An Indiana utility is delaying the retirement of two coal plants citing the uncertainty caused by a U.S. Commerce Department trade probe into solar imports, as the fallout from the probe continues to spread through the power sector.

NiSource Inc. said Wednesday it was pushing the planned retirement of the last two coal units at its Schahfer Generating Station to end of 2025 from 2023 because of delays related to the ongoing investigation on solar tariffs.

“The U.S. Commerce department circumvention investigation related to the import of solar components from select geographies has brought uncertainty and delays to the solar panel market,” the Merrillville, Indiana-based company said in a statement, adding the probe was delaying its planned solar projects as well. “The company anticipates that most solar projects originally scheduled for completion in 2022 and 2023 will experience delays of approximately 6 to 18 months.”

Uncertainty surrounding the Commerce Department’s probe into whether Chinese solar-panel manufactures are circumventing tariffs is already causing projects to be canceled or delayed, with domestic installations expected to be slashed by 46% this year and next, according the Solar Energy Industries Association.