Can Sustainable Aviation Fuel Be as Cheap as Fossil Fuels?

Not without a big honking subsidy from Bill Gates.

United Airlines wants to buy a lot of SAF
United Airlines wants to buy a lot of SAF.

Brooks Kraft/ Getty Images

Sustainable Aviation Fuel (SAF) is filling that holy grail that will keep airplanes up in the air without carbon emissions. One of the companies trying to make the stuff in quantity is LanzaJet, funded in part by Bill Gates' Breakthrough Energy. It's opening a plant in Georgia in 2023 that will double the United States' SAF capacity. Breakthrough is ponying up a $50-million grant to subsidize the cost and bring it to price parity with fossil jet fuel.

Akshat Rathi of Bloomberg explains that the process of making SAF is energy intensive. "That means, without subsidies or other incentives, the cost of LanzaJet’s SAF from the first plant would be about twice as expensive as its fossil-fuel cousin at current prices. To allow LanzaJet’s SAF to compete in the market, the company sought 'concessionary capital'—money that comes in the form of grants or low-interest loans."

Lanzajet Process
How it works.


LanzaJet makes alcohol-to-jet (ATJ) technology to convert ethanol into Synthetic Paraffinic Kerosene (SPK) or Synthetic Paraffinic Diesel (SPD) through "four primary process steps that have each been proven at commercial scale: Dehydration, Oligomerization, Hydrogenation, and Fractionation." They claim on their website: "Ethanol can be produced from a variety of environmentally, economically, and socially sustainable sources such as biomass residues, municipal solid waste, or industrial waste gases with no competition with food, water, and land use, which permits SAF production anywhere around the globe."

In the Bloomberg article, however, Rathi writes:

"LanzaJet’s technology takes ethanol from sources such as sugarcane in Brazil, waste gas in China or corn in the US and then chemically converts it into SAF and renewable diesel. Depending on the feedstock used to make the ethanol, LanzaJet says the greenhouse-gas emissions from its SAF could be as much as 85% lower than conventional fuel."

That's a whole different kettle of kerosene. In an earlier post, "Can We Keep Flying on Sustainable Aviation Fuels?", we quoted a working paper, "Estimating sustainable aviation fuel feedstock availability to meet growing European Union demand," from the International Council on Clean Transportation (ICCT), which explicitly noted that, "even with strong policies in place, the limited availability of the best-performing feedstocks suggests that SAF production alone cannot achieve the EU aviation sector’s long-term GHG reduction obligations."

Andy Singer Cartoon about Ethanol

Andy Singer with permission

Making ethanol from sugar cane or corn is basically putting food in planes instead of people. This has been done for a while with gasoline for cars, but the tide was turning against this. In a recent post, "Is the Tide Turning Against Feeding Cars Instead of People?", we noted that many conservative and mainstream publications are starting to sound like Treehugger in their objections to this. Another Bloomberg writer, David Fickling, wrote that it's time to get biofuels out of your gas tank, noting that "the pressure it’s putting on the planet’s limited farmland is hampering our ability to feed the world’s poorest. It’s time to start dismantling the pipeline connecting farms to gas tanks before it does any more harm."

Other writers at the radical leftist Financial Times noted that biofuel mandates should be canceled because people need food first. "Hundreds of millions of people are at risk of 'hunger and destitution' because of food shortages caused by the war, the UN’s secretary-general warned last week. The total amount of crops used annually for biofuels is equal to the calorie consumption of 1.9bn people, according to data firm Gro Intelligence, highlighting the volume of agricultural commodities that could be diverted from energy use if the food security crisis worsened."

After reading this latest article about SAF, I contacted Dan Rutherford, aviation director at the International Council on Clean Transportation, who noted that the statement "greenhouse-gas emissions from its SAF could be as much as 85% lower than conventional fuel" referred to the best possible second generation fuels, and not from first generation fuels like corn or sugar cane. He says the UN has estimated that SAF from U.S. corn, for example, will reduce greenhouse gas emissions by just 10% compared to jet fuel. We have noted previously that it is much like the Andy Singer cartoon, and actually worse for the climate than gasoline.

“The theory behind LanzaJet’s approach is to use cheaper, less sustainable feedstocks to prime the pump for better fuels later,” says Rutherford. “But that strategy has clearly failed for road biofuels because advanced fuels haven’t been able to compete on price. Better to take the EU’s approach and ringfence incentives and investment around the best fuels from day one.”

In the earlier post, I concluded that it will never add up to something meaningful: "There just aren't enough dead cows and there is not enough land to keep us all up in the air." At least right now, they are competing with people for food in a world where climate change and war are causing shortages and price increases. I don't see how anyone could imagine that this is a good idea.