Information about the 9 August power cut and the ESO

On this page, you’ll find information relating to the power cut in Great Britain on 9 August 2019 and a link to materials to help you understand the energy system and role of the ESO.

Ofgem and E3C reports

Friday 3 January 2020: Industry regulator Ofgem and the Energy Emergencies Executive Committee (E3C) have published their reports into the power outages on Friday 9 August 2019.

Read Ofgem's report

Read E3C's report

Watch and read our response to the reports via the links below.

Read our media statement on the report

ESO final technical report

This is our final technical report into the power outages on Friday 9 August.

Download final technical report

Download appendices


ESO interim technical report

This is our interim technical report into the power outages on Friday 9 August.

Download interim technical report

We have made some minor updates to the ESO’s interim technical report submitted to Ofgem on 16 August to correct small typos and provide further clarity.

Page 5: removed reference to Ofgem’s letter in appendices. Deleted 3 references to “your” and “you think”.

Page 14: added text to explain what the “three speed signals” at Little Barford refers to “[it] resulted in the governor protection control system operating to shut down the steam turbine.”

Page 15: the data on secondary frequency holdings that was included in table 4 should have also been included in Table 3. This is now added in square brackets.

Pages 15 and 18: rounding error in table totals corrected - 1,023 should have read 1,022MW. 


Events timeline

Here is a timeline of the events of Friday 9 August 2019.

Infographic showing power cut sequence of events

Enlarge infographic


Media statements relating to the power cut

These are the media statements issued by National Grid ESO in response to the power cuts in Great Britain on 9 August 2019.

Publication of final technical report - 9 September

Ofgem investigation - 20 August

Submission of interim report to Ofgem - 16 August

Power Cut Statement on Frequency - 13 August

Power Cut Statement - 10 August, 7.30pm

Power Cut Statement - 10 August, 8.30am

Power Cut Statement - 9 August, 8pm

Power Cut Statement - 9 August, 6.30pm

Ofgem’s response to the incident

Here you can read Ofgem’s response to the power failure.

Read Ofgem's response


Energy Emergencies Executive Committee response to the incident

The Energy Emergencies Executive Committee (E3C) has been convened by the Secretary of State for BEIS. E3C is conducting a review of the incident – here is what they have said.

Visit GOV.UK website