Alberta Sundance power station

From Global Energy Monitor

Alberta Sundance is a power station owned and operated by TransAlta in Alberta, Canada.


The undated satellite photo below shows the plant, located 70 kilometers west of Edmonton, Alberta on the south shore of Wabamun Lake.

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The facility is the largest coal-fired electrical generating facility in western Canada, with a total of six generating units:[1]

Retirement and Conversion

In February 2011, TransAlta said it will be closing operations at two of the Sundance coal-fired units because repairs would be too costly. The Sundance 1 and 2 units have been down since December 2010. The units comprise 560 MW of the 2,126 MW Sundance power plant, which operates as a baseload facility for the Alberta electricity system.[2]

The closing of the units could cost consumers more than $200 million in unrealized refunds through Alberta’s Balancing Pool. The agency that oversees power purchase agreements would have to pay that amount to TransAlta as net book value of the plants and to TC Energy as partial payment on the remainder of its contract. TC Energy holds the Sundance units' power purchase agreement and expects reimbursement.[2]

In 2011 TransAlta brought units 1-2 back online because it was demanded under the company’s PPA agreement with TC Energy.[3]

In April 2017 TransAlta said it plans to retire Sundance Units 1-2 effective January 1, 2018, but the utility is seeking approval to have unit 2 on reserve between 2019 and 2021. Additionally, TransAlta plans conversion of Sundance Units 3 to 6 from coal-fired generation to gas-fired generation in the 2021 to 2023 timeframe, for use until the mid-2030s.[4]

In December 2017 TransAlta announced that Unit 3 and Unit 6 would be mothballed until 2020 due to low demand for electricity. The two units then mothballed were actually Unit 3 and Unit 5.[5]

TransAlta retired Sundance Unit 1 effective January 1, 2018, and mothballed Sundance Unit 2 effective January 1, 2018, for a period of up to 2 years.[6]

An October 31, 2018 TransAlta press release states that in the third quarter of 2018 the company "Retired the previously mothballed Sundance Unit 2 due to its relatively short useful life, small size relative to other units, and the capital required to return the unit to service."[7]

In March 2019 TransAlta received approval from the Alberta Electric System Operator to continue mothballing Unit 3 and Unit 5 until November 2021, an extension of 18 months.[8]

In May 2020 TransAlta's CEO Dawn Farrell stated on a quarterly earnings call with investors that Unit 6 would be converted to gas in 2020.[9] The conversion of Unit 6 to gas was completed in February of 2021.[10]

In July 2020 TransAlta officially retired the plant's mothballed Unit 3.[11]

In November 2020, reported that TransAlta will stop using coal before January 1, 2022, converting Unit 4 to burn only natural gas before the announced date. It will also end operation at the Highvale coal mine before the end of 2021.[12] When Unit 4 stops burning coal, its maximum output will fall from 406 MW to 113 MW.[13]

The currently mothballed Sundance Unit 5 is undergoing conversion to run solely on gas. When the conversion is complete, the unit will have a maximum output of 730 MW. The conversion is expected to cost approximately $760 million and be operational by 2023.[14] On TransAlta's Q3 2021 earnings call the company's Chief Financial Officer stated that the repowering of Unit 5 had been suspended and that Unit 4 would be retired in early 2022.[15] According to TransAlta President John Kousinioris, Unit 4 was retired in early 2022.[16]

Capacity upgrades

A 53-megawatt uprate to Sundance 5 was completed in 2009 at a cost of $75 million. Additionally, a 44-megawatt upgrade was completed on Sundance 6 in 2001 and a 53-megawatt uprate on Sundance 4 in 2007. In May 2015, TransAlta completed a 15-megawatt uprate on Sundance 3.[17]

Coal supply

TransAlta's Highvale coal mine supplies Sundance with coal.[18] Transalta will end operation at the Highvale Coal Mine at the end of 2021.[12]

Plant Data

  • Owner: TransAlta Centralia Generation LLC
  • Parent Company: TransAlta
  • Plant Nameplate Capacity: 2,133 MW
  • Location: Wabamun, AB
  • Coordinates: 53.5072, -114.5567
  • Gross generating capacity (operating):
    • Unit 6: Gas-fired steam turbine[13], 401 MW[19] (start-up in 1980, converted from coal in 2021)
  • Gross generating capacity (mothballed):
    • Unit 4: Gas-fired steam turbine[13], 113 MW[19] (start-up unknown)
    • Unit 5: Coal-fired, 433 MW (start-up in 1976)
  • Gross generating capacity (retired): 1362 MW
    • Unit 1: Coal-fired, 280 MW (start-up in 1970, retired in 2018)
    • Unit 2: Coal-fired, 280 MW (start-up in 1970, retired in 2018)
    • Unit 3: Coal-fired, 380 MW (start-up in 1976, retired in 2020)
    • Unit 4: Coal-fired, 433 MW (start-up in 1976, retired in 2022)
    • Unit 6: Coal-fired, 422 MW (start-up in 1980, converted to gas in 2021)
  • Gross generating capacity (cancelled):
    • Unit 5: Gas-fired combined cycle[20], 730 MW[14] (start-up in 1976)
    • Unit 7: Gas-fired combined cycle, 856 MW (start-up year not found, cancelled in 2020)[21][22]
  • Coal Consumption:
  • Coal Source: TransAlta's Highvale coal mine
  • Number of Employees:

Articles and Resources


  1. "Sundance" TransAlta Company Website, accessed April 30, 2010.
  2. 2.0 2.1 "TransAlta issues notice of termination for Sundance units" Power-Gen, Feb. 10, 2011.
  3. "Economics lead to early coal shutdowns, improved possibilities for health and jobs," Pembina Institute, April 20, 2017
  4. "TransAlta Board Approves Plan for Accelerating Transition to Clean Power in Alberta," TransAlta, Apr 19, 2017
  5. TransAlta Announces Accelerated Transition to Clean Energy, TransAlta, Dec. 6, 2017
  6. "Status of Sundance Unit 1 (SD1) and Sundance Unit 2 (SD2) effective January 1, 2018," AESO, Jan 1, 2018
  7. "TransAlta Reports Third Quarter 2018 Results," PR Newswire, Oct 31, 2018
  8. TransAlta to extend mothballing of Sundance coal-fired units, S&P Platts Global, Mar. 11, 2019
  9. TransAlta Corp (TAC) Q1 2020 Earnings Call Transcript, Motley Fool, May 12, 2020
  10. Amanda Stevenson, TransAlta completes first of three coal-to-gas conversions; company aims to be off coal entirely by 2022, Calgary Herald, Feb. 02, 2021
  11. Maryam Adeeb, TransAlta to retire mothballed Sundance coal unit in Alberta, S&P Platts Global, Jul. 23, 2020
  12. 12.0 12.1 "TransAlta announces plan to stop mining coal at Highvale, stop using coal in Canada", November 4, 2020
  13. 13.0 13.1 13.2 TRANSALTA CORPORATION Third Quarter Report for 2020, TransAlta, 2020
  14. 14.0 14.1 TransAlta Advances its Clean Energy Investment Plan, TransAlta, Oct. 30, 2019
  15. Q3 2021 Earnings Call, TransAlta Corporation, Nov. 9, 2021
  16. TransAlta Corporation (TAC) CEO John Kousinioris on Q1 2022 Earnings Call Transcript, Seeking Alpha, May 6, 2022
  17. Sundance, Transalta, accessed June 2020
  18. "Highvale" TransAlta Mine Page, accessed May 5, 2010.
  19. 19.0 19.1 Sundance, TransAlta, accessed Sep 10, 2021
  20. Sundance Power Plant Repowering Decision 25239-D01-2020, Alberta Utilities Commission, Apr 8, 2020
  21. Sundance 7 Gas-Fired Power Plant, Alberta Major Projects, accessed Sep 9, 2021
  22. TransAlta postpones Sundance 7 gas-fired power plant into next decade, Calgary Herald, Oct 30, 2015

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