Great River Energy’s (GRE’s) Spiritwood Station began commercial operation on Nov. 1.
The plant—located about 10 miles east of Jamestown, N.D.—is a combined-heat-and-power plant that can generate up to 99 MW of electricity, depending on the amount of steam being supplied to its partner facilities. The station is expected to be about 60% efficient while supplying steam to the Cargill Malt plant, and Dakota Spirit AgEnergy—scheduled to open in 2015—for use in their production processes. By contrast, the average coal-fired plant in the U.S. operates at about 34% efficiency, according to the Energy Information Administration.
“[Spiritwood Station] demonstrates that coal is fertile ground for innovation. The benefits we have seen in North Dakota can—and should—be replicated almost anywhere in the world,” said David Saggau, president and CEO of GRE.
Spiritwood is fueled by lignite and expects to use about 610,000 tons per year. The fuel will be dried and refined at GRE’s Coal Creek Station using the company’s patented DryFining Fuel Enhancement Process discussed in the November issue of POWER. The process uses waste heat from the Coal Creek plant to reduce moisture in the fuel, giving a higher BTU value per pound, and removes higher density products—which contain more sulfur and mercury—thereby reducing emissions. DryFining also lowers transportation and maintenance costs. Once processed, the lignite will be shipped to Spiritwood in enclosed rail cars to prevent moisture from re-entering the coal.
The plant utilizes state-of-the-art emissions-control technologies, including a circulating fluidized bed boiler, selective non-catalytic reduction system, a spray dryer absorber, and baghouse. These controls make it one of the cleanest coal-based power plants in the world. The plant has two back-up natural gas–fired boilers to supply process steam if the main boiler is offline for maintenance.
“From the fuel used to the boiler design to the air quality control system, every element of this project has been crafted to be as efficient as possible,” GRE Generation Vice President Rick Lancaster said.
—Aaron Larson, associate editor (@AaronL_Power, @POWERmagazine)