fuel won’t be coursing through nozzles at public stations anytime soon. Refiners have a lot of work to do in perfecting high-volume methods to produce e-fuel in enough quantity and at a comparable cost to gasoline. And there are other issues, too.
For example, producing e-fuel requires a lot of water, which is a scarce commodity in many parts of the world. It also requires electricity from renewable sources.
Bentley CEO Adrian Hallmark told Britain’s Autocar magazine that progress developing e-fuels is exciting, but that it won’t change the brand’s plans to replace internal combustion engines.
“There’s no road map for industrialization at the scale that would be needed for e-fuels to replace fossil fuels,” Hallmark said. “The tech is there, and you could mix regular fuels with e-fuels to reduce CO2, but our view is there would be no chance in the foreseeable future to reach net zero within an acceptable time scale.”
Porsche, on the other hand, invested $75 million in a company that produces e-fuels in Chile.
But one of the biggest obstacles — the compatibility of e-fuels with fossil fuels — appears to already be in automakers’ rearview mirrors. Automakers say e-fuel is a direct, drop-in replacement for gasoline. It does not require automakers to modify engines, fuel system components or emissions systems, a notion that Greg Davis, a mechanical engineering professor at one of the nation’s largest schools for auto engineers, Kettering University, agrees with. Davis has studied alternatives to gasoline, including hydrogen and e-fuel.
“It can be a drop-in replacement that would require very few changes, maybe just a bit of a calibration change,” Davis told Automotive News. “I don’t anticipate any changes to the emissions system or the catalytic converter.”
That’s massively important as the transition to EVs swallows up the majority of product development funds for traditional powertrains.
Speakers at the SAE International panel in Detroit agreed that an internal combustion vehicle running e-fuel could be nearly as clean as a battery-electric vehicle.
But that doesn’t mean pure air — with no CO2, nitrogen oxides and other greenhouse gases — comes out of the exhaust pipes of vehicles burning e-fuel. Far from it, and this where things get complicated. E-fuel is intended to be a carbon neutral fuel, meaning that the CO2 it produces must equal the CO2 required to make and transport it.
To do that, the electricity required to separate hydrogen from water must come from a renewable source, such as a wind turbine, solar panel or a hydroelectric dam.
Using e-fuel in a gasoline or diesel car requires about five times more renewable electricity than running a battery-electric vehicle, according to a 2021 paper in the Nature Climate Change journal, Reuters reported.