Neil Simpson Power Plants

From Global Energy Monitor

Neil Simpson Complex is a 90.0-megawatt (MW) coal-fired power complex operated by South Dakota Electric near Gillette, Wyoming


The facility sits immediately to the south of PacifiCorp's Wyodak Power Plant and Black Hills Corporation's Wygen Station.

Loading map...

Plant Data

  • Owner: South Dakota Electric[1]
  • Parent Company: Black Hills Corporation
  • Plant Nameplate Capacity: 111.7 MW (Megawatts)
  • Units and In-Service Dates: Unit 1: 21.7 MW (1959), Unit 2: 90.0 MW (1995)
  • Location: 13151 Hwy. 51, Gillette, WY 82718
  • GPS Coordinates: 44.285454, -105.383451
  • Technology: Subcritical (Unit 2)
  • Coal type: Sub Bituminous
  • Coal Consumption:
  • Coal Source: Wyodak Mine (Black Hills)[2]
  • Number of Employees:
  • Unit Retirements: Unit 1 retired in 2014.[3]


The 21.7 MW Neil Simpson Power Plant 1 went online in 1959 and was retired in 2014. The 90 MW Neil Simpson II plant went online in 1995.[3]

Emissions Data

  • CO2 Emissions: 939,879 tons (2006)
  • SO2 Emissions: 1,792 tons (2002)
  • SO2 Emissions per MWh: 4.50 lb/MWh
  • NOx Emissions: 1,461 tons (2002)
  • Mercury Emissions:

Death and disease attributable to fine particle pollution from Neil Simpson Power Plant

In 2010, Abt Associates issued a study commissioned by the Clean Air Task Force, a nonprofit research and advocacy organization, quantifying the deaths and other health effects attributable to fine particle pollution from coal-fired power plants.[4] Fine particle pollution consists of a complex mixture of soot, heavy metals, sulfur dioxide, and nitrogen oxides. Among these particles, the most dangerous are those less than 2.5 microns in diameter, which are so tiny that they can evade the lung's natural defenses, enter the bloodstream, and be transported to vital organs. Impacts are especially severe among the elderly, children, and those with respiratory disease. The study found that over 13,000 deaths and tens of thousands of cases of chronic bronchitis, acute bronchitis, asthma, congestive heart failure, acute myocardial infarction, dysrhythmia, ischemic heart disease, chronic lung disease, and pneumonia each year are attributable to fine particle pollution from U.S. coal plant emissions. These deaths and illnesses are major examples of coal's external costs, i.e. uncompensated harms inflicted upon the public at large. Low-income and minority populations are disproportionately impacted as well, due to the tendency of companies to avoid locating power plants upwind of affluent communities. To monetize the health impact of fine particle pollution from each coal plant, Abt assigned a value of $7,300,000 to each 2010 mortality, based on a range of government and private studies. Valuations of illnesses ranged from $52 for an asthma episode to $440,000 for a case of chronic bronchitis.[5]

Table 1: Death and disease attributable to fine particle pollution from Neil Simpson Power Plant

Type of Impact Annual Incidence Valuation
Deaths 1 $8,100,000
Heart attacks 2 $180,000
Asthma attacks 20 $1,000
Hospital admissions 1 $18,000
Chronic bronchitis 1 $310,000
Asthma ER visits 1 <$1,000

Source: "Find Your Risk from Power Plant Pollution," Clean Air Task Force interactive table, accessed February 2011

Citizen groups

Articles and Resources


  1. "Black Hills Corp 2019 Annual Report" blackhillscorp, accessed June 17,2020
  2. "EIA 923 March 2020" EIA 923 2020.
  3. 3.0 3.1 "EIA 860m March 2020", 860m database March 2020.
  4. "The Toll from Coal: An Updated Assessment of Death and Disease from America's Dirtiest Energy Source," Clean Air Task Force, September 2010.
  5. "Technical Support Document for the Powerplant Impact Estimator Software Tool," Prepared for the Clean Air Task Force by Abt Associates, July 2010

Related SourceWatch Articles

External Articles