Twofold Renewable in Tulare County
by Keith Loria (Biomass Magazine) California’s Calgren Renewable Fuels uses renewable energy generated onsite to power its renewable fuel production process.
When the Calgren Ethanol Biodigester officially opened in Tulare County, California, early this year, it represented a major commitment by the state of California to employ sustainable energy production.
Located in the town of Pixley, the biodigester utilizes waste from dairy operation Four J Farms to power the production of tens of millions of gallons of ethanol, all consumed in the Central Valley. It is the first digester of its kind in the state, relying on agricultural waste to create renewable natural gas to power another renewable energy facility, essentially creating a zero-waste life-cycle.
There were some unforeseen challenges after the idea was conceived, so the project took a little longer to come to fruition than (Calgren’s president, Lyle) Schlyer had anticipated. “Satisfying California’s Environmental Quality Act was by far the biggest challenge,” he says. “Unfortunately, CEQA can be easily highjacked and used for unintended purposes. In our case, it was used to oppose an environmentally sound project.”
Van Ornum (Melissa Van Ornum, vice president of marketing for DVO Anaerobic Digesters) notes that permitting in California is never easy. “The fact that Calgren already had the steam turbine in place—so we weren’t having to permit a new engine—was a huge help,” she says. “They had to get a new permit, but it was more like modifying an existing one. That made it a lot easier.”
Another challenge was the community wasn’t originally on board and needed some convincing to assuage their concerns. Van Ornum says that educating the community played a large part in getting the project up and running. “Many were concerned,” she says. “Few knew anything about digesters, and we needed to explain that it wouldn’t explode, there were no crazy odors, and all these other things that people worry about. It helped that we could explain what it was and it didn’t take long for people to come around.”
Mostly, it was the fear of the unknown, Schlyer adds. “Our opponents were concerned about odors and the idea of waste processing in their vicinity,” he says. “To help allay their concerns, we downsized and tightened up project parameters. We also agreed to relocate the digester from the north side of our facility to the south side.”
The project was conceived in late 2009, and all CEQA issues were finally resolved in February of 2014. “We commenced construction immediately thereafter, and had the digester in operation by September 2014,” Schlyer says. “Initially, we hoped biogas would provide up to 20 percent of our fuel requirements, but we have had to pare back our expectations.”
The plant officially opened in February.
The digester greatly reduces bacteria and pathogens so dairy farmers can reuse the liquids (water) safely on their crops, Schlyer says.
The pipeline that sends the raw manure to the digester also pipes back the digester liquid into the lagoon, which is used on crops, Van Ornum further explains. “In California, where drought is a problem, the farmer has liquid and they can play Mother Nature. It allows for more flexibility for the dairy farm as well.”
The Pixley Biogas anaerobic digester is the first anaerobic digester on a California farm permitted to use all feedstocks, including municipal green waste and food processing waste.
Apol (Mike Apol, Regenis’ regional manager for California and project manager for the Pixley Biogas Project) notes that Reginis’s mission is to reimagine reusable resources, and in California, the potential is nearly limitless. He believes that implementing digesters around the state would not only create hundreds of new construction and operation jobs in rural communities, but that organic waste is in such supply that it could power up to three million homes, or generate 2.5 billion gallons of clean, ultra-low carbon transportation fuels.
Other examples include United Ethanol, which installed an anaerobic digester in an ethanol plant in Milton, Wisconsin, in 2010; and AG Processing Inc., which has an ethanol plant in Hastings, Nebraska. And the first three commercial-scale cellulosic ethanol plants that are in varying stages of commissioning in the U.S. have all added digesters on site and are utilizing them for process energy as well.
According to Schlyer, digesting waste at ethanol plants makes a lot of sense, especially if there are cattle nearby. “I would not be surprised to someday see waste digesters at a majority of ethanol plants,” he says.
Others in the industry aren’t so sure, perhaps suggesting that they aren’t a good fit for all operations. “You must recognize that offsetting your natural gas with a biodigester is an enormous undertaking,” says one industry insider, who requested anonymity. “We’ve had several problems with ours—we had struggles. It’s a very difficult economic proposition, unless you have a strong feedstock source. Most of the time that needs to be free.” READ MORE