North Carolina’s largest swine waste-to-energy system is operating at full capacity turning out electricity and by-products such as fertilizer at the Storms Hog Farm near Bladenboro. The 600kW facility, in nearly constant operation since October 2013, sustained near peak output for the last three months.
Using an anaerobic digester developed by DVO, Inc., the facility virtually eliminates odor, pathogens such as e-coli and salmonella, and allows for removal of phosphorus and ammonia nitrogen for use in fertilizers.
“When I started this,” said Jeff Smerko, managing principal of AgPower Partners, “you’d ride up to one of these farms and you could smell it with the windows rolled up and the air conditioning on. When you opened your door you’d get punched in the face with it. The odor now is virtually gone at the Storms farm.”
The concept for the project evolved from a grant for four swine farm renewable energy pilot projects administered by the NC Department of Energy. Sam Ravenel, co-founder of Withers & Ravenel consulting engineers, and Dr. Garth Boyd, Senior Partner of The Prasino Group. applied for a grant in May of 2010.
They won a $500,000 grant, which left $300,000 net after taxes, including $34,500 the state got back (the rest went to the U.S. Treasury). The money was part of the $175 million the state received from The American Recovery and Reinvestment Act (AARA).
Boyd formed AgPower Partners LLC, (APP) with energy and real estate developer, Smerko, to develop the Storms project. APP turned to DVO Inc. for its patented Two-Stage Mixed Plug FlowTManaerobic digester, and to Martin Machinery/GenTec for its biogas engine/generator turn-key services. APP facilitated construction and term debt financing through Cape Fear Farm Credit for the project owner and operator, William R. Storms, who is also the farm owner and operator.
The system uses an “enhanced” animal waste extraction and collection system using scrapers instead of flush water to remove manure from the houses, considerably reducing the environmental impacts of current lagoon and spray field systems.
In a news release about the project, Jonathan Gross, Charlotte-based partner at CohnReznick LLP, which is providing accounting services for the project said, “The North Carolina Senate Bill 3, mandating that utilities have swine generated electricity as a small part of their total portfolio, enabled farmers like Mr. Storms to try something that would have been untenable without the incentive. The team that developed Storms Hog Power has overcome bureaucratic and modeling challenges to make the project bankable. The end result is a model that makes sense, that works – and that can be repeated.”
(Who are the power players in the deal? The list.)
Manure collected daily from nearly 30,000 hogs, formerly treated in open air lagoons, is mixed with a small percentage of other off-site agricultural wastes which were previously either land applied or destined for a landfill. It is biologically decomposed in an oxygen-free, 1.2 million gallon reinforced concrete vessel.
The bacteria in the digester metabolically break down the organic waste streams and generate energy-rich biogas, while destroying nearly all of the pathogens and odor. The biogas is combusted in an engine/generator, sending enough clean renewable electricity to the local utility to offset the electricity consumption of nearly 300 average size homes in the area.
Doug Van Ornum of DVO tells WRAL TechWire the digesters are not inexpensive, but the price is scalable, ranging from $1.5 million for a single unit to $10 million for a large farm and considerably more for those used by municipal waste management systems.
He points out, however, “That it doesn’t matter what it costs if it doesn’t make financial sense.”
Van Ornum notes that in addition to providing clean, renewable energy, the system has considerable other beneficial effects, such as greatly reducing green house gasses such as methane. “The digester converts them to electricity, removing 90 percent of greenhouse gasses from manure handling.”
He adds that unlike wind and solar renewable energy, this system cranks out electricity reliably 24/7.
Right now, the project would not be financially feasible without the state grant and the higher rate utilities have to pay for the electricity generated by the project. Smerko notes that it’s similar to the development of efficient solar energy systems. Once a technology is sufficiently effective, the subsidies become no longer necessary.