3 Questions with
During your presentation, you’re going to discuss the Optima-KV project. Can you give us a broad overview of it?
Optima-KV is the first organic recycling system in North Carolina to place renewable natural gas (RNG) into the existing natural gas pipeline. In fact, it is the first natural gas ever to be placed into the pipeline from within North Carolina, from any source; and it happens to be from a renewable resource—swine waste. In addition to this giant first step, it is also the first system to aggregate biogas produced from multiple sources to a single upgrading/refining point. The system consists of a gathering pipe system that collects biogas from the anaerobic digestion of swine manure and wastes from five proximate farms. The resulting RNG has been purchased by Duke Energy under a 15-year offtake agreement, and will be used by Duke Energy to produce renewable electricity through nomination at one or more of their existing combined cycle power plants.
The project is expected to yield about 80,000 MMBtu (dekatherms) per year of renewable RNG, which will generate approximately 11,100 megawatt-hours of electricity annually, enough to power about 880 homes, which is a little over twice the number of homes in Kenansville, North Carolina.
You mention the design is innovative. Can you elaborate a bit?
Optima-KV aggregates the biogas produced by five proximate swine farms near Kenansville, North Carolina in an effort to improve the economics of such waste-to-energy endeavors. Aggregating the biogas, rather than the manure and wastes as has been the conventional thought, means that the nutrient recovery and biosecurity concerns of the participating farmers are properly addressed, while the economics of scale associated with the biogas upgrading and RNG pipeline injection can be accomplished. Manures and wastes generated by the farms’ combined 60,000 animals is directed into a newly constructed anaerobic digester serving each farm. A centralized gas upgrading system uses a pressure swing adsorption process to remove unwanted biogas constituents, such as moisture and carbon dioxide, to refine the biogas to the specifications for pipeline injection—the first natural gas (which happens to be from a renewable source) to come from within the state’s borders.
North Carolina has a unique renewable portfolio standard. What is it, and how does the project benefit?
North Carolina is one of many states in the U.S. with a renewable energy portfolio standard, but the only one with a specific requirement for a portion of the renewable energy requirement dedicated to the derivation of energy from swine farming and poultry farming wastes.
Specifically, the NC REPS requires investor-owned utilities in North Carolina to provide up to 12.5 percent of their energy through renewable energy resources or energy efficiency measures, and Rural Electric Cooperatives and Municipal Electric suppliers are subject to a 10 percent REPS.
The REPS is meant to aide in stewardship of our natural resources, and address the increasing costs of waste disposal, such as the increasing costs of energy inputs to do so, and provide a catalyst for new investment in NC agriculture. While it obviously helps the rural communities through providing a stimulus, promoting economic growth, it is also improving the environment by achieving a superior level of waste treatment, and a reduction in the carbon footprint created by the conventional waste management system.
See Simmons Speak On Tuesday, April 18 (3:30 pm - 5:00 pm )
Biogas Case Studies II: Managing Animal Waste Streams with Anaerobic Digestion
|