BOSTON — For years, dairy farmers have used cow manure as fertilizer to spread over crops like corn and hay. But two farms in Western Massachusetts have a new use for all that manure — renewable energy. Luther Belden Farm in Hatfield and Rockwood Farms in Granville are embarking on a project to turn cow manure into electricity as a way to become self-sustaining and stabilize their finances in what they say is a volatile market. The farms are working in partnership with the the Hampshire Council of Governments and Pennsylvania-based startup Ag-Grid Energy. The farms hope to break ground on two on-site agricultural anaerobic digesters this summer.
“We’re just getting started. They say we’ll be breaking ground in June,” said Richard Woodger, 73, owner of Rockwood Farm. “The reason we’re doing this is to make ourselves more sustainable … We’ve seen a real downturn the last couple of years, and it doesn’t recover as fast as it falls.” Of the 7,755 farms in the state, only 155 are dairy farms, according to the Massachusetts Department of Agricultural Resources. It is not an easy industry to work in, dairy farmers say.
“Milk prices are very volatile, they always have been. It seems to be getting worse. The thing is, we’re sort of part of the world market, so we’re subject to world prices,” said Darryl Williams, 56, of Luther Belden Farms, which is about five miles northeast of Northampton. Williams said the digester is an approximately $2 million investment made possible with the help of a number of state and federal grants. The electricity produced by the digesters will power the farms, and leftover energy will be sold in the form of net metering credits to municipal entities in the Eversource customer zone. The Hampshire Council of Governments, a consortium of towns in Western Massachusetts based in Northampton, will facilitate the net metering credit sales, says HCOG Director Todd Ford.
“We love to support local business and local farmers, and we’re experts at setting up these systems of selling to towns, selling net metering credits,” Ford said. “This is part of our commitment to … local renewable energy.”
Ford said the energy generated by the two farms will be 5.3 million kilowatt-hours per year — enough to power some 10 municipal complexes like libraries, schools and town halls. To produce that energy, the two digester systems will treat 40 tons of waste per day, or some 14,600 tons a year. The Hampshire Council of Governments launched a similar net metering credit program to partner with those who generate solar power in 2015. That program has some 80,000 customers, Ford said.
The renewable energy generated by the dairy farms will be available for purchase at a 15 percent discount, Ford said, meaning towns will pay 85 cents for every dollar of energy they use. The Hampshire Council of Governments signed a contract to sell the energy May 19, and Ford intends to sell the net metering credits by the end of the summer. Granville, about 25 miles west of Springfield, is the first town to commit to powering its municipal buildings with credits produced by Rockwood Farms, Ford said.
To use the energy-producing digesters, farmers put cow manure and off-site food waste into a cement cylinder with a flexible, bladder-like top, explained Ag-Grid Energy CEO and Founder Raski Akki. Organisms in the digester “eat” the waste and emit biogas — methane and carbon dioxide. The gas rises and goes through pipes to a engine-like generator where it is burned and converted to electricity.
Akki says the digesters are well-suited to dairy farms because farmers can still use the manure as fertilizer after being processed by the digester. Akki estimates there are between 260 and 280 agricultural digesters in the United States. “It reduces odors at the farm, the farm doesn’t have to rely on the grid,” Akki said. “It fits well with local needs.”
After the process is complete, the manure and food waste will smell less pungent, something Williams says is a welcome change. He says he does not notice the distinct smell of his dairy farm, but others who live in the residential area near his farm do. Right now, Luther Belden farm keeps the animal waste in manure storages to be spread over crops in the spring and fall.
“We utilize as much as we can. It cuts down on the fertilizer bill. In some respects, we don’t have enough manure,” Williams said. He said accepting off-site food waste will increase the amount of material he can spread on his crops. The digester process will make that fertilizer more stable, he added, meaning it will stay more firmly in the soil. “Dairy farmers are kind of struggling,” Williams said. “Anything we can do to help sustain ourselves and sustain our land, to keep open spaces and productive farmland is a good thing.”