Port Augusta's last coal-fired power station switched off

About 140 workers face an uncertain future after the last of Port Augusta's coal-fired power stations was shut down today.

The Northern power station was taken offline about 10.30am, officially ending more than 60 years of operation.

More than 100 workers will lose their jobs as a result of the closure.

"There is no doubt that today is a sad day for our people, with the cessation of generation signalling the end of an important and proud era for Alinta Energy," Alinta chief Jeff Dimery said.