Ofgem has opened an enforcement investigation into National Grid Electricity Transmission (NGET) following the publication of a report by NESO into the fire at North Hyde substation on 20 March, which caused a shutdown at Heathrow Airport.
Ofgem said that the report established that the root cause of the fire was “a preventable, technical fault”.
The regulator has also today confirmed that we will commission an independent audit into NGET’s critical assets and their status, to satisfy Ofgem on whether the failings identified in NESO’s report into North Hyde were one-off in nature, or more systemic across the National Grid estate.
Ofgem said it also intends to discuss with the Civil Aviation Authority (CAA) what lessons can be learnt from the North Hyde incident for the wider resilience of the transport system, and to work with DESNZ on NESO’s recommendations relating to the wider resilience of the energy system.
Akshay Kaul, Director General for Infrastructure at Ofgem, said:  “The North Hyde substation fire resulted in global disruption, impacted thousands of local customers, and highlighted the importance of investment in our energy infrastructure.
“As a result of the report’s findings, we have opened an investigation into National Grid Electricity Transmission (NGET). We have also commissioned an independent audit of their most critical assets.
“Ofgem will also further examine the incident and its causes and take further action as appropriate.
“We expect energy companies to properly maintain their equipment and networks to prevent events like this happening. Where there is evidence that they have not, we will take action and hold companies fully to account.  
Other recommendations in the NESO report, commissioned by the Department for Energy and Net Zero (DESNZ) and Ofgem, include revising Critical National Infrastructure policies.
The NESO report said “there is currently no explicit cross-sector requirement on CNI operators to ensure CNI resilience to power disruption, or to set standards of energy resilience”. Electricity system and network operators are prohibited through their licence conditions from discriminating between customers, “which means that a CNI operator is not treated any differently in terms of connection, service, or restoration from any other domestic or commercial customer”. What is more, “energy network operators are not aware whether customers connected to their networks are classified as CNI”.