Cow Manure, Methane, and the Race to Make Sustainable Jet Fuel from California Dairy Farms

A California startup operating near Madera in the San Joaquin Valley is capturing methane from decomposing dairy cow manure and converting it into certified sustainable aviation fuel. The process is not a pilot program or a lab experiment - it is producing fuel that meets ASTM Jet-A specifications and can be blended into commercial aircraft fuel systems today. It represents one of the more promising feedstock pathways in an industry scrambling to close a massive gap between SAF supply and the demand that regulatory mandates are about to create.

Why Aviation Has a Carbon Problem That Won’t Solve Itself

Commercial aviation currently accounts for somewhere between two and three percent of global CO2 emissions. That figure sounds manageable until you account for the growth trajectory. The International Air Transport Association (IATA) projects that number could triple by 2050 if nothing changes, driven by increasing air travel demand across Asia, Africa, and Latin America.

The industry has responded with a headline commitment: net-zero carbon emissions by 2050. The fine print is that most of the roadmap depends on sustainable aviation fuel. Aviation runs on kerosene - specifically Jet-A and Jet-A 1 refined from crude oil. When burned, that fuel releases carbon that was locked underground for millions of years. There is no battery technology on the horizon that can displace liquid hydrocarbons for anything beyond short regional routes. The energy density of jet fuel - the amount of energy it carries per pound - is what makes intercontinental flight possible, and SAF preserves that density.

What Sustainable Aviation Fuel Actually Is

SAF is jet fuel. It meets the same ASTM specifications as conventional Jet-A, works in existing engines, existing fuel systems, and existing aircraft without modification. The difference is carbon origin. Instead of pulling carbon from ancient crude oil, SAF is made from materials that contain carbon already cycling through the current atmosphere - agricultural waste, used cooking oil, municipal solid waste, and animal waste. The carbon released when SAF burns was recently in the atmosphere anyway, which is why lifecycle emissions can be as much as 80 percent lower than conventional jet fuel.

Under current ASTM certification, SAF can be blended with conventional jet fuel up to a 50 percent ratio. That is the ceiling for today’s commercial operations. The industry is working toward 100 percent SAF certification, but the 50/50 blend is what is flying in test programs and some commercial routes right now.

How a Dairy Farm Becomes a Fuel Source

California has approximately 1.7 million dairy cattle, concentrated heavily in the San Joaquin Valley, one of the most productive agricultural regions on earth. The state produces around 39 billion pounds of milk per year. Those animals produce an enormous volume of manure, and decomposing manure releases methane.

Methane matters here for two reasons. First, it is a significantly more potent greenhouse gas than carbon dioxide over a 20-year horizon - leaving it unmanaged is worse for the atmosphere than burning it. Second, capturing and converting it creates a double benefit: you prevent the methane release and you displace the need to refine crude oil.

The technology the Madera startup uses starts with an anaerobic digester - a system where manure is broken down by microbes in an oxygen-free environment, producing biogas that is primarily methane. Dairies have used digesters for decades to generate on-farm electricity. The new step is what comes next: processing that raw biogas through a chemical conversion pathway - approaches such as Fischer-Tropsch synthesis or methanol-to-jet (MTJ) - to produce hydrocarbon chains that meet aviation fuel specifications.

Why Dairy Biogas SAF Has the Best Carbon Numbers

The lifecycle carbon accounting for dairy biogas-derived SAF is among the strongest of any SAF production pathway. Some analyses show it achieving a negative carbon intensity score - meaning the fuel actually reduces net atmospheric carbon compared to the baseline of doing nothing, because you are preventing potent methane emissions and simultaneously displacing fossil fuel refining.

That is the kind of number that gets airline procurement teams interested. It also matters for regulatory compliance under the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), the ICAO framework that requires airlines on international routes to offset emissions growth above a baseline. SAF credits count toward CORSIA compliance, and low-carbon-intensity SAF generates more credits per gallon.

The Regulatory Landscape Driving SAF Demand

Demand for SAF is not purely voluntary. The European Union’s ReFuelEU Aviation regulation requires fuel suppliers at EU airports to blend increasing percentages of SAF into the fuel supply - 2 percent beginning in 2025, scaling to 70 percent by 2050. Any airline serving European airports is already operating under a SAF cost mandate.

The Biden administration set a goal in 2021 of producing 3 billion gallons of SAF per year by 2030 and enough to fully supply domestic aviation by 2050. To calibrate how far off that target remains: the United States used approximately 20 billion gallons of jet fuel in 2023. Total global SAF production that same year was under 300 million gallons. The gap is not incremental - it is structural.

The Economics: What Makes or Breaks SAF at Scale

Conventional Jet-A runs roughly $1.50 to $3 per gallon at the wholesale level depending on market conditions. SAF typically costs two to five times more, sometimes higher. At those prices, SAF cannot function as a wholesale replacement for conventional fuel. It is a supplement, a compliance tool, and increasingly a premium product that some airlines are purchasing under long-term offtake agreements that provide price certainty.

California’s Low Carbon Fuel Standard (LCFS) is part of what makes the Madera project viable. The LCFS creates tradeable credits for fuels with low carbon intensity. Aviation fuel produced from dairy biogas can generate LCFS credits with real dollar value, improving the economics enough to justify the capital investment.

At the federal level, the Inflation Reduction Act of 2022 included a SAF production tax credit - the SAF blender’s credit - worth up to $1.75 per gallon for SAF meeting certain lifecycle carbon reduction thresholds. That credit is available through 2027 under current law and has accelerated investment in SAF infrastructure across the country.

What This Means for the Broader SAF Supply Chain

Used cooking oil is currently the dominant SAF feedstock globally. It has a well-understood conversion pathway and favorable carbon scores. The problem is that supply is finite - you cannot scale SAF to the volumes the industry needs on used cooking oil alone. That is why the industry is looking hard at agricultural waste, forestry residues, municipal solid waste, and animal waste.

The San Joaquin Valley’s dairy biogas potential is not trivial. If the technology the Madera startup is demonstrating can be deployed across a significant portion of California’s dairy industry, the feedstock volume is substantial.

World Energy operates a SAF refinery in Paramount, California, currently supplying SAF to Los Angeles International Airport. United Airlines, Delta, American, and Southwest all have SAF purchasing programs. Boeing and Airbus have both certified current production aircraft to fly on SAF blends. The commercial infrastructure is being built in parallel with the production ramp.

What Pilots Need to Know Right Now

For turbine operators - Citations, King Airs, Phenom series, and anything else with a turbine up front - SAF blends are increasingly available at FBOs at larger airports. SAF is fully compatible with existing turbine aircraft and fuel systems. If your FBO offers it, there is no operational reason to avoid it.

For piston pilots, SAF is adjacent to the unleaded avgas transition, which operates on a different certification framework and different production chemistry. The underlying principle is similar - the aviation fuel supply is in transition - but the timelines, regulations, and products involved are distinct.

For anyone who cares about the long-term viability of aviation as an industry, the Madera project matters as evidence that the production technology works. The question is not whether dairy biogas can become jet fuel. It is happening now. The question is whether it can scale fast enough to matter.

Key Takeaways

Global SAF production in 2023 was under 300 million gallons against 20 billion gallons of annual US jet fuel consumption - the supply gap is the central challenge for the industry’s net-zero commitments.
Dairy biogas SAF can achieve a negative carbon intensity score by preventing potent methane emissions while displacing crude oil refining - among the best lifecycle numbers of any SAF feedstock.
A startup near Madera, California is producing jet-specification fuel from San Joaquin Valley dairy manure today, supported by California’s LCFS credit market and the federal SAF blender’s credit of up to $1.75/gallon.
SAF is currently certified for blending up to 50 percent with conventional Jet-A and is fully compatible with existing aircraft and fuel systems - no modifications required.
The EU’s ReFuelEU mandate (2% SAF blend in 2025, 70% by 2050) is already affecting fuel costs for airlines serving European airports, making SAF procurement a near-term operational reality, not a future-state consideration.