Independent report

Great Britain power system disruption review

Review of the power disruption on 9 August 2019 by the Energy Emergencies Executive Committee (E3C).



On Friday 9 August 2019 a power disruption resulted from the operation of Low Frequency Demand Disconnection relays on the Great Britain power system at about 4:54 pm. It impacted hundreds of thousands of customers, and caused significant secondary impacts in particular to the transport network. Though demand was fully restored within 90 minutes, the secondary impacts continued to be felt for much of the day.

The Secretary of State for Business, Energy and Industrial Strategy commissioned E3C to undertake a comprehensive review of the incident. The review was to identify lessons and recommendations for the prevention and management of future power disruption events. In particular E3C was to:

  • assess direct and secondary impacts of the event across GB electricity networks
  • Identify areas of good practice and where improvements are required for system resilience
  • consider load shedding in regard to essential service customers and prioritisation
  • consider timeliness and content of public communications during the incident
  • make recommendations for essential service resilience to power disruptions

E3C were required to submit a final report to the Secretary of State within 12 weeks, with an interim report within 5 weeks.

E3C is a partnership between government, the regulator, and industry, which ensures a joined up approach to emergency response and recovery.

Published 14 August 2019
Last updated 3 January 2020 + show all updates
  1. Final review report published.

  2. Interim report published.

  3. First published.