Aemetis Biogas

We produce Renewable Natural Gas that reduces methane and other greenhouse gas emissions while providing economic security to local dairies.

Aemetis Renewable Natural Gas (RNG) has a negative carbon intensity and is addressing the problem of harmful greenhouse gas emissions (GHG) while providing jobs and economic development. In 2020, the California Air Resources Board (CARB) approved Aemetis’s biogas pathway, utilizing a negative -426 carbon intensity score for the company’s first dairy digesters.

By the end of 2022, Aemetis will have seven operating dairy digesters with an additional 10 digesters in development or under construction, and a direct interconnection with Pacific Gas & Electric’s gas pipeline that will enable the gas to be transmitted statewide. With a fully built-out objective of constructing and operating over 60 dairy digesters, we estimate our RNG production will reach more than 1.5 million MMBTU annually by 2025.

Our RNG is produced by capturing methane from local dairies in California’s Central Valley, eliminating thousands of tons of harmful GHG emissions annually. Moreover, our RNG is produced continuously – 24 hours a day 365 days per year – without the intermittent issues inherent with some renewable energy sources such as wind or solar. RNG is pipeline quality gas that fits transparently into the existing natural gas infrastructure, making for a seamless transition from petroleum-based energy to negative carbon intensity clean fuels. As California has over 1,200 existing dairies, Aemetis is also providing additional economic security and environmental compliance for family farms in the region. Aemetis simultaneously provides jobs and cleaner air while contributing to our state’s climate objectives.

Aemetis produces RNG from dairy digesters throughout California’s Central Valley. Aemetis has built over 40 miles of underground biomethane pipeline that transports biogas to the company’s ethanol biorefinery in Keyes, California. At the biorefinery, the biogas is upgraded to pipeline quality RNG for distribution via an onsite interconnection with the PG&E gas pipeline or at an onsite RNG fueling station for use as renewable, below zero carbon intensity (CI) transportation fuel.

Our ability to fuel trucks with negative carbon intensity RNG will contribute to California’s goal of carbon neutrality by 2045 and will reduce transportation air pollution created by diesel emissions.

Aemetis Biogas


Aemetis Biogas LLC subsidiary formed to design, build, and operate dairy-based renewable natural gas (RNG) production and distribution assets.


Aemetis Biogas completes first two dairy digesters and four miles of private pipeline for Phase I of the dairy digester/RNG project. Begins utilizing dairy biogas at Keyes facility to replace petroleum natural gas.


Begins production of below zero carbon intensity dairy biogas.


Aemetis completes construction of dairy biogas-to-RNG gas purification facility; interconnection to PG&E gas pipeline; 5 new dairy digesters; 40 miles of private biogas pipeline; and begins construction of 5 new dairy digesters.


Signs multi-year supply agreement with Trillium to supply RNG for truck refueling stations.


Aemetis and PG&E hold ribbon cutting event for centralized biogas cleanup and renewable natural gas (RNG) interconnection with PG&E pipeline.

Why Renewable Natural Gas?

Methane is one of the most destructive greenhouse gases and has a global warming potential at least 25 times greater than Carbon Dioxide (CO2). According to the State of California, dairy and livestock account for approximately 50% of the state’s methane emissions.1

The Aemetis circular bio-economy efficiently utilizes agricultural byproducts and waste material to produce carbon negative transportation fuel. As part of the circular bio-economy, Aemetis supplies dairies with a protein rich animal feed that is a byproduct from our low-carbon ethanol facility. In turn, the dairy cows create waste methane that is captured and cleaned by Aemetis to produce Renewable Natural Gas — a below zero carbon alternative to petroleum-based diesel fuel. This circular bio-economy significantly reduces harmful greenhouse gas emissions while providing economic development and long-term financial stability for family farms.

To upgrade dairy methane biogas to Renewable Natural Gas, millions of dollars have been invested in the most advanced gas clean-up systems, pipelines, and infrastructure to create a pipeline quality replacement for petroleum natural gas and fossil-based diesel fuel.

Creating Renewable Natural Gas contributes to a higher quality of life for local communities by removing methane and other dangerous pollutants from the air. This is especially true for many disadvantaged California communities who have been consistently exposed to poor air quality in the state’s Central Valley region. Additionally, the Aemetis RNG projects create employment and economic development opportunities for local residents. Dairies’ primary income are the milk products that the cows produce, a commodity that has experienced fluctuating price spikes and lows. Methane capture helps bolster the bottom line for these dairies, ensuring economic security and a buffer against fluctuating commodity prices for our rural economy.

Aemetis Biogas By the Numbers


Year Started Producing

1.5 million

Expected MMBTU Produced Annually by 2025