TransAlta Corp. received approval from the Alberta Electric System Operator to continue mothballing certain coal-fired units at its Sundance power plant.

The company said March 8 that Sundance units 3 and 5 will remain mothballed until Nov. 1, 2021, extended from the previous date of April 1, 2020. TransAlta requested the extension based on its assessment of market prices and conditions.

Sundance has a current operating capacity of 807 MW, according to S&P Global Market Intelligence data. The company has retired units 1 and 2, and continues operating units 4 and 6.

Canada has finalized a plan to phase out most coal-fired electricity by 2030. TransAlta is among the companies seeking to convert coal-fired plants to run on natural gas. The conversion plan includes the four remaining units at Sundance.