Why Did Spain’s power grid fail this week and what are the implications for UK power supplies ?

 

Introduction

We are living through a time of great change – and a challenge to our way of life. The fundamental reason behind this is a developing imbalance between the resources we are able to supply for our populations, and the demand they are placing on them. Our unrestrained world population growth over the past half-century has now caught up with us with a vengeance, and is rapidly outstripping our available resources.

As far back as the 1970s, this imbalance was predicted to come to a head in the early to mid-2020s. At that time, the environmental movement was just a pale shadow of what it is today, and 'net zero by 2050' hadn’t even been considered.

The arguments about whether climate change is actually occurring have largely subsided now in the face of the overwhelming evidence that the planet's atmoshphere is heating up, particularly in the polar regions; these have been replaced by disputes as to how much of a contribution man-made greenhouse gas emissions is actually making, and how we should actually go about dealing with the problem. 

The unfortunate accident of a 2^nd Trump presidency generated by the US electorate last year has thrown environmental concerns (and many other things!) to the winds in the US, which also happens to be one of the two biggest emitters of greenhouse gases. The other, China, although more actively aspiring to promote green energy, and continuing to provide a cheap and plentiful supplies of solar panels (where Trump tariffs permit!), is showing little signs of reducing its own headlong consumption of fossil fuels.

In the UK, doubt is already beginning to manifest itself as to whether we should really be ‘going hell for leather’ to green our economy and our power supply, given our existing level of government debt and the profound effect that obsessive drive towards greening 'at all costs' could have on our standard of living. As we will see, if progressed at the pace adopted by the Labour government, the transition is likely to be a painful and somewhat risky one, and it needs to be more carefully phased to minimise the threat - both to our well-being...and our security.

Power Grids and their Vulnerabilities

Power grids the world over are under strain – one of the main reasons for this is the ever-increasing demand we are placing on them, and the high cost of upgrading their infrastructure in order to meet this. Demand for electricity has been on a rapidly rising trajectory since the early 2000s, and the 2020s have exacerbated this trend with the developing focus on electrifying just about everything, from our heating systems to our cars, trains and buses.

The problem is that, like most of our key infrastructure, our power grid just hasn’t kept up - much of the UK’s grid is now becoming antiquated, and although some upgrading has occurred, the process is costly and is difficult to achieve wholesale while keeping the lights on for the rest of us. Significant quantities of available wind and solar power reguarly go to waste because the grid can't handle them. Privatisation certainly hasn't helped here, with major infrastructure improvements being a 'no-no' as far as maintaining profit margins is concerned. 

Governments on either side of the political fence have also been reluctant to force the issue, given the up-front cost to the exchequer.  Voters are also well aware that our electricity is already the most expensive in Europe and our bills are weighed down by existing ‘green’ levies of one sort or another, and any additional imposed costs would be likely to exact a severe electoral penalty, given what we've just seen happen at the ballot box in the local UK elections. The Labour government may well start to think again about its 'renewables or bust' approach, particularly now it has received a well-deserved 'good kicking' in the recent local elections, with the promise of more to come if it doesn't change its ways.

The other source of strain on our grids, which is less well understood, but equally risky, are the effects of the inherent variability of renewable energy. This can best be exemplified by considering what happens to renewable output when the ‘wind doesn’t blow and the sun doesn’t shine’. Both of these conditions often coincide with quiet anticyclonic weather and their effects can set in quite quickly, sometimes simultaneously….and both can end just as quickly, resulting in rapid surges and drop-offs in inputs to the grid. 

The power grid that has been with us since WW2 was never designed for this type of rapid fluctuation, being configured for coal and gas-fired power stations, with an added nuclear contribution from the 1960s. All 3 of these 'conventional' sources are readily controllable and much more predictable. Although our grid system has made great strides in its adaptability since renewables started to come on stream in earnest in the 2000s, it still has to cope with massive fluctuations in both wind and power throughout the year, as well as a large influx from new wind and solar farms, all of which need reliable and consistent grid connections to make best use of their input.

If that wasn’t enough cause for concern, our grid controllers have yet another worry to contend with – hackers. Like much of the rest of our essential infrastructure, control and management of the grid is heavily dependent on the internet connections.

This renders it, and therefore the population it serves, highly vulnerable to attacks by hackers of any sort, not the least of which is the hostile state-controlled variety, of which we know there are armies in China and Russia working tirelessly to disrupt our western way of life. Indeed, so important is this inherent vulnerability that it may yet prove to be a decisive factor in the outcome of WW3. One of the easiest ways to bring a country to its knees is to cut off its power supply, and hostile governments are all well aware of this. The numerous examples of organised hacker groups brazenly disrupting UK businesses with ransomware attacks merely highlights our lack of resilience and will hopefully spur on the authorities to tackle the problem head on.

What Just Happened in Spain and Portugal ?

I suspect it was probably quite a shock for most of us in UK to wake up to the news that the Spanish and Portuguese power grids had both failed extensively on Monday April 28th (the Spaniards will have had even more of an unpleasant surprise !) Although relatively rare, this type of wholesale shutdown of a power grid is always worrying wherever it happens because of what it implies, i.e. major disruption to the day to day routine of two of our close Western European neighbours. This introduces the question of whether it could actually happen here at home.

What was even more of concern is that the authorities in both countries seemed to have no idea  exactly why it happened…and they still don’t have a definitive answer more than a week after the event. Although power has now been restored, and things have now returned to 'normal', until the root cause has been identified, it won’t be possible even to address the risk, let alone do something about mitigating it.

Various theories are beginning to trickle out from the Iberian peninsula about the cause. One of the original front runners, a cyber-attack, seems to have already been ruled out.  A plethora of other possible causes have been earmarked as more or less likely to have contributed. The variability effect of renewables discussed above, particularly solar, may well have  been a factor – there was a sudden increase in sunshine in the Iberian peninsula over last weekend after a storm system moved away, coinciding with a large increase in solar power availability and plenty of wind turbine output. This probably wasn’t the only potential trigger, however, with some now pointing to a rarer weather phenomenon over Spain causing wide ac frequency fluctuations. This can trigger automatic shutdowns to prevent damage to sensitive components. Thus, a series of coincident problems is likely to have been responsible, leading to a reflex general ‘protective’ shutdown of the entire grid in response, and the exact combination of causes may be difficult to pin down.

What are the implications for us in UK ?

Whatever  the root causes of the ‘Spanish episode’ actually turn out to be, what all this highlights is the general vulnerability of our western European power grids, and the need to upgrade them – preferably before we put any more excessive demand on them and risk them ‘falling over’. Although no system is 100% reliable, we can and should do more to make them more resilient, given our total dependence on electricity 'on tap'.

It’s clear that many of our grids are already creaking at the seams due to increasing supply demand (much like our own UK heathcare system !) and we risk partial or complete collapse if we don’t do something about it urgently.

Governments need to take the lead on this, give its importance to our security and way of life, and the high costs involved in upgrading infrastructure. In tandem with this, in the UK we need to put the brakes on decommissioning of our fossil fuel power generation, and allow further extraction of North Sea gas and oil. Only by maintaining extraction will be have enough locally-available and geopolitically-protected backup during the power transition to cover demand when renewables aren’t available (we also depend on oil and gas as feedstocks for our chemical industry). 

We also need to make sure our grid can cope with any excess inupt when renewables are plentiful, and do so in a timely way. The need to provide this local capacity independently of foreign players should be obvious in the light of Putin’s recent ‘adventures’.

One way of minimising the renewables load on the grid, and boost our local generating capacity would be to promote domestic solar . Why would this help ? 

We have vast amounts of unused roof space directly above our heads, and these could provide for power self-sufficiency during daylight hours for the majority of households for much of the year. More importantly, because much of the power generated would be used locally, it would not place much extra strain on the grid. Contrast this with the output of  large solar farms, which we now see adorning our countryside and occupying prime agricultural land in ever increasing numbers, and must feed their output directly into the grid during daylight hours.

Unfortunately, in these straitened times, relatively few of us can afford the price of even a basic solar installation (minimum £10,000 for a 10-12 panel system + storage battery), and the government have steadfastly refused to provide any non- means tested subsidies (contrast this with the generous £7,500 government ‘bribe’ which is available non-means tested to anyone who's prepared to install a heat pump system).

The other big issue is the absurd proposed rate of new house-building - the sheer impracticability of building 1.5 million new houses before 2029, let alone finding buyers who can afford  them all, has already been considered in a previous blog. What doesn't seem to have been allowed for (or even admitted to!) by governments of either complexion is the additional load all these additional houses will place on our power grid....and our water and sewerage systems.

Final Thoughts

Although at the time of writing, we still don’t know what caused the Spanish and Portuguese power outages on April 28^th, it’s likely that a combination of factors will probably prove to have been responsible. What is certain is the vulnerability in our power supplies that it has highlighted.

This has important implications for the fate of our own UK grid. We need to ensure that this is upgraded urgently, and preferably before we add any further demand or additional online supply burden, to it. 

We also need to adopt a more realistic and sensible approach to phasing out fossil fuels – while we certainly do need to reduce extraction and consumption to a minimum, and attempt to mitigate its effects, too precipitate a downward trajectory could well jeopardise our way of life. 

The key question on the minds of many of us is: "..given that we in UK are only responsible for 1-2% of total world greenhouse gas emissions at most, should we really subject ourselves to the substantial degradation to our quality of life that a headlong rush to net zero would entail, when neither of the two biggest contributors are prepared to do the same ?". 

I'll leave the reader to wrestle with that one.....

First published 30.4.25; Revised 9.5.25