BIG STONE II

Five local utilities have signed agreements to build a second electric generating unit on the site of the existing Big Stone Plant near Milbank, South Dakota.

Based on increasing demand and studies that point to a potential energy shortfall, the companies began working together in 2003 to resolve their mutual need for baseload energy.


Studies included:

  • a cost and performance comparison of state-of-the-art coal combustion and emissions technologies in various size ranges;

  • estimates of air emission rates;

  • an evaluation of designs to provide a reliable quantity of cooling water from Big Stone Lake while minimizing impacts and costs.

The result of these efforts was an agreement to develop an electric generating plant that would be:

  • a cost and performance comparison of state-of-the-art coal combustion and emissions technologies in various size ranges;

  • estimates of air emission rates;

  • approximately 500-580 megawatts;

  • coal based;

  • designed with the best available emission control technologies at the time of purchase;

  • available to serve the customers of the investing utilities.

Project Timeline:

NOTE: Plant construction is contingent on approval of all necessary permits, as a result, this is a proposed timeline.

  • Initial announcement - October 2004;

  • Permitting and Public Comment - Early 2005 through spring 2008;

  • Construction begins - Mid-2009;

  • Plant commercially available - Mid 2013.

Project Impact:

  • Big Stone II represents the largest investment of private and public capital ever made in South Dakota;

  • The electricity it produces will flow to customers in Minnesota, North Dakota, South Dakota, Montana, and Iowa;

  • During its four year construction period, the plant would employ an average of 625 construction workers, with a peak workforce of 1,500;

  • Once online, Big Stone II would likely employ 35 to 40 operational workers at the site.

Project Cost:

  • Early cost estimates for the power plant were at about $1 billion, with an additional $200 million for the transmission line project. These costs estimates have increased, however, due to higher costs for construction materials and labor;

  • Other cost factors include market pricing by vendors as well as design changes made by project participants to increase output and improve efficiency;

  • Based on the most recent design refinements, the project including transmission, is expected to cost $1.6 billion;

  • Efforts continue to maximize efficiencies and minimize costs.
Big Stone II project achieves key milestones



Contact Information:

Eastern South Dakota Building and Construction Trades Council
101 S. Fairfax Ave.
Sioux Falls SD 57103

605-335-9611 Office
605-335-5944 Fax

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