Learning lessons from the August blackout

Learning lessons from the August blackout

  • 11 September 2019 10:20
  • Energy

A few weeks ago Britain was plunged into its first major blackout in more than ten years, resulting in widespread disruption just as a Friday evening rush hour was getting under way.

The incident has triggered a number of investigations in to what went wrong, and has prompted renewed calls for the renationalisation of the system operator, National Grid, a step which the new energy minister Kwasi Kwarteng has said he is considering.

So what lessons should we be drawing from the blackouts, based on the information we have so far?

The final technical report into the blackout has just been published by National Grid, and it identifies a sequence of events beginning with a lightning strike on part of the transmission network that triggered the loss of power from two major generators, as well as some small-scale renewables.

This loss of generation exceeded available reserves, and ultimately led to over 1 million customers losing power temporarily across the country. Although power was restored to most within 45 minutes, there was considerable disruption for several hours, principally on rail networks in the south east of England. There was also a sustained loss of power at a hospital in Ipswich and at Newcastle Airport.

Blame game

While National Grid has attracted some justifiable criticism in the past for the generous profits it makes, as well as for staffing cuts and its general approach to industrial relations, in this instance (if the technical evidence is accurate) it is not clear that Grid is the primary culprit.

Much of the disruption on the rail network, for example, was not the result of a loss of power (most parts of rail system were not disconnected) but was caused by faults with a series of new Thameslink trains.

The temporary fluctuation in power frequency caused them to shut down, and they then could not be restarted by their drivers in many cases. Overcrowded transport infrastructure around London was simply unable to cope with the cascade of delays this unleashed, and the regional rail system ground to a halt for several hours.

Similarly, the problems at Ipswich Hospital appear to have been due to faults with the hospital’s own electrical systems and not because of a loss power.

What all of this suggests is that a key lesson from the August 9th events may be how generally untested and unprepared parts of our public infrastructure are for a crisis event.

This is cause for concern given current levels of political and economic instability, as well as the longer term impact that a changing climate may have on much of our critical infrastructure.

The blackouts could then be a timely opportunity for us to examine the resilience of that infrastructure and ensure that sufficient resources, adequate staffing, and clear procedures are put in place to cope with the unexpected.

Nick Kardahji

Nick Kardahji


  • Interesting blog. Do we know what the frequency dropped down to? If I remember my power station days correctly, I think at about 48.5 Hz plant disconnections start happening. As an aside, my power station days were at Little Barford when there were two coal burning stations.  


    Paul Fenech

    11 September 2019 12:57

  • Dear Paul

    Thank you for your comment. According to the final technical report from Grid, the frequency bottomed out at 48.8Hz, which is when the Low Frequency Demand Disconnection system was activated.

    The full technical report is available here – https://www.nationalgrideso.com/document/152346/download.

    Nick Kardahji

    19 September 2019 09:09

You cannot currently add comments, please log in to add a comment.