Barstow's Anaerobic Digester
The construction of the Farm Powered anaerobic digester at our farm is helping to sustain the farm and the seven generations of our family for the future. Our renewable energy partnership with Vanguard Renewables began in 2015 from our start as Bgreen Energy. With Vanguard Renewables, we became renewable energy innovation leaders and with the fall 2015 expansion our farm’s anaerobic digester we will have one of the largest and most modern anaerobic digestion systems in New England.
The zero-waste, closed-loop Farm Powered anaerobic digester at the farm converts the energy potential in farm and food waste into electricity, heat, and fertilizer. A member of the Cabot Creamery Cooperative, we supply Cabot with milk; Cabot supplies the farm with the organic by-products from butter and milk production; the farm sends power back to the Cabot plant; and the chemical-free fertilizer grows more hay and corn so there is more milk to go back to Cabot for butter production – and that is the closed loop supply chain.
How it Works
We receive more than 14,000 tons of food waste annually from food manufacturers, processors, and users such as Cabot Creamery, Geissler’s Supermarkets, HP Hood, Wind River, Cains, Garelick, Amenico, and McDonalds. The Vanguard Renewables closed-loop Farm Powered Organics to Energy Lifecycle combines that food waste with more than 9000 tons of manure a year from the into the farm in the in the 600,000-gallon anaerobic digestion tank.
The tank operates much like a cow’s stomach with microorganisms in the tank converting sugars, fats, and other compounds into biogas that powers a 300 kW engine annually producing more than 2,100 Mwh of electrical energy, 7,040 MMBTUs of thermal energy, and 30,000 tons of odor-free, organic, liquid fertilizer. The system also sequesters 85% of the greenhouse gases produced on our farm.
With the current expansion just completed, we will be at 800kW. This is in large part a result of the growing success of the Massachusetts’ program to divert food waste from landfills and of an increasing interest from food companies to reduce their carbon footprint.
We now have the ability to produce our own low-cost energy to power the farm and hot water to heat farm buildings and our family homes. The Farm Powered anaerobic digester also provides renewable energy to the surrounding community via the Eversource grid and to the Cabot Creamery/Agri-Mark Cooperative butter plant in West Springfield, Massachusetts.
Massachusetts’ Leadership in Food Waste Reuse
Food is a powerful energy source, yet in the United States, most of the excess food ends up in landfills with harmful consequences to the community. These landfills, coupled with agricultural waste, emit methane, a greenhouse gas that is more than 20 times worse for the environment than CO2. In the USA, organic waste is the second highest component of landfills, which are the largest source of methane emissions and 30-40 percent of the food supply is wasted. This equals more than 20 pounds of food per person per month. At the farm we waste nothing and we reuse everything in the food supply chain for another purpose.
In October 2014, the Massachusetts Department of Environmental Protection (MADEP) implemented a ban on disposal of commercial organic wastes by businesses and institutions that dispose of one ton or more of these materials per week. Instead of landfilling that waste, the state law now says that the waste must be recycled. Farm-based anaerobic digestion is a way that food waste producers can meet state mandates, contribute to renewable energy production, and help sustain a family farm at the same time.
The ban is part of the state's plan to reduce its waste stream by 80 percent by 2050. According to MADEP data from 2011, Massachusetts disposed of 4.9 million tons of solid waste that year, with food waste making up about 17 percent, or about 830,000 tons.
Massachusetts isn't the only state to try to aggressively curb food waste. In the northeast, Vermont and Connecticut along with New York City have similar bans.
Barstow's Anaerobic Digester Fast Facts
- 6-10 million gallons liquid organic fertilizer
- Reduced energy cost
- Free heat
- Odor reduction
- Increased corn and hay crop yields
- Reduction in chemical fertilizers
- Enhanced nutrient management plan
- Built 2013
- 600,000 gallon capacity
- Operated by Casella Organics under contract from Vanguard Renewables
Annual Digester Input:
- 9,125 tons of manure
- 14,000 tons of food waste coming mainly from food processors, supermarkets, and large commercial feeders.
Annual Digester Output:
- Powers a 300kW engine – expanding to 800kW by June 2016
- Produces 285 kW of electricity per hour/2,200 MWh of renewable energy/year
- Removes greenhouse gases equivalent to 3 cars per cow – or 85% of all the methane on the farm
- Produces 30,000 tons of digestate organic liquid fertilizer replacing chemical fertilizers and increasing yields
- Provides energy to the Eversource grid and Cabot Creamery/Agri-Mark Cooperative