Earlier on July 14, 2009, the Unit 4 had returned to service after shutting on July 10, 2009. Meanwhile, the services at Unit 5 were closed on July 11, 2009.

The Sundance power facility, with total power generation capacity of 2,071MW, is situated on the south shore of Wabamun Lake, approximately 40 miles (70 km) west of Edmonton, Alberta.

The plant comprises six units, which include units 1 and 2 which became operational in 1970 and 1973 respectively with a capacity of 280MW each, Unit 3 and 5 that commenced operations in 1976 and 1978 respectively with a capacity of 353MW each, Unit 4 that began services in 1977 and Unit 6 in 1980 with a generating capacity of 406MW each.

TransAlta closed operations of Unit 3 at the plant on June 3, 2009, which is expected to resume its services in the third quarter. The company informed that it would close operations at Unit 5 in the third and fourth quarters. All the other units were available for service.

The Sundance facility uses around 9 million tonnes of coal per year, which is mined from the TransAlta’s Highvale Mine.

On its website, TransAlta informed that it has power purchase agreements for Units 1 and 2 of the plant from January 1, 2001 to December 31, 2017, and until December 31, 2020 for the rest of the units. In addition to the above, 44MW from Unit 6 and 53MW from Unit 4 are also added to the Alberta Power Pool, through the PPA Buyers.

TransAlta, owns and operates approximately 8,000MW of generating capacity and sells energy commodities in the US, Canada, Australia and Mexico.