Operator RWE hopes to have unit 9 of Tilbury power station in the UK back in service on 20 August, and unit 10 on 27 August. Both units were taken off line following the 27 February fire at the station, which had just been converted to 100% biomass. The fuel hoppers have been extensively refitted. Unit 8, the least affected by the fire, began exporting power to the grid again on 21 June.

RWE has concluded that there was no single event that caused the fire. “A number of relatively minor events that, taken in isolation would not have escalated, combined to cause the fire, which developed from a localised smouldering incident. When wood pellets in neighbouring hoppers were moved, significant air drafts were created and, despite fire suppressant foam having been used to cap the affected areas, it is likely that the increased levels of oxygen caused the ignition of the smouldering dust. Although it has not been possible to definitively identify the mechanism for the escalation, this is considered to be the most likely cause.”

To ensure the safety of the power station as it returns to service, a number of significant changes and improvements have been implemented alongside the repairs.

“The conversion of Tilbury power station created the world’s largest dedicated biomass plant”, says RWE, and, “as the first of its kind, it was likely to expose new challenges and require innovative solutions.” The company says it will “be sharing all key findings with the wider industry in due course.”