On Monday, Spain was thrown into disarray as the nation suffered a sudden and unexplained power outage, plunging millions into darkness and halting critical infrastructure. While initial speculation pointed towards a cyberattack — a fear that has loomed large in security circles for years — the likelier cause may be closer to home: an overstretched and underprepared power grid increasingly dependent on unreliable renewable sources.
Though Spanish authorities are still scrambling for answers, energy experts suggest that the real culprit may lie in the very structure of Spain’s modern electricity supply. Like Britain, Spain has shifted heavily toward wind and solar energy in recent years. While these sources are vital for reducing carbon emissions, their intermittency poses real challenges for the stability of national power grids. Unlike traditional gas, coal, or nuclear stations, renewables can’t be switched on or off to match demand — they’re hostage to the weather.
Naturally, this raises the question: could the same happen here in the UK? The answer, worryingly, is yes — and it already has.
Back in August 2019, the UK suffered a serious power disruption when a gas-fired power station in Bedfordshire and a wind farm off Lincolnshire experienced simultaneous, unrelated failures. To make matters worse, a lightning strike knocked out several smaller generators at the same time. The loss of power exceeded the grid’s buffer capacity, cutting electricity to nearly a million homes and stranding passengers as 500 trains were cancelled. Although power was restored within 45 minutes, the wider disruption lingered for hours.
In the aftermath, energy regulator Ofgem published a report warning that the UK’s pursuit of net zero targets was making the national grid more vulnerable. It advised the government to reassess grid resilience and consider the knock-on effects of a renewable-heavy energy mix.
Two main issues emerge. Firstly, unpredictability: wind and solar output can swing wildly in short timeframes. The grid must constantly match supply with demand, and traditionally, this has been relatively straightforward with controllable sources like gas or coal. But what happens when a sudden surge in demand — like the famed “kettle surge” at half-time during the FA Cup Final — coincides with an unexpected drop in wind? It’s a balancing act on a knife-edge.
Secondly, there’s the matter of inertia — the grid’s ability to absorb sudden fluctuations. Traditional power stations provide natural inertia through spinning turbines, which help smooth out volatility. It’s much like a flywheel in a car engine, absorbing the shocks and maintaining consistent output. Wind and solar, on the other hand, offer little inherent inertia. Solutions do exist, such as installing huge mechanical flywheels or advanced battery storage, but they come at a steep price.
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Compounding the problem is a geographical mismatch between generation and demand. Britain’s electricity grid was built around a handful of large coal-fired stations in the Midlands, close to population centres. Now, power is generated in remote, windswept corners of the UK, requiring it to travel much farther to reach users — increasing the complexity and risk of failure.
Furthermore, Britain is becoming increasingly reliant on electricity imported via subsea interconnectors, which supplied around 13 percent of our energy last year. This web of interconnected grids means that instability in one country can cascade into another. In fact, the blackouts in Spain also affected parts of France and Portugal — a stark reminder of how quickly problems can spread.
Spain, where around 50 percent of electricity comes from wind and solar, may be further down the road, but the UK is catching up fast. Government targets aim for 80 percent of power to come from renewables by 2030. Without robust infrastructure planning, grid upgrades, and new stabilisation technologies, Britain could be setting itself up for more frequent — and potentially more severe — outages.
What happened in Spain is not just a cautionary tale; it’s a glimpse of what could become our new reality if resilience doesn’t keep pace with ambition.
