California's Aemetis Biogas achieves milestone in RNG production
California-based renewable natural gas (RNG) company Aemetis announced on June 26 that its subsidiary, Aemetis Biogas, has completed a milestone by constructing and operating dairy digesters with a capacity to produce more than 300,000 mmBtu/year of RNG.
The planned construction of new digesters is expected to increase the annual RNG production rate to over 800,000 mmBtu/year by the third quarter of 2025, representing more than a 150% increase from the current production rate.
Eric McAfee, CEO of Aemetis, noted that 300,000 mmBtu/year of RNG generates revenues of about $13mn/year. “We have already closed $50mn of 20-year USDA-guaranteed funding for the biogas project, achieved positive cash flow from biogas operations, and we are working to close an additional $75mn of USDA-guaranteed construction funding this year,” he said.
Aemetis has designed its RNG production infrastructure for cost-effective expansion. An Aemetis-owned pipeline transports biogas from dairy digesters to a centralised RNG upgrading facility at the Aemetis Keyes ethanol plant. The company has already installed 36 miles (57.9km) of biogas pipeline and plans to add another 24 miles, bringing the total to 60 miles.
Currently, Aemetis has agreements to obtain dairy waste from 43 dairies and aims to increase its RNG production at its current upgrading hub to more than 1.65mn mmBtu/year of negative carbon intensity transportation fuel. This quantity of RNG is projected to reduce greenhouse gas emissions equivalent to 6.8mn tonnes of carbon dioxide over ten years.
The Aemetis Biogas project, which includes dairy digesters, a collection pipeline, a centralised biogas upgrading facility, a planned RNG fuelling station, and a gas pipeline interconnection, is expected to invest more than $300mn in California’s Central Valley.
In March this year, the company secured approval from the US Citizenship and Immigration Services (USCIS) of $200mn in funding for its projects aimed at advancing sustainable aviation fuel (SAF), RNG from dairy sources, carbon sequestration, and energy efficiency upgrades to its Keyes ethanol plant.