The Kilroot power station in County Antrim has not shown any signs of fire, according to the Northern Ireland Fire and Rescue Service (NIFRS).
According to the NIFRS, seven appliances responded to the incident on Larne Road in Carrickfergus.
It said that at 08:00 BST on Tuesday, it got a call concerning a possible fire in an air vent silo.
There were no overt evidence of fire, according to continual temperature readings taken by firefighters.
At 10:54 BST, the fire department left the area.