Alberta regulators approved TransAlta Corp.'s plans to convert two large coal-fired power plants to operate on natural gas.
In separate decisions Dec. 21, 2018, the Alberta Utilities Commission, or AUC, approved TransAlta's proposals to convert its two-unit Keephills plant and four operating units at its Sundance plant to run on natural gas. In each case, the commission found the conversions would reduce the plants' overall carbon emissions intensity by 45%.
TransAlta has been preparing for the fuel switch for some time to comply with Alberta's order that all coal-fired power plants be shut down by 2030. The company has also invested in a pipeline now under construction to serve its own and potentially other power plants west of Edmonton, Alberta, though the investment in Tidewater Midstream and Infrastructure Ltd. still requires regulatory approval.
The two oldest units at the Sundance plant have already been retired and will not be part of the conversion. The other four, units 3, 4, 5 and 6, began operating between 1976 and 1980 and, according to the AUC order, have a combined generating capacity of 1,693 MW. The conversion work is due to be completed by the end of 2023, extending the operating life of the facility. (AUC Decision 23807-D01-2018)
The two Keephills units slated for conversion are about 35 years old and together can produce a little more than 800 MW. The conversion of these two units is also expected to be finished by the end of 2023. (AUC Decision 23808-D01-2018)
Both plants receive coal from the nearby Highvale Mine, a surface strip coal mine TransAlta owns through a subsidiary.
A third unit at Keephills, Keephills 3, is co-owned by TransAlta and Capital Power Corp. and began operating in 2011. This plant, with an operating capacity of 516 MW, has not been slated for conversion. The companies will receive annual cash payments from the province, produced by a levy on industrial carbon emissions, to operate the plant until 2030.