Published On: November 7, 2022

In this blog post Lord Toby Harris, Chair of the National Preparedness Commission, shares his thoughts on the news that plans to cope with power outages are being “stress tested” across UK government departments as part of Programme Yarrow, and looks at the implications of such outages on contingency planning across various systems, including transport, services and utilities. 

The Guardian newspaper reported on 1st November 2022 that it had seen “official sensitive” documents from within UK government about “Programme Yarrow” – the emergency plans drawn up to cope with a national power failure lasting up to seven days. These plans – originally drawn up in 2021 – pre-date both the war in Ukraine and current fears about power cuts this winter.

The documents describe a “reasonable worst case” scenario where the outage would cause major disruption to communications and transport, as well as to food and water supplies. There have been a series of recent exercises within UK government departments and other agencies to see how the plans might work in practice.

Planning like this is welcome and builds on earlier work to identify the wider effects of such power failures on public services. For example, in May 2017, London Resilience organised a workshop that looked at the consequences of a major power failure using the “Anytown” methodology. A gap analysis was produced from this by the Institute for Risk and Disaster Reduction at University College London.

It would be wrong to regard widespread and prolonged power failures as remote and fanciful possibilities. The Texas power failure in February 2021 provided a dramatic illustration of vulnerability in a modern highly industrialised state (Texas, if a nation, would be the tenth largest economy in the world). It highlighted the following:

  • Failure to invest adequately in the maintenance of critical infrastructure.
  • Reliance on ever more complex and inter-connected systems.
  • Dangers of cascade collapse.

On 5th December 2015, Storm Desmond led the River Lune in the UK to flood. This was described as a “one in a hundred year event” (aren’t they always?) resulting an electrical sub-station serving the city of Lancaster being swamped. More than 60,000 homes and businesses, and at least 100,000 people, were left without electricity for four days. ATM machines went out of action, garages were unable to dispense fuel as their pumps needed electricity to operate, traffic lights stopped working, and the train station had to close. Text messaging, digital radio and the internet ceased to be available and 75 emergency generators had to be brought to Lancaster from as far away as the southwest of England and across from Northern Ireland in order to regain electricity supplies.

However, as the Royal Academy of Engineering pointed out, this was a “comparatively localised area” “manageable in size”, whereas in a much larger area or locality with a much bigger population, such arrangements would not have worked. The Lancaster incident highlighted the inter-connected nature of our critical systems and our reliance on electric power to make them work and society function. But what would happen in the event of a major and more widespread outage, or one that lasted longer?

Some services would of course stop being provided. Schools routinely close if the heating stops working or there is a power cut. How many hospitals will function if their electricity supply is disrupted? Presumably only those with functioning emergency generators and even then, it will depend on staff continuing to come to work. (Incidentally, experience is that because emergency generators are only used in emergencies they often do not work properly or fail quickly – and in any case have to be kept supplied with diesel.)

And some systems would have to be provided with power come what may. Nuclear plants – whether functioning or not – will still need to ensure that the reactor core is cooled. Another critical area is water. All buildings above three storeys and many locations will not be reached without electric pumps; so how long could a supply of fresh water be guaranteed? And for how long would waste water and sewage be removed and treated? If a certain flow is not maintained, sewage tends to solidify. A city or town without fresh water or where wastewater and sewage cannot be removed rapidly becomes uninhabitable.

In a similar vein, how long could communications systems be maintained? Domestic and business landlines require electric power, as the days of low voltage telephony are long passed. We all use mobile communications devices, but these have to be charged. And in any event how long will cell-phone masts continue to operate in the absence of power? In practice, it is 2-4 hours at most.

Domestic refrigerators and freezers will stop working. So will those in small retailers. How long will those in major supermarket outlets last? And in these days of just-in-time deliveries how well will wholesale supplies hold up assuming that the distribution network is functioning? In Lancaster, the ATMs stopped working, so how long would the financial system continue to function?

In 2004, the UK’s domestic Security Service (also known as MI5) reported that the UK was “four meals away from anarchy”. The early weeks of Covid-19 saw people in the UK hoarding toilet paper, pasta, and wholemeal flour. It does not take much to imagine the implications of the sort of disruption to food supplies that would ensue from some of the events mentioned here, on civil order. The urban riots in 2011 showed how easily the thin blue line of police can be overwhelmed.

There are a number of events that might trigger such disorder. Some of these would be malign attacks on our electricity infrastructure, for example, a cyber-attack. This is worryingly plausible, given that such tactics were deployed against Ukraine in 2015, and the US Defense Science Board has also catalogued attacks against the US power grid. Even a concerted physical attack would potentially cause disruption. In July 1996 an IRA plot involving 37 explosive devices, designed to destroy the six sub-stations providing London’s electricity, was disrupted and the bombers arrested. Then there is the possibility of an electro-magnetic pulse (EMP) attack, involving a nuclear blast in the atmosphere. This is something North Korea has contemplated as an end-product of their nuclear programme. Such an attack would blow out electric systems and would have very widespread consequences.

Similar effects could be triggered by extreme space weather; or the sun’s equivalent of an EMP attack. On September 1st 1859, Richard Carrington observed a massive solar flare which the following day led to brilliant red, green and purple auroras all over the world (the “Northern Lights” were seen in the Caribbean). This was associated with widespread burning out of the telegraph systems. 163 years later, and whilst some of our systems may be better protected, we are far more dependent than we were then on electrical networks. Indeed, in 1986 a huge solar storm crippled power supplies in Quebec. And on 23rd July 2012, a coronal mass ejection (of the same scale as the Carrington event) narrowly missed Earth. Had it not missed, the economic cost is estimated to be $2 trillion and large parts of the planet would have been without power for months, if not, years.

Terrestrial weather can also have more severe consequences than those causing the power failures in Lancaster. Hurricane Harvey and Super Storm Sandy both led to prolonged electricity outages; and in Puerto Rico Hurricane Irma left 8million people without power for months. Extreme weather events are becoming more frequent with climate change.

It is clear that Programme Yarrow is based on plausible scenarios. Whilst some of these may be individually remote or rare, the consequences of any of them occurring would be devastating for the communities affected. Therefore, the UK government is right to take such contingency planning seriously. Now it should encourage the rest of us to do so too. Businesses and individual households should be ready to play their part, and a good start would be for the government to revise its 2018 guidance “Preparing for Emergencies”. This is useful, but very focussed on weather and flood risks. As Programme Yarrow highlights, there are many other risk areas we should all be preparing for.

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