Farmers look to turn manure into sustainable energy
Daily Hampshire Gazette
By REBECCA EVERETT
Monday, February 4, 2013
DEERFIELD — At Barway Farm, the 250 milk cows produce a whopping 1,628 gallons of milk a day. They also produce about 5,480 gallons per day of another substance, said farmer Peter Melnik, but this one doesn’t do a body good. It’s cow manure.
Melnik and a few other innovative farmers in the area will soon be able to combine the manure with food waste to produce sustainable energy, as well as a quality fertilizer that smells a whole lot better than the alternative. He said he expects his $3.5 million anaerobic digester will be transforming the waste by the end of the year. Another digester is also under construction at Barstow’s Longview Farm on Route 47 in Hadley.
“We have this product — cow manure — and if we can extract more value from it, that just makes sense,” said Melnik, the fourth generation co-owner of Barway Farm. “We can get more value out of the back end of the cow.”
The technology of the anaerobic digester is not new; waste treatment plants have been using it for years as a way to dispose of sludge waste that reduces the amount of waste going to landfills while limiting greenhouse gas emissions and producing energy. Inside the heated digesters, microorganisms naturally break down biodegradable material in the absence of oxygen, producing methane, which can then be used to produce electricity.
It is, however, a relatively new development in the Massachusetts dairy farming community. A few factors have made the price tag of a digester a lot easier to swallow for farmers, as well as municipalities that are eyeing their use. These factors include state and federal grants, a commercial interest in buying sustainable energy credits, and the state Department of Environmental Protection’s plans to ban commercial entities from disposing of food in landfills, said Alicia Barton McDevitt, chief executive officer of the Massachusetts Clean Energy Center. The quasi-public agency awarded $400,000 grants for each of the two digesters at the farms in Hadley and Deerfield.
“It’s become clear that this is a technology with a lot of potential to hit multiple benefits: waste disposal, generating clean energy and creating a by-product fertilizer,” McDevitt said. “And the DEP’s signaling that it will ban disposal of commercial food waste puts an emphasis on the need to find alternative disposal.”
Melnik said he believes the digester will make manure “just another crop” on his farm on Mill Village Road.
The efforts to create the dairy farm digesters began five years ago, when William Jorgenson, a Boston resident with over 10 years of experience building non-agricultural digesters, started AGreen Energy, LLC in Boston.
AGreen Energy is a consortium of three partners and five partner farms, including Barway and Longview farms, that oversees the digester projects at those farms. So far, only Jordan Farm in Rutland has a working digester, but after completing the two projects in the Pioneer Valley, Jorgenson said AGreen Energy will switch its focus to two new digesters at Hager Brothers Farm in Colrain and Woodger Farm in Granville.
“This technology has been on farms in Europe for 20 or 30 years because electricity rates were high there. They’re just getting high enough here,” Jorgenson said in a telephone interview Friday. “Now there’s kind of a boom happening here with digesters.”
Jorgenson said that based on the number of cows, Barway and Longview farms will see the same kind of results that Jordan Farm has since its digester was finished 1½ years ago. Each day at the Rutland farm, which milks about 350 cows, two tanker trucks bring a total of 45 tons of liquefied food waste to the farm. It is added to a sealed tank containing about 25-30 tons of manure and the mixture takes between 28 and 35 days to break down.
“This is just composting done mechanically,” he explained.
Each day, the digester produces around 6,000 kilowatt hours of electricity, enough to power the average American home for 134 days, according to AGreen Energy’s website.
The digesters are owned by AGreen Energy, and all the farms are partners in the LLC. Each farm signs a 20-year contract with AGreen that states that in exchange for the fertilizer and heat that are by-products of digestion, it will provide the site and manure for the digester and purchase 10 percent of the energy it produces for a locked-in rate that Jorgenson said is about 25 percent of the market rate.
“And they’ll save even more as energy rates go up as they’re predicted to,” he said.
AGreen sells the remaining 90 percent of electricity to the grid in exchange for sustainable energy credits. It then sells those credits to companies who can say they use sustainable energy.
Big food companies, such as Cabot, Hood and Cains, pay a “tipping fee” similar to those charged at commercial waste facilities to bring their food waste to the Rutland digester.
The process is complex, but it’s a no-brainer once you consider the benefits, said Melnik.
“I was skeptical at first, but when you dig into it, it just makes so much sense,” he said, recalling the time four years ago when Jorgenson approached him about building a digester. “Environmentally, it makes so much sense. My 10-year-old son said he hopes someday he can drive an electric tractor up to the digester, plug it in and then go to work.”
Jorgenson said he approached a number of “forward thinking” farmers whose operations fit certain criteria, from the kind of bedding used in the stalls to the number of cows — 250 minimum.
Being a multi-generational farm where future generations are likely to keep things running helped, Melnik added. Barway and Longview farms made the cut.
David Barstow, co-owner of Longview Farm, said he was also unsure of the project at first, mostly because of the amount of capital required to build. “The concept is good, it’s just all about the money,” he said.
Barstow’s Longview Farm is a six-generation farm that milks about 225 cows on Hockanum Road.
“I’m hoping to have another source of income,” he said. “Digesting manure is good for the environment and it will help our bottom line, and that will be good because things are tight.”
Another incentive was the potential for gallons of high quality, nearly odorless fertilizer to use on Longview Farm’s 200 acres of hay.
“We’re hoping to use it on the hay crop in the summer,” Barstow said. “We don’t usually spread manure in the summer because of the smell.”
Melnik said his neighbors were pleased to hear that the digesting process reduces the smell of the manure by 90 percent, because most of the odor comes from the methane it gives off.
The digestion also breaks down the nitrogen in the manure into a form that is much easier for plants to use, Jorgenson said. Last summer, after a year of spreading the digester fertilizer, Jordan Farm doubled its hay production and did not need to use any chemical fertilizer, he said.
Weighing cost, risks and benefits
It will take the farms about 8 or 9 years to pay off the cost of building the digesters, Jorgenson said.
Coming up with the initial $3.5 million to build is not easy, either. The projects have secured the $400,000 grants from the Massachusetts Clean Energy Center and grants of equal size from the U.S. Department of Agriculture’s Natural Resources Conservation Service. AGreen expects more funding from an energy grant program created by the The American Recovery and Reinvestment Act. The remaining funding comes from AGreen partners and loans from the Farm Credit Bank, Jorgenson said.
Melnik said the only risk he can see with the project is that there could be more competition for food waste in the future if municipalities or the private sector start building digesters. He thinks that dairy farms would still have the edge, though, because fertilizer created at wastewater treatment plants cannot be used on food crops because it contains human waste.
One of the “hardest questions” he and Barstow are facing, besides financing, is how to find food waste to supplement the manure. The digester has to have the right balance of manure and food waste for the enzymatic breakdown to work properly, he said.
He is hopeful about working with companies that produce dairy products, like Cabot and Garelick Farms, because it would create what he calls a “local biosystem.”
He gave the Cabot processing plant in West Springfield as an example. “Milk comes from my farm or Barstow’s, goes to the plant to be made into butter, and then the milk by-product comes back to the farms. We use it to make electricity and fertilizer, the plant buys electricity from us and we spread the fertilizer on the fields. The crops grow, the cows turn them into milk,” he said.
“That’s a neat mini-biocycle,” he said. “We can complete the loop all within about 25 miles of the farm.”