TransAlta will end operations at Highvale thermal coal mine by the end of 2021 as it switches to natural gas at all of its coal-fired plants in Canada.

The announcement brings with it hundreds of job losses and comes four years earlier than TransAlta originally planned.

After Highvale’s coal mining ends, 40 to 50 people will continue at the site in reclamation work, which is expected to take about 20 years, TransAlta CEO Dawn Farrell said Wednesday on a conference call.

That’s a far cry from the workforce of 1,500 at the mine’s peak. Roy Milne, president of United Steel Workers Local 1595 representing Highvale miners, said workers knew this was coming but the end date has changed several times.

“The membership is already resigned to the fact that those jobs are disappearing,” Milne said.

Highvale near Wabamun Lake, about 70 km west of Edmonton, is one of three surface coal mines owned by TransAlta.

The percentage of power in Alberta generated from coal has fallen from more than 80 per cent in the 1980s to less than one-third now, partly due to rising provincial government prices on carbon that began in 2007.

Some of the laid-off workers will use provincial government programs as a bridge to re-employment or retirement, Milne said, but the closure means workers will have to figure out those next steps sooner than expected.

“There’s been way more stress on the average worker, simply with the uncertainty and the changing target date,” Milne said. “But that’s no different from anybody else that’s been working from home.

“The silver lining for our end is we have a more firm date on where the rest of your life is going to have to go from.”

Workers were notified last week about TransAlta’s announcement, said Don Gray, who has worked at Highvale for a decade.

Gray worked at Whitewood Mine in the same area until it closed in 2010. The 51-year-old then moved over to Highvale and had planned to work there until his retirement. Now he thinks he likely won’t be a part of the mine’s reclamation project.

Some Highvale workers were shocked, he said, at how the timeline to close the site changed so quickly. Some feel misled, he said, after they were expecting to be able to work there for a few years longer.

“Nobody had seen it coming this week from when it was first announced,” he said. “It was supposed to be a slow process and then the timeline just went quick.”

In Wabamun, a village near Highvale, coal mining has been a part of the community’s identity for decades, said Mayor Charlene Smylie. When the transition away from coal mining was first underway, the municipality estimated about one third of residents would be directly affected.

“These are people who have spent most of their lives working at the mine,” Smylie said. “It has been challenging for a lot of our residents and the residents in the area as the jobs have been drying up.”

Coal power profitability is becoming less attractive as the costs of renewable power fall, said Binnu Jeyakumar, the Pembina Institute’s director of clean energy.

“It’s good news for (greenhouse gas) reduction and the health of Albertans to have coal being phased out earlier,” Jeyakumar said.

Jeyakumar cautioned that converted coal plants are unlikely to be as efficient as new natural gas-powered plants, and that emissions from the production and transportation of gas present an ongoing GHG risk.

TransAlta’s announcement was related to the economics of producing power on coal with the carbon tax, Farrell said.

Farrell said TransAlta’s GHG emissions will be under 11.5 million tonnes by the end of 2022, down almost 70 per cent from 2005. She added the company has cut 32 million tonnes per year across its global operations since 2005.

TransAlta said it will stop burning coal in its Keephills Unit 1 and Sundance Unit 4 plants, which will operate at lower capacity with natural gas, while it evaluates full conversion projects.

The company will still produce power from coal at its Centralia facility in Washington state, which has a transition agreement allowing it to burn coal until its end of life in 2025, Farrell said.

TransAlta also owns a 50 per cent stake in the Sheerness power plant in eastern Alberta, which is operated by American firm Heartland Generation Ltd., and continues to burn coal although it has some dual-fuel capabilities.