The coal-fired power station near Retford in North Nottinghamshire is set to close.
The power station that has been in operation for more than 50 years, will close on 30 September under EDF Energy plans.
150 jobs are now at risk.
The company has said that the decision to close the plant “reflects the challenging market conditions over the last few years and the context of the drive to decarbonise electricity generation.”
Cottam Power plant manager Andy Powell said: “When the power station was built it was designed to operate for 30 years.
“It’s a credit to our people, the engineering and EDF Energy’s investment that it has operated for more than 50 years.
“There has been an aspiration to move away from coal for a long time now and we have prepared thoroughly for the closure.
“We have a highly skilled and experienced workforce and we’re determined to support our people throughout this process.
“Today 158 people working at Cottam are in scope. During 2017 we supported 19 people to move into alternative roles within EDF Energy, and an additional 22 will be transferring into alternative roles over the coming months.
“We are conscious of the need to support a just transition to a low carbon energy system. Our ambition is to close the station safely and responsibly by managing people and the environment properly and continuing to be a good neighbour.”