A program in California to turn cow manure into renewable natural gas will help dairy farmers reduce methane emissions while potentially creating new economic opportunities.
The project will produce renewable natural gas (RNG) by capturing methane from 15 dairy farms in Merced County and then conducting anaerobic digestion. The project is being funded primarily through the California Public Utilities Commission’s Dairy Biomethane Pilot Program, which was established as part of the state’s strategy to reduces emissions, including from methane gases.
The program is also being conducted through a partnership with Pacific Gas and Electric (PG&E), Maas Energy Works and California Energy Exchange (CEE).
Historically a lack of access and cost-effective alternatives to transport RNG to PG&E’s pipeline system has hindered similar efforts with dairies, according to PG&E. The CEE pipeline is privately operated and can help remote dairies with the infrastructure to connect to an economically viable source of renewable energy through the PG&E pipeline system.
Manure management programs can also reduce emissions at a relatively low cost.
Estimates by the California Climate Investments found that such efforts have resulted in 29% of emissions reductions, but used only 2% of investments provided to make overall climate improvements in the state. Additionally, anaerobic digesters are seeing widespread implementation because they are cost effective and farmers can receive carbon credits for reducing their emissions. Additionally, they can use or sell the energy they produce from them, according to Palo Alto Online.
Approximately 55% of California’s methane emissions come from dairies and livestock, according to the California Air Resources Board 2018 Greenhouse Gases Emissions Inventory.
For the Merced County project, once the anaerobic digestion takes place, the RNG is transported to PG&E’s gas system via CEE’s pipeline where it is introduced at a receiver station. From there the Maas Energy project, which includes gas production and cleaning equipment as well as the interconnection facilities, moves the RGN from farms into the transmission pipelines.
The project is part of a growing biogas market, which is expected to hit $61 billion by 2031. Dairy biogas contains up to 65% methane. Efforts similar to the Merced County project are expanding across the United States.
Other projects in California have turned manure from dairy cows into fuel cells for electricity production, and a project in Arizona is expected to make enough RNG from dairy waste to produce 1.6 million gasoline gallon equivalents. A similar project in South Dakota is expected to produce 650 million cubic feet of RNG a year when it is completed in 2024.
The RNG from Maas Energy’s facilities in Merced began flowing into the PG&E gas transmission system in mid-December.
“Merced County is the nation’s second largest dairy county and we expect this project will make Merced a leading producer of renewable transportation fuels as well,” says Maas Energy CEO Daryl Maas.