Digester Continued from Page 4
One of the company’s most recent operational digesters is located at AC Machado Dairy in Crows Landing, the fi- nal stop on the tour. The 1,800-cow dairy completed construction on its digester in March. That Aemetis was able to get per- mitting for its 40-mile biogas pipeline in about a year “was a pretty remark- able feat,” Foster said. Working with Stanislaus and Merced counties, the company was able to put the pipeline in the public right of way alongside of the road with other utilities, which “saved us a lot of hassle of having to try to get easements from individual landowners,” he added. “By being in the public right of way, we have to be safer. We have to follow the same standards that the utilities have to follow,” Foster said. The first four miles of the pipeline cost $1 million a mile, with the last 40 miles costing $465,000 a mile, according to CEO Eric McAfee. Biogas pipelines are currently not regulated, said Robbie Macias, Aemetis’ vice president of biogas. But he said the company has “taken all the steps” through third-party engineer- ing inspections and testing to have a utility-grade pipeline “in the name of public safety.” (Ching Lee is an assistant editor of Ag Alert. She may be contacted at clee@cfbf.com.)
engines that powered generators to produce electricity for use on the farm. Today, Fiscalini’s manure manage- ment and methane digestion remain about the same: The farm uses a flush system to collect the manure in a cov- ered lagoon. The manure is then piped to the digester to produce methane gas. But rather than creating electricity, the biogas is now converted to low-carbon fuel. Eventually, the fuel can be injected into a natural gas pipeline. Fiscalini said renewable fuels pro- duction tax credits available for this type of system are “far better” than for converting methane gas to electricity. Back when the farm built its first digest- er, there were no such credits or pro- grams available. “Producing electricity was kind of the only option that we had,” he said. Back then, the technology to convert methane gas to natural gas wasn’t prov- en or readily available, Fiscalini said. Also, the nearest natural gas pipeline was more than 2 miles away from the farm, and putting one in the ground would have cost $1 million a mile, plus an additional $2 million one-time fee to connect to Pacific Gas & Electric Co., he pointed out. While those costs hav- en’t changed much, the tax credits have changed to make such an investment feasible today, he added.
Robbie Macias, from left, vice president of biogas for Aemetis, with company President Andy Foster and CEO Eric McAfee stand on top of a covered lagoon where biogas is made at AC Machado Dairy in Crows Landing.
By shifting to making low-carbon fuel, he said, the dairy could potentially power a fleet of trucks and “work directly with somebody versus working with the utility grid system.” “California’s already pretty good at pro- ducing electricity,” he said. “For a dairy farm to try to become a utility doesn’t really make a whole lot of sense.” The tour group then visited Aemetis’ ethanol biorefinery in Keyes, where biogas produced by Central Valley dairies is transported via its 40-mile un- derground pipeline. The biogas is then
upgraded to renewable natural gas and goes to PG&E via another pipeline. The biogas can also be used as a replace- ment fuel for diesel or converted to electricity to fuel electric vehicles, said Aemetis President Andy Foster. The company’s goal, Foster said, is to build 66 dairy digesters. About 30 dairies have signed up. Digesters on two dair- ies—with 1,800 cows and 3,700 cows— have been online since 2020. Five more are expected to come online by the end of the year, with five new ones starting construction next year, he said.
10 Ag Alert November 9, 2022
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