Direct air capture is slowly getting off the ground, with plants up and running in Iceland, Switzerland, the US, and Canada. Much of the carbon these facilities capture is either turned into a solid and stored underground or reused to manufacture various chemicals and industrial products. Now a startup called Twelve is planning to use captured CO2 to make jet fuel.

The company named their carbon conversion platform Opus. The system is modular and can be implemented in existing supply chains, taking CO2 from almost any source. The process uses electrolysis to separate the carbon and oxygen, then recombines the carbon with hydrogen to create fuel. The CO2 will be sourced from nearby ethanol plants, pulp and paper mills, and waste processing facilities.

The US Air Force tested the fuel to ensure it can be safely used without altering existing plane engines. Replacing half of a plane’s regular fuel with CO2-derived fuel can result in 90 percent fewer lifecycle emissions. Alaska Airlines has already agreed to buy fuel from Twelve.

Twelve broke ground on its factory in Washington state earlier this month. The geographic choice was due to several factors. For one, Seattle has long been a hub for aerospace innovation; SpaceX, Blue Origin, Boeing, AeroTEC, and others all have operations there. Washington also has tax incentives for sustainable aviation fuel. And two-thirds of the state’s electricity is generated by hydropower, giving it one of the highest percentages of clean energy in the country.

The facility will initially produce around 40,000 gallons of fuel a year, eventually scaling up to a million gallons a year. That’s a drop in an Olympic-sized swimming pool when taken in the context of total consumption, which reached an all-time high of 95 billion gallons in 2019.

So what are the barriers to significantly scaling up production? There’s plenty of CO2 in the atmosphere that needs capturing (more than we’d ever be able to capture and store in 100 years, as a matter of fact), and plenty of demand for jet fuel. Demand for this specific jet fuel could end up being extra-high if its price reaches parity with conventional fuel (it will be more expensive for a while), because it would allow airlines that use it to reduce their carbon footprint.

Consumers have already become more brand-conscious, when possible buying products and services from companies that mirror their values. This trend is likely to continue in the future, and conservationism will hopefully only become more and more highly valued among more people.

The biggest determinant of which airline flyers choose will likely still be price, because let’s be honest, we all like a cheap flight. But if the price for a given flight on two different airlines is comparable, consumers would feel good choosing the more planet-friendly option.

The big issue at the moment, though, is that capturing atmospheric carbon is still very costly and energy-intensive. Many direct air capture plants are built in areas that have access to cheap, abundant geothermal energy—like south-western Iceland’s Hellisheiði Power Station.

For DAC to make economic and environmental sense, the process will either have to get more energy-efficient, or energy will have to get cheaper—green energy specifically, since it wouldn’t make much sense to, say, build a coal-fired power plant to provide electricity for a facility using giant fans to filter carbon out of the air.

Despite these barriers, Twelve’s VP of project development Andrew Stevenson is optimistic. “Our goal is to de-risk the technology and the process—to operate successfully at a larger scale,” he told Forbes. “We want to scale up and build other facilities worldwide.”

Construction of the Washington plant is underway, with the facility expected to become operational in 2024.