Four fire engines and around 25 firefighters were called to a fire at an energy production plant in Coldharbour Lane in Rainham.
A gas turbine inside a shipping container was damaged by fire.
The Brigade was called at 0808 and the fire was under control at 0943. Fire crews from Wennington, Barking and Hornchurch fire stations attended the scene.
The cause of the fire is believed to be accidental and due to an electrical fault.