PHOTO: PG&E
fuel
This biogas refining system was installed at the Vintage Dairy farm in Fresno County, Calif. This project went live in March and was the first biogas-to-pipeline injection project in California.
mental protection. In May 2006, the company adopted a policy statement to the effect that it would not only seek to minimize its greenhouse gas emissions, but would also become a leader in addressing global climate change with responsible policies and programs. “Our commitment to renewable energy is pretty solid,” says Ken Brennan, a senior project manag-
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er in PG&E’s business development division. “We are trying to get any kind of nonfossil-fuel-based renewable energy we can into our portfolio.” One way to expand its efforts to reduce its greenhouse gas emissions is the integration of biogas into its gas distribution system. The first stage in the process is a project in California’s dairy country involving the anaerobic digestion of manure. “We have been working with dairies in the San Joachin Valley to connect them with our transmission system,” Brennan says. The initial project centered on converting the manure into biomethane and creating a system that could clean up the gas at the farm level so it could be injected into the existing gas pipeline system. “Some dairies are already capturing methane from their covered digestion ponds,” says Rod Boschee, manager of PG&E’s business development division. “They are burning it on-site in combustion engines to produce electricity to use on the farm. That is certainly a step in the right direction but we feel a more efficient use of that gas is to clean it up and put it in a pipeline.” The first dairy in the project began biomethane production in April, and the gas it produced is being tested to ensure that it meets the standards for pipeline gas. The dairy is expected to produce about 600 Mcf of gas per day, and plans call for three or four neighboring dairies to eventually tie into the same system.