Following today’s publication of the National Energy System Operator (NESO) final report into the power outage at North Hyde substation near Hayes in West London in March 2025, we are investigating whether National Grid Electricity Transmission plc breached statutory obligations and licence conditions relating to the condition of their assets at North Hyde which led to the loss of all supplies from North Hyde 275kV substation, impacting thousands of customers, including Heathrow Airport.
Section 9(2) of the Electricity Act 1989 requires National Grid Electricity Transmission to develop and maintain an efficient, co-ordinated and economical system of electricity transmission and facilitate competition in the supply and generation of electricity.
In addition, we are investigating potential breaches of Standard Licence Condition B7(1) of the Transmission Licence which relate to the licensees’ obligation to secure that it has available resources to ensure that it is at all times able to properly and efficiently carry on the transmission business and to comply in all respects with its obligations under the Electricity Transmission licence and the Electricity Act that apply to the transmission business.
The opening of this investigation does not imply that we have made any findings about possible non-compliance by National Grid Electricity Transmission plc.