Calgren Renewable Natural Gas
At Calgren, we are leading the way in Renewable Natural Gas (RNG) production, converting organic waste into a powerful, low-carbon fuel. Through our advanced anaerobic digestion systems, we capture methane from dairy manure at 20 local, family dairies, preventing this potent greenhouse gas from entering the atmosphere. In alignment with our commitment to sustainable efficiency, the biogas captured at each of the dairy digesters is transported through a centralized gathering pipeline to our Pixley biogas upgrading facility where it is then purified and upgraded into pipeline-quality RNG.
This high-purity RNG is injected directly into the utility natural gas pipeline, where it’s used to fuel medium- and heavy-duty vehicles, providing a cleaner alternative to diesel and gasoline. Our RNG is fully compliant with California’s Low Carbon Fuel Standard (LCFS) and generates valuable credits, helping to reduce the carbon intensity of transportation across the state.
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Methane Captured at Local Dairies
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Purified & upgraded into pipeline-ready RNG
Injected into utility natural gas pipeline
MMBtu/Year Renewable Natural Gas Produced
Calgren produces more than 1,200,000 MMBtu of Renewable Natural Gas each year, enough to replace millions of gallons of diesel fuel. By replacing conventional fuels, this volume prevents tens of thousands of metric tons of CO₂ emissions annually, while also reducing methane from dairies that would otherwise escape into the atmosphere.
Together, these efforts play an important role in supporting California’s transition to low-carbon transportation and advancing statewide climate goals.
Community Impact
RNG development is a direct expression of Calgren’s pledge to innovate and engage with community challenges. Capturing methane and producing renewable energy from dairy waste turns a local issue into an environmental and economic opportunity—furthering our goal of sustainable solutions, resilient communities, and a cleaner future.
Supporting Local Agriculture
RNG projects provide new revenue streams for family dairies while helping them manage manure responsibly. The digestate returned to nearby farms improves soil health and keeps nutrients cycling within the community.
Reduced Emissions
By capturing methane and producing renewable fuel, RNG contributes to lower overall greenhouse gas emissions. When used in place of diesel, it offers a cleaner-burning alternative that supports California’s air quality and climate goals.
Jobs & Economic Growth
The construction and operation of digesters and upgrading facilities bring skilled jobs and local investment into rural communities.
At the same time, dairy digesters create an alternate income stream for local farms.
Education & Awareness
RNG facilities serve as living examples of circular economy solutions, offering inernships and opportunities for school groups, universities, and community organizations to learn about renewable energy and sustainable agriculture.
How Dairy Methane Becomes Renewable Energy
Want to dive deeper into the science behind it? Read our full breakdown of how dairy methane becomes renewable energy.
Integration with Other Calgren Systems
RNG production is tightly connected to Calgren’s other renewable systems. Methane captured from local dairies is upgraded into clean fuel, while the nutrient-rich digestate is applied to surrounding farmland as a soil amendment. Together with ethanol production and co-products, these connections demonstrate how Calgren’s technologies work in synergy to reduce waste and strengthen agriculture across the region.
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