Firefighters are investigating the cause of a major blaze at Didcot B power station in Oxfordshire.
At its height, 25 fire engines and about 100 firefighters tackled the blaze at the gas-fired station, which broke out at about 20:00 BST on Sunday.
The station was partially shut down, but Energy Secretary Ed Davey said National Grid had assured him that there was no risk to energy supplies.
The fire was later extinguished and there were no injuries.
Dave Bray, the fire service's incident commander, said: "We have extinguished the fire, although there are hot spots that are remaining within the structure.