It came as drone footage has revealed the scale of destruction caused by the explosion.
The fire centred on an anaerobic digestion facility, located in Yarnton near Oxford, which was struck by lightning. The hit resulted in a biogas tank exploding, plant operators Severn Trent Green Power said.
On Tuesday morning three plastic tents covering the digester tanks were seen to be still smouldering.
Anaerobic digestion processes plant materials, known as biomass, into gas to be used for heating and power; the resultant gas is called methane or biogas and is created by bacteria which digest biomass and produce methane as a by-product.
A Severn Trent Green Power spokesperson said: “We’d like to thank the emergency services for their work overnight to contain and lead the incident at Cassington, where our plant was struck by lightning.
“Keeping our teams and the local community safe has been of paramount importance and we are relieved that no one has been hurt.
“We will continue to work with the emergency services who are still on site as we assess the damage and while the fire is out, we urge people not to come to the site today.”
Emergency services attended the incident, with 40 firefighters reported to be at the scene. South Central Ambulance Service confirmed paramedics attended - but a spokesperson said there were no reports of casualties.
The explosion followed heavy showers accompanied by lightning strikes with the region under a yellow weather warning issued by the Met Office.
Jack Frowde, 34, from Oxford, who works at Oxford University, said: “I was sitting in my kitchen when the whole room lit up with a brilliant white light, then followed by a huge crack which sounded like really heavy thunder.
“I looked out of the kitchen window and it was as if the sky was pulsating orange. I ran to the back to capture the orange glow as it faded after about 20 seconds.”
Mahmet Ciftci posted on X, formerly Twitter: “Just saw something here in Kidlington that looked like an explosion in the distance. We heard a rumble like thunder and saw flames in the distance. The horizon went orange for a while.”
As many as 40 firefighters rushed to be at the scene. South Central Ambulance Service confirmed paramedics attended - but a spokesperson confirmed there were no reports of casualties.