It's hardly an exaggeration to say that modern developed societies run on electricity. Without electricity, many of the routine services - water, gas, communications - are liable rapidly also to fail, depending on the local particulars of how they are delivered. Whilst it's hard to provide first-hand evidence of this in a country where electricity is reliable, occasional short-term failures such as Lancaster in the UK can give an insight. In December 2015, flooding caused a short-term loss of power to around 100,000 people in Lancaster and a subsequent report by the Royal Academy of Engineering looked into the impact and what lessons could be learned. It's worth looking into this in some detail, as not all the effects are easy to predict at first glance, and in some respects Lancaster provides a salutary lesson into what could happen in less benign circumstances.
As the Royal Academy report describes the situation:
"Over the first weekend in December 2015, Storm Desmond brought unprecedented flooding to North Lancashire and Cumbria, including to parts of central Lancaster. At 10.45pm on Saturday, 5 December, electricity supplies to 61,000 properties in the city were cut. Electricity was progressively restored from 4.30am on Monday but was cut again to most areas at 4pm that evening. 75 large diesel generators were brought into the city and connected to local substations which allowed restoration of supplies over the next few days. By Friday, 11 December, the situation was back to normal."
Some time after the event itself, the Royal Academy convened a workshop (9th March 2016) to bring together knowledgeable people and to see what lessons could be learned from what was, effectively, an unprecedented experiment into significant loss of electricity in the UK, something not previously seen since the "three-day-week" rolling power cuts of the January-March 1974 period.
For anyone interested, the report is a must-read and, at 32 pages, not too time-consuming nor full of difficult technical jargon. A summary of some of the key effects is given here in short form for convenience, followed by some of the sobering conclusions from the workshop session.
Mains-powered radios and TVs failed due to the power being off and only people with battery-powered radios were able to receive broadcast information from outside the area. Battery-powered radios are much less common than they used to be and a shortage of batteries did not help the situation. Even the ability to find a station is an unfamiliar activity to an increasing number of people who have never used a radio [*1]. Local reporters sent to the scene by radio and tv stations found themselves unable to report due to the loss of mobile telephone coverage. One local radio station had a backup generator and a still-working telephone line and was able to provide some news relayed via the phone line. That this happened was entirely fortuitous.
The failure of communications, both telephone and internet had wide reaching implications for numerous normal activities. It made forward planning to deal with situations like school closures very difficult. The local university was obliged to close and send students home early for Christmas but spreading the message was difficult and led to misunderstandings such as "A crowd of several hundred overseas students arrived at Lancaster police station expecting to find transport". The report further notes:
"One common theme of all the organisations affected by the loss of supply was the problem of reliable communication. In the past, when services, such as water, gas, sewage disposal and electricity were provided by the local authority, much communication could be by word of mouth. With privatisation, rationalisation and the outsourcing of non-core activities, it is not surprising to find the administration for the Lancaster Magistrates' Court being carried out in Preston or the intruder alarms in a Lancaster primary school being monitored in Belfast. These arrangements rely on reliable channels of communication. During Storm Desmond, the reliability was found wanting."
Home care for the frail and the elderly was disrupted and raised important questions about social provision (including the homeless) which are explored at some length in the report.
The local hospital, blessed with standby generators, became an important impromptu community centre for the population.
The retail sector was hard hit and those stores that could have remained open were obliged to close due to Sunday trading laws with apparent great confusion as to whether any local individual had legal authority to relax the laws.
Gas, water and sewage services remained working (mostly) for the duration of the emergency, however the report notes that this was a matter of good fortune more than anything else and could have been a much worse situation since these also depend on electricity but it happened that the key components were outside the affected area.
The report wryly notes that:
"An alternative to using a terrestrial radio network is to use satellite phones. One of the participants [in the post-emergency review] described how his organisation got out its satellite phones for the emergency, only to discover that none of the staff knew how to use them."
The report also notes an encouraging community spirit of self-help emerged spontaneously amongst the majority of the people affected but warns about assuming that that would always be the case.
The report avoids alarmist language but there is a clear sense of concern that a modern connected society has grown up rapidly, much of it dependent on electronic communication and therefore a stable electricity supply, but without backup systems in place, particularly when it comes to organising what should happen when things fail.
There is a striking (to this author) picture painted of confusion sown by the lack of communications that resulted. Whilst communications for the emergency services still worked, that itself is not necessarily guaranteed in larger-scale or longer lasting emergencies. Neither are there people on the ground with the authority or training to make important decisions about, say, relaxing laws or ordnances which were designed for routine situations.
Indeed the tone of the report does start to sound alarmed when it notes that the emergency services communications network 'TETRA' is scheduled to be replaced by the use of 4G data communications which is provided by the same cellular telephone network that failed within an hour of the loss of power in Lancaster.
The report draws attention to the overall lack of clear responsibility for societal resilience, referring to the 1970s advice on what to do in case of nuclear war and, by implication, highlighting that nothing similar has been done since.
As the cited report notes, wide scale blackouts are rare in the UK. For information about the structure of the UK electricity system, the Government regulator Ofgem publishes an introduction.
Those interested can see a remarkable real-time display of demand and supply on the unofficial "G.B. National Grid Status" web page.
The strategic national importance of electricity is unsurprisingly taken seriously by UK government. In 2015 the House of Lords undertook a detailed investigation into the resilience of the network  amounting to 107 pages of evidence, conclusions and appendices.
The report looks into various aspects of current and future resilience of the network, commenting with some criticism on the lack of forward planning by recent governments in respect of ensuring enough capacity to "keep the lights on" (a shorthand term for an adequate supply of generating and distribution capacity for normal load levels).
The report notes that predicting future load levels is very difficult and that the structure of the industry is in flux as renewables and decarbonisation force changes in a structure which had remained stable over a long time, essentially burning coal in power stations distributed around the country and transmitted over the national Grid system.
Reading the report, it becomes clear that the UK electricity generating system is a long-established industry with procedures in place (even tested in the 1970s) for dealing with foreseeable network failures or capacity shortages. The majority of the report examines the forward planning for reasonably expected scenarios and finds no obvious fault: there is obviously emergency planning in place and long-term capacity planning (or lack of it) is not realistically part of an emergency scenario.
In Chapter 4 the report examines Risks to Resilience and addresses a number of possibilities:
The report specifically excludes consideration of risks caused by "geopolitical events" though one assumes that these would form a large part of the Risk Register deliberations.
In paragraph 129 the report states:
"We conclude that, as far as we are in a position to judge, the Government and relevant bodies have taken — and continue to take — steps to ensure resilience to threats, and that planning and emergency response procedures seem robust."
A detailed reading of the report brings one to broadly similar conclusions for what could be called 'normal' foreseeable events.
The report is silent on the risks posed by insolvency or bankruptcy amongst the companies involved in generation and distribution, which is odd considering that there is prior history of this affecting a strategic industry, see the closure of the Coryton Oil Refinery in 2012, significantly affecting fuel production. This is a topic for further research.
The House of Lords report broadly investigates what might be considered to be "normal" circumstances based on, predominantly, discussions with interested parties in the industry itself. It may be instructive to step outside of the normal and to look instead at the types of concerns voiced by those who specialise in considering existential risk. A newspaper article quotes Julius Weitzdörfer of the University of Cambridge Centre for Existential Risk on the subject of potential widespread loss of electricity supply in the UK for a week or more:
"I think that is a risk that is very real in the UK and it's also neglected and that sort of scenario could happen anytime, it could happen tomorrow"
The article cites the following low-risk but high-impact possible causes of the loss
The article goes on to list the impact of a large enough disruption as (some interpretation applied, not a verbatim copy)
These concerns are reflected in greater detail in the Royal Society "Black Sky" workshop held in January 2017 and this may partly be the source of Weitzdörfer's comments since it proposes cyber attacks, physical attacks and EMP as leading credible threats.
The Royal Society report is discussed in more detail in this page. A relevant comment from the report is from the head of resilience of National Grid UK that after a substantial failure of supply to several hundred thousand customers, purging and restoring gas supplies "could take months"[12:p49].