There is no shortage of speculation when it comes to what will power our vehicles in a more eco-friendly future. But the truth is that we don’t know what it will be, nobody knows, and nobody will for some time. Electric cars still suffer from many of the same drawbacks that put companies like Detroit Electric out of business in 1938, corn-based ethanol takes land away from food production, algae fuel can’t be produced efficiently, and oil is just plain going to run out. So the future of transportation is still open to anyone who can make their technology viable before everyone else does. Audi, and their new partner Joule, think they might have the answer.

What they plan on producing is a variety of what they call e-fuels, such as e-gas and e-diesel. These are made by combining hydrogen extracted from water via electrolysis with CO2 that comes from processing organic waste. This method synthesizes methane, and since the infrastructure and technology for powering cars with natural gas already exists, Audi believes that the difficult process of implementation will be much easier than it is with other alternative fuels. What’s more, the manufacturing process removes CO2 that would otherwise go into the atmosphere. Since Audi says that the actual manufacturing will use only wind and solar energy, and the fuel only gives off as much CO2 when burned as it absorbed during manufacturing, the fuel comes out carbon-neutral. Audi has even announced plans to build a car specifically for this new kind of fuel that will be based on the A3. This A3 TCNG will work like any other dual-fuel vehicle and will allow the owner to choose between e-fuel and regular gasoline.

If you have your doubts, you are not alone. The report in Inhabitat has been met with its share of skepticism, although Audi is in no way claiming that the fuel will be ready for the mass market tomorrow. But they do say it will be ready by 2020, and that’s quite a bold claim. Even if issues of cost can be addressed, it’s hard to imagine that there would be enough solar and wind-generated electricity, not to mention organic waste, around to make this a really all-encompassing solution, but we’re really going to have to wait and see.