SUMMARY

The conversion of Keephills Unit 3 is the last coal-to-gas switch in the utility's Canadian portfolio [Image: TransAlta]

By Dale Lunan

Canadian power utility TransAlta said December 29 it had completed the last of three planned coal-to-gas conversions at its Wabamun thermal generating complex west of Edmonton.

“The full conversion of Keephills Unit 3 (KH3) from thermal coal to natural gas is a significant milestone for TransAlta in its transition off coal,” CEO John Kousinioris said. “We are pleased to have completed this important step, nine years ahead of the government target.”

The conversion, he said, maintains the current generation capacity of KH3 at 463 MW but reduces CO2 emissions by nearly 50%, to 0.43 mt of CO2-equivalent (mtCO2e)/MWh from about 0.86 mtCO2e/MWh.

The conversion of KH3 represented a C$29mn investment along with a C$48mn investment in gas infrastructure and maintenance projects. Since 2019, TransAlta has invested C$295mn in its coal-to-gas conversion programme, which included the conversion of its Sundance Unit 6 in Q1 2021, Keephills Unit 2 in Q3 2021 and the earlier conversion of Units 1 and 2 at the Sheerness complex northeast of Calgary, in which TransAlta holds a 25% ownership interest.

Overall, the converted units generate nearly 50% fewer COemissions fueled by natural gas compared to coal, TransAlta said, representing a “significant” step towards its target to reduce 60% or 19.7mn mt, of annual greenhouse gas emissions by 2030 over 2015 levels and achieve carbon neutrality by 2050.

With completion of the KH3 conversion, TransAlta has retired 3,794 MW of coal-fired generating capacity since 2018 and converted 1,659 MW of capacity from coal to natural gas. Its last coal-fired facility, Centralia in Washington state, will be retired in 2025.

The utility’s portfolio, which includes operating facilities in Canada, the US and Australia, includes 3,389 MW of thermal generating capacity, 2,191 MW of natural gas, 1,892 MW of wind, 949 MW of hydroelectric and 21.1 MW of solar. It has a 10 MW battery storage system adjacent to its Summerview Wind Farm in southwestern Alberta and is developing another 1,140 MW of energy storage, solar and wind capacity in Canada and the US.


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