The longest-running and world's only operating commercial carbon capture facility at a coal-fired power plant struggled with mechanical failures in 2021 that idled the equipment at Saskatchewan Power Corp.'s Boundary Dam plant for weeks at a time.

Joel Cherry, a spokesman for the utility based in Regina, Saskatchewan, said Jan. 5 that the company has been working hard to improve the plant's reliability. SaskPower, the name under which the state-owned power company operates, is conducting an "in-depth analysis" to better manage the plant's operational risks going forward, Cherry said.

The seven-year-old facility's carbon capture rate in 2021 was less than 37% of the official target of 90%. In all, the plant's Unit 3 carbon capture equipment prevented 442,126 tonnes of carbon from being spewed into the atmosphere over the past 12 months. That is less than half of the 1 million tonnes the Boundary Dam Power Station is capable of catching and processing annually for enhanced oil recovery in nearby production fields.

SaskPower installed the $1.5 billion technology, along with other retrofits on its 672-MW coal-fired power plant, in hopes of extending its life for another 30 years. Undeterred by financing and technical challenges, several fossil fuel-heavy U.S. states are pushing for similar projects at aging coal plants to keep them running.

Critics of the Boundary Dam project said the carbon capture facility has never performed as expected. SaskPower monthly reports going back to early 2020 showed frequent, mostly brief outages due to issues like "wet coal," "plugging," "issues in the powerhouse," "trip," "water cooling issues" and other technical hiccups. Unexpected outages of the power plant itself also affected production at the carbon capture facility.

"Boundary Dam 3 has failed to deliver the emissions reductions we were promised, and the unit has been plagued with breakdowns and shutdowns since it began operating," Emily Eaton, a professor of geography and environmental studies at the University of Regina, wrote in an email. "The technology is not working. We cannot afford to base our climate change emissions reduction strategies on a technology that can't deliver the results we need to maintain a safe future."

According to Eaton's calculations, the facility has captured well below 65% of carbon emissions from the 62-year-old coal plant since it began operating in 2014.

A 2015 study showed that the Canadian province could have benefitted financially from shutting down the aging Boundary Dam plant and investing in wind and other low-carbon energy resources. Three years later, SaskPower scrapped plans for adding carbon capture technology to two more units at its coal plant, citing low natural gas prices.

2021 an 'anomaly'

SaskPower noted that its carbon capture facility, a few miles north of the North Dakota border, captured a near-record 729,187 tons of carbon in 2020 and expects to reach that level again.

Following a planned maintenance outage lasting several weeks in June and July of 2021, a component in a large compressor failed shortly after the facility started back up, causing "pretty significant damage," Cherry said.

"We were able to resolve that issue but later had a separate issue with the cooler on the compressor as well," Cherry added. "We had three pretty significant events in a pretty rapid succession, so the year was an anomaly."

Although the Boundary Dam plant is capable of capturing up to 1 million tonnes of carbon emissions, SaskPower's actual carbon capture targets today are lower than what the utility originally promised. That is because the utility's contracts with oilfield operators that demand less, Cherry noted.

"Just because it's capable of that doesn't mean it makes sense operationally to run the facility to max capacity," Cherry said. "Our actual capture target rate is actually between 75% and 80%."