Hog operations of many sizes and in various locations have successfully implemented anaerobic digesters and are reaping financial renewable energy benefits.
A survey by the University of Oklahoma Department of Agricultural Economics of owners of anaerobic digesters on swine operations found that the systems produced methane that generated more than $179,000 worth of electricity each year with an initial capital investment of more than $2 million. Government grants covered about 60% of the initial capital investment. Carbon credits also provided some monetary value, which varies depending on the type of credits.
Here are a few examples of hog operations that have had a positive experience after building an anaerobic digester:
Butler Farms, North Carolina
Butler Farms has been operating a 10-barn swine finishing facility since 1995 with 8,000 hogs. The operation produces about 10,000 gallons of manure daily. Due to neighbor complaints about odor, the farm covered two lagoons in 2008 on four acres, capturing biogas from the lagoons. The captured gas was flared, generating credits from their carbon offset. In 2012, a new anaerobic digestion system was installed and Butler Farms entered a power purchase agreement with their local electrical utility, South River Electric Membership Cooperation (EMC) to sell the renewable energy. At that time, the captured biogas began being used to generate electricity for the operation. In 2017, the farm partnered with South River EMC to develop an on-site microgrid using the farm’s biogas generator and solar array. During a power outage, the microgrid can operate independently and provide power to the farm and surrounding homes, allowing for increased stability for the local electricity supply and the farm operation can give back to the community.
Loyd Ray Farms, North Carolina
Loyd Ray Farms is a feeder-to-finish swine farm with nine barns housing about 8,600 hogs. A waste management system was built in 2011, including a lined and covered anaerobic digester basin. The system also has a lined in-ground aeration basin for treating other waste products and mitigating odors. The anaerobic digester holds about 2.1 million gallons of manure and wastewater. Approximately 400,000 gallons are flushed from barns into the anaerobic digester weekly. Biogas production is estimated to be 50,400 ft/day and generates electricity and the system also has a backup flare when gas production exceeds the microturbine’s capacity. The total cost of the waste management system was $1.2 million, including the electricity-producing components and the environmental system.
Pine Hurst Acres, Pennsylvania
Pine Hurst Acres began operating an anaerobic digester in October 2004, with 4,400 hogs contributing manure to the digester from two barns. The operation has a slotted floor with a deep pit under the floor to handle manure. The biogas generator also has a flare for the excess biogas produced. Pine Hurst Acres currently does not have a power purchase agreement with their local electrical utility.
Read More:
Anaerobic Digesters on Swine Farms: Convert Manure into Energy
