The Economist: Spain's power grid falters amid renewable surge

Key topicsSpain suffered a massive power outage, losing 60% of its electricity supply.Authorities are probing causes; cyberattacks and weather have been ruled out.Renewable-heavy grids raise concerns but can be made more resilient with tech..Sign up for your early morning brew of the BizNews Insider to keep you up to speed with the content that matters. The newsletter will land in your inbox at 5:30am weekdays. Register here.Support South Africa’s bastion of independent journalism, offering balanced insights on investments, business, and the political economy, by joining BizNews Premium. Register here.If you prefer WhatsApp for updates, sign up to the BizNews channel here..From The Economist, published under licence. The original article can be found on www.economist.com© 2025 The Economist Newspaper Limited. All rights reserved..The Economist .Shortly after noon on Monday April 28th, Spain’s electricity grid suddenly and unexpectedly lost 15 gigawatts of power—equivalent to 60% of its national demand. The massive drop caused most of the country’s electricity system to shut down, followed by much of neighbouring Portugal’s. Trains and metros ground to a halt and 35,000 passengers across Spain had to be evacuated. Traffic lights stopped working; hospitals cancelled all non-essential operations; and mobile phone and internet networks went dark.The chaos lasted for hours. Though Portugal recovered by the end of the day, most of Spain’s capacity was not restored until 7am on Tuesday. Red Eléctrica de España (REE), Spain’s national electricity operator, which is partly state-controlled, called the blackout “exceptional and totally extraordinary”. Pedro Sánchez, Spain’s socialist prime minister, promised to “get to the bottom” of what happened.For now, authorities are in the dark. Rumours of a cyber-attack have been dismissed by REE; AEMET, Spain’s meteorological agency, has said that it has not detected any “unusual meteorological or atmospheric phenomena”, or sudden temperature fluctuations that could be a possible culprit. Identifying the true cause may take weeks, says Mike Helmsley of the Energy Transitions Commission, a London-based think-tank.That has not stopped some from questioning the resilience of energy systems mostly powered by renewable sources. Spain and Portugal have some of the highest shares of wind, solar and hydro power in Europe: in 2024 these provided nearly 60% of Spain’s electricity, and over 70% of Portugal’s. The comparable figures for Britain, France and Germany are closer to 40%, 30% and 50%, respectively. As these percentages rise, there are fears the incidence of blackouts will too.Such pessimism may be ill-founded. Even though the initial failure seems to have occurred in south-west Spain, the source of most of the country’s solar power, at a time of day when the grid would have been basking in abundant solar, two other faults then followed hard on its heels, including one in the connection between Spain and France. Simultaneous failures of this kind could be enough to take out any grid, says Janusz Bialek, an electrical engineer at Imperial College London, as their probability is low enough to make protection prohibitively expensive. That means even fossil-fuel-heavy grids can grind to a halt, as seen in Italy in 2003. Natural-gas plants ill-prepared to handle the winter may also have contributed to Texas’s dramatic blackout in February 2021..Read more:.Spain proposes 100% tax on property purchases by non-EU Citizens.That being said, renewable-heavy systems can be particularly vulnerable to major disturbances. Electricity grids rely on inertia—the physical momentum created and maintained by large rotating machines, such as the turbines in gas or coal plants—to help smooth over frequency fluctuations. Machinery-light power sources, such as solar, have a harder time coping. In a report to the stockmarket regulator in February, REE warned that Spain’s reliance on renewables could lead to grid instability. It also warned this would be exacerbated by closing nuclear power plants, which Mr Sánchez intends to start doing in 2027.Such problems can themselves be smoothed over, says Mr Helmsley. One solution is to build in “synthetic” forms of inertia, such as flywheels, which store energy as they spin, ready to be released back into the grid if the frequency drops. Another is to add more inertia-heavy renewable sources—such as hydropower—to the energy mix. Indeed, it was a combination of hydropower and gas plants that helped generate enough inertia to help Spain restart its grid on Tuesday—a difficult endeavour that seems to have gone much more smoothly than many feared.Further investment in hydropower could provide yet more stability, says Gonzalo Escribano at the Elcano Royal Institute in Madrid. For instance, the excess electricity produced during sunny periods could be used to pump water back uphill into hydropower reservoirs, effectively “storing” it until it is needed. A grid designed in this way would be less vulnerable to sudden large-scale blackouts.Even if they are vulnerable in some ways, renewable-heavy grids can boost resilience in others. They tend to be more distributed, for one thing, because they rely on many solar or wind farms spread across a wide area, compared with large power stations, which present a single point of failure.Of course, trends other than grid-greening could turn out to bear the bulk of the blame for the Iberian power-cut. The likelihood of several faults increases as countries become more interconnected, for example, even though those connections can usually boost stability (importing extra power from France and Morocco also helped with Spain’s recovery). The trick, Dr Bialek says, is making sure that there are backup systems in place that are robust enough to cope with sudden, large-scale outages—something this week’s chaos showed was clearly missing.

The Economist: Spain's power grid falters amid renewable surge

Key topics

From The Economist, published under licence. The original article can be found on www.economist.com

© 2025 The Economist Newspaper Limited. All rights reserved.

The Economist

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