Coyote has operated at about 50% capacity since late December 2014. The plant was totally idled for a couple of weeks following a December 4 mechanical failure. One unit was placed back in operation before the end of last year.

Otter Tail spokeswoman Cris Oehler said in early July that Coyote should be cranking out electricity at full capacity again sometime this summer after repairs are completed.

Dakota Westmoreland’s nearby Beulah surface mine normally supplies about 2.5 million tons of lignite coal annually to the power plant. Since December, Dakota Westmoreland has adjusted the mine’s production to meet the lower demand for fuel. The mine produced 572,000 tons of coal in the first quarter of 2015 compared to nearly 2.8 million tons in 2014, according to the federal Mine Safety and Health Administration.

Meanwhile, Hoot Lake should resume running summer as well, Oehler said, after the plant’s two units, in operation since 1959 and 1964, respectively, were temporarily idled for economic reasons earlier this year.

Power prices in the Midcontinent Independent System Operator, a regional grid operator, are expected to be sufficiently high this summer to allow for Hoot Lake’s restart, she said. Hoot Lake, which burns subbituminous coal, had not yet returned to service as of early July, however.

Otter Tail invested in pollution controls to enable Hoot Lake to comply with the federal Environmental Protection Agency’s new Mercury and Air Toxics Standards (MATS) rule that took effect in mid-April. The plant currently will retire in 2020. At this time, Otter Tail has not decided to extend Hoot Lake’s life despite the Supreme Court’s June 29 ruling that remanded MATS back to the U.S. Circuit Court of Appeals in Washington, D.C., for further review.

Otter Tail’s largest plant, the 475-megawatt Big Stone station near Big Stone City, South Dakota, is expected to continue operating indefinitely. It also burns subbituminous coal.