Two Maine companies team up to convert food waste into clean energy
Photo / James McCarthy
Dan Bell, general manager of Agri-Cycle Energy, and Adam Wintle, managing partner of Exeter Agri-Energy, are poised to accept more food waste as feedstock for the two 400,000-gallon anaerobic digesters located at Stonyvale Farm in Exeter.
Photo / Courtesy Agri-Cycle Energy
Stonyvale Farm, the state's second-largest dairy farm, is shown in this aerial view with the two anaerobic digesters operated by Exeter Agri-Energy and the new $1 million food-waste-processing faciity operated by Agri-Cycle Energy.
Photo / Courtesy Agri-Cycle Energy
Agri-Cycle Energy installed this fall the state's first "de-packager" at its new $1 million food-waste-processing facility in Exeter. The de-packager strips the packaging off food waste before it's sent to the anaerobic digesters to mix with cow manure and eventually produce bio-gas.
Photo / James McCarthy
An Agri-Cycle Energy trailer dumps a load of food waste at the new $1 million Exeter food waste processing plant.
For several years now, Adam Wintle and Dan Bell have been pitching the concept that burying food garbage in landfills is a huge waste of a renewable energy source with numerous environmental benefits. That message wasn't exactly embraced, they say, by the garbage haulers, commercial landfills and trash-to-energy companies that didn't want to divert food waste tonnage from their revenue streams.
So Wintle and Bell did what any entrepreneur with a disruptive business idea would do: They created their own company.
Since mid-2013, Agri-Cycle Energy has been delivering food waste collected in Maine, Massachusetts and New Hampshire as additional feedstock for the two 400,000-gallon anaerobic digesters operated by Exeter Agri-Energy, the company Wintle and his siblings created in 2011 to transform cow manure and other organics into bio-gas as a way of assuring the continuing financial security of their extended family's neighboring 1,000-milking cow Stonyvale Farm.
The recent completion of a $1 million food waste processing plant — featuring Maine's first “de-packager” that separates discarded, damaged or expired food products from their boxes, cans or cartons — puts both companies in a strong position to capitalize on a growing national movement to reduce the amount of food going into landfills. The de-packager makes it feasible for supermarkets, hospitals, food manufacturers and even municipalities to send food waste to Exeter knowing that it will become a source of renewable energy instead of buried garbage rotting in a landfill.
“We never intended to be a food waste collection company,” says Wintle, who is managing partner of Exeter Agri-Energy and the principal owner of Agri-Cycle Energy. “We learned quickly that there wasn't a community of haulers that had an interest in transporting food waste to this facility, because they have an interest in controlling that tonnage and sending it to landfills and waste-to-energy plants that benefit from that tonnage. We were, more or less, a 'threat' to their interests.”
“We now have the operating infrastructure in place to really execute,” he adds. “The last year has been not only building equipment resources but personnel resources as well to have an effective team from soup to nuts. We really are in position now, we have all the functions covered, and at this point we're saying, 'Let's go get the waste.'”
Converging interests
Wintle and Bell's food-waste-as-renewable-energy sales pitch dovetails with a growing push by the federal and state governments to reduce food waste and especially keep it out of landfills.
On Sept. 16, Environmental Protection Agency Administrator Gina McCarthy joined with Department of Agriculture Secretary Tom Vilsack to announce the United States' first-ever national food waste reduction goal, which calls for a 50% reduction by 2030. “By reducing wasted food in landfills, we cut harmful methane emissions that fuel climate change, conserve our natural resources and protect our planet for future generations,” McCarthy said at the launch of the initiative.
The two federal agencies single out anaerobic digestion and bio-gas production as key components of “cross-cutting strategies” to achieve national economic and environmental goals that include:
- Reducing greenhouse gas emissions by capturing and burning methane, thereby decreasing its production and release at landfills
- Generating renewable energy, thereby reducing dependence on fossil fuels
- Advancing sustainable development by producing a local source of renewable heat and electricity
- Creating nutrient-rich soil amendments that can be used instead of some conventional fertilizers.
In December, U.S. Rep. Chellie Pingree, D-1st District, introduced “A Food Recovery Act” bill that includes nearly two dozen provisions to reduce food waste across the country. In addition to removing barriers that prevent the donation of surplus food, Pingree's bill supports “food-waste-to-energy projects at the farm, municipal and county levels” by creating “an infrastructure fund to support construction of large-scale composting and food waste-to-energy facilities in states that restrict food waste going to landfills.”
Since Oct. 1, 2014, Massachusetts has imposed a food waste ban on commercial businesses and institutions that dispose of one ton or more of food or other organics per week. Bell says that law provides a major boost to Agri-Cycle Energy's food collection tonnage, with Massachusetts General Hospital, the Seaport Hotel and World Trade Center, Fidelity and a variety of restaurants and institutions sending their food waste to Exeter Agri-Energy as feedstock for its anaerobic digesters.
Finally, Maine's failure to achieve a statewide 50% recycling rate by 2014 as required by an earlier law, is spurring a closer look at composting and anaerobic digestion as key solutions to meet that goal. That's because almost 30% of almost 1.8 million tons of municipal solid waste in the state is discarded food, according to the Maine Department of Environmental Protection.
“In just the last three years we've seen tremendous forward momentum through the food waste ban in Massachusetts, the conversation with Augusta and the general public in Maine who want to divert organics and increase our recycling rates,” says Bell, a partner with Wintle who serves as Agri-Cycle Energy's general manager. “All of that's right in line with the type of things that are going to help our business continue to succeed and create renewable power and do things that are socially, environmentally and economically friendly to this region.”
Achieving the right balance
When Exeter Agri-Energy went online with its anaerobic digesters in early 2012, it had a ready supply of cow manure from the 1,000 milking cows and another 800 or more heifers, calves and “dry” cows at the adjacent Stonyvale Farm to jumpstart its closed loop energy-producing system. But food waste has always been part of the feedstock mix of about 30,000 gallons pumped daily into the two 400,000-gallon digester domes just below the dairy barns. The ideal blend is 50:50, but Wintle says the Exeter digesters are averaging 20,000-plus gallons of manure and 10,000 gallons of food waste per day for a 75:25 blend.
Wintle and Bell expect the de-packager will spur higher volumes of food waste coming in, since it has the capacity of processing up to 20 tons of food waste an hour. That will help Exeter Agri-Energy achieve the optimum blend of feedstock going into its digesters. Any extra volume beyond what's needed in the daily mix can be stored in one of the 26,000-gallon storage tanks for pumping later on into one of the domed anaerobic digesters in carefully controlled amounts with cow manure. The anaerobic fermentation process takes about a month to complete, with the methane-rich bio-gas being burned onsite to create heat and power a generator that sends electricity to the grid under a 20-year power contract at 10 cents per kilowatt hour.
“Today Agri-Cycle manages on the order of 25,000 tons per year of food waste, “ Wintle says, noting its client list in Maine includes Hannaford, Whole Foods, Colby College, Walmart, Fore Street Grill, Street & Co. and AdvancePierre Foods, owner of the Portland-based Barber Foods, which makes stuffed chicken breasts and other chicken products. “Exeter as a facility can handle upwards of 50,000-plus tons per year, on its own.”
Bell quickly adds that even if the food waste volume eventually exceeds the capacity of Exeter's two digesters, Agri-Cycle Energy is building a network of other anaerobic digester companies in New England that might need additional food waste for their own operations. “We're providing, in effect, an overflow mechanism for this food waste to be processed later on here or at other facilities,” he says.
The de-packager's ability to efficiently separate packaging from expired or damaged foods has already benefited Hannaford, which has 188 stores in Maine, New Hampshire, Massachusetts, Vermont and New York and is one of Agri-Cycle Energy's primary customers.
The Scarborough-based supermarket chain received the Grocery Stewardship Certification from the Manoment Center for Conservation Sciences in early 2015 for its sustainability practices, which included the diversion of 125 million tons of waste from landfills that prevented more than 430 million pounds of greenhouse gases from being emitted. Company spokesman Eric Blom says the company's efforts to reduce food waste include “making sure we don't carry more inventory than we need” and donating to local food banks still-usable items that for various reasons can no longer be kept on its shelves.
“The de-packaging has always been the most challenging aspect for us in moving forward on our zero food waste goals,” he says. “You simply can't open up every expired food package every day at every one of our stores. It's just not feasible.”
As soon as Agri-Cycle Energy's de-packager was up and running this fall, Blom says, 40 Hannaford supermarkets in the central and northern part of the state immediately reached that zero food waste goal.
Having the ability to introduce organic waste into the digesters, in just the right amount and at just the right time, is part of the unique “edge” that Exeter Agri-Energy has developed at Stonyvale Farm, says Wintle. Its two anaerobic digesters have helped the state's second-largest dairy farm reduce its overhead costs, he says, by converting what had been a problem waste, cow manure, into bio-gas that produces enough heat to replace 700 gallons of heating oil on average and 22,000 kilowatt hours of electricity every day.
On an annual basis, that's enough energy to heat 300 New England homes and enough to power as many as 800 households. Now add to that the byproducts of comfortable animal bedding made from broken-down fibers strained from the digester domes and organic fertilizer from 6 million gallons of effluent pumped from the digesters into storage lagoons for eventual spreading on the farm's 2,500 acres of cropland.
“We've laid the foundation and we're poised for growth,” says Bell. “I feel like over the last three years we've worked out a lot of the kinks that startup companies would have to go through. We've learned what works and what doesn't work and we've put together a very competent capable team that can now go out and execute and drive this conversation. It can help take care of a problem that otherwise wouldn't have a good solution.”
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