Working together to meet future energy needs
An overview of the power plant and transmission projects
To ensure abundant, reliable, and affordable energy in the face of increasing demand, five power companies serving more than a million people have proposed building a new electric generating plant in South Dakota. An associated transmission project calls for upgrading and adding to the transmission grid in order to deliver the power generated by the proposed plant.
Project participants include:
- Otter Tail Power Company as the lead developer, Fergus Falls, Minn.
- Central Minnesota Municipal Power Agency, Blue Earth, Minn.
- Heartland Consumers Power District, Madison, S.D.
- Missouri River Energy Services, Sioux Falls, S.D.
- Montana-Dakota Utilities Co., Bismarck, N.D.
While these utilities represent two different types of company structures—investor-owned and cooperative—they share a responsibility to deliver baseload energy to their members and customers, along with a commitment to deliver that energy in the most efficient, cost effective, and environmentally responsible way possible.
A need for more electricity that can't wait
More people in our region are using more energy than ever before. Electrical consumption is growing at about 2.5% per year and forecasts call for that trend to continue. In fact, the demand for energy is expected to increase 15% over the next decade. Yet, the last significant power plant construction in our region was completed in the mid-1980s.
The Mid-Continent Area Power Pool (MAPP) has been one of the nation's most reliable systems, but studies indicate we could experience an energy shortfall as early as 2007. To avoid a situation where demand outpaces production, additional capacity to generate baseload power will be needed. Because it takes four to six years to plan, site and build a baseload generating plant, we need to act now to prevent a supply problem in the near future.
What is Big Stone II?
Big Stone II has two components—increased power generation and increased energy transmission.
Generation project
The proposed 630-megawatt power plant is designed to optimize existing and new construction to achieve the greatest efficiency with the fewest emissions. It will be built next to the existing Big Stone I plant near Milbank, S.D., to take advantage of infrastructure already in place, including railway access, coal-handling facilities, and water pumping equipment.
With the addition of Big Stone II, the generating capacity of the power station will more than double, while the amount of emissions emitted into the atmosphere will not increase from current levels. In fact, the two plants combined will emit the same amount or less SO2, NOx and mercury than the existing plant does today.
Big Stone II will use a proven technology for a plant this size—a "supercritical" pulverized coal-fired boiler that represents the most efficient baseload generating technology currently commercially available. In addition, supercritical conditions achieve CO2 emissions 20% less than the regional average of existing coal-fired units.
Participants also have decided to install a single, highly advanced wet scrubber to serve both Big Stone I and II, which will limit SO2 emissions from both plants to approximately one-seventh of the current levels from Big Stone I.
Transmission project
The proposed transmission project will deliver the electricity generated at the Big Stone II plant, along with future renewable and other energy, to regional customers. The project includes upgrades and new construction of power lines and substations, with two corridor alternatives currently being considered.
Consideration of regional studies has been included in the decision-making process for Big Stone transmission lines, resulting in a plan that will improve the reliability of regional transmission system from western North Dakota to central Minnesota .
Also, participants decided to increase the voltage of one of the proposed lines so that it has the ability to transfer more than 800 megawatts above Big Stone's needs, making room for renewable forms of energy, such as wind.
By utilizing new technologies in environmental protection equipment, emissions of sulfur dioxide, nitrogen oxides and mercury from the two Big Stone plants will be as clean, or cleaner than they are now with a single plant. And because of our investments, the new plant will emit 18% less carbon dioxide into the atmosphere than existing plants in the region.
Big Stone II will add diversity and reduce single-outage resource risk for each participating utility and its customers.
Planning for an environmentally responsible, energy-balanced future
There are no "perfect" energy solutions when taking into account cost, reliability, and environmental concerns.
Renewable fuels such as wind, water and biomass are vital components of any energy mix, but are either not reliable enough, nor abundant enough, to supply large baseload generation that runs nearly all the time to meet customers' daily needs. Natural gas is reliable, but its cost is much higher than coal, and more volatile. Coal is not without its challenges as well. Decades of improvements in pollution control technology have made today's power plants much cleaner and more efficient, allowing for the capture of many pollutants that had been emitted by earlier generating units. While we support and invest in ongoing research that may one day allow us to burn coal with near zero emissions, we are not yet there.
Everyone wants clean air and a safe environment. Everyone also wants reliable and affordable energy. We believe that Big Stone II, with its supercritical pulverized coal technology—providing greater efficiency and fewer emissions—offers the best solution to meeting all of these requirements.
Renewable energy is playing and will continue to play an important role in helping us produce the energy we need, but it is only part of the solution. We must also have a dependable supply of electricity that is available for use whenever someone wants to turn on the lights or use the kitchen stove.
For each of the participating utilities, Big Stone II represents just one part of a diverse and balanced power supply portfolio that will help our nation achieve energy independence.
Quick facts about Big Stone II:
- Big Stone II has two components: increased power generation and increased energy transmission
- Presently in permitting phase, including public input process, through end of 2006
- Construction begins (pending approval): 2008
- Generating power commercially available: mid-2011 to mid-2012
- Projected cost: generation project, $1.25 billion—joint scrubber an additional $50 million—transmission project up to $255 million
- Local economic impact of $675 million during 4-year construction process
- Will be the largest investment of public and private capital ever made in South Dakota
- Project will serve more than a million people, in five states in the Upper Midwest.
For more information, contact:
Dan Sharp, Manager, Communications . 701-426-3650
Steve Schultz, Manager, External Affairs . 218-770-9111
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