On April 16, Red Eléctrica, Spain’s electricity company, proudly announced that renewable energy generation had met the country’s demand, declaring, “The green transition is progressing.”
Yet, less than two weeks later, Spain and Portugal experienced an 18-hour blackout that disrupted daily life—forcing businesses and schools to close and bringing trains and mobile networks to a halt.
Officials have released limited information about the blackout’s cause. However, the event exposed how Spain and Portugal—often highlighted as renewable energy success stories in Europe—are also particularly susceptible to outages due to their relative electrical isolation from the continental grid.
“This disruption serves as a stark warning,” said energy analyst Pratheeksha Ramdas. “Future grid failures could have even more serious consequences.”
What Role Did Renewable Energy Dependence Play?
The widespread blackout raises concerns over the robustness of the power infrastructure in Spain and Portugal, and to some extent across Europe. Both countries have heavily invested in renewable energy sources such as wind turbines and solar farms.
Last year, over half of Spain’s electricity came from renewables, a significant increase from just a quarter 15 years ago. This rapid growth placed Spain at the forefront of Europe’s renewable energy transition, resulting in lower electricity prices and reduced reliance on fossil fuels.
Nonetheless, this shift may have also increased the grid’s vulnerability to outages like the one on Monday. Ramdas explained, “Higher shares of renewables in the grid make it more prone to these kinds of disturbances.”
Traditional generation sources such as gas turbines and nuclear plants provide rotational inertia, which helps stabilize the grid against fluctuations common with intermittent energy sources like wind and solar.
When Spain’s grid became unstable around midday on Monday, analysts suggest the system might have been easier to maintain if conventional power sources like natural gas or nuclear turbines had a stronger presence.
“This stored rotational energy can help maintain grid frequency until sufficient backup capacity is activated,” explained Henning Gloystein, Eurasia Group’s head of energy research.
The blackout may strengthen arguments for retaining conventional power plants. Gloystein noted that Germany plans to build gas-fired plants to support renewable energy integration.
How Is Europe Preparing for Renewable Energy Growth?
As renewables expand across Europe, upgrading electrical grids and developing energy storage systems have become essential. However, according to the International Energy Agency, investments in grid infrastructure over the last 15 years have lagged behind the doubling of investments in alternative energy sources.
Spain requires increased investments in grid infrastructure and additional storage facilities such as batteries to provide backup power, said Federico Santi, a senior analyst at Eurasia Group.
“They’re almost victims of their own success,” he remarked.
Calls are also growing for enhanced investments in critical energy infrastructure beyond renewables. In March, a major outage at London’s Heathrow Airport caused by a fire shut down one of the world’s busiest airports for an entire day, disrupting over 1,000 flights and raising questions about infrastructure resilience.
What Is an ‘Energy Island’?
Spain and Portugal are often described as an energy island. Although Spain is connected to France via electrical cables, the volume of electricity that can flow through these interconnectors is only a fraction of what is transferred between Germany and its neighbors. Portugal relies entirely on Spain for its electricity supply.
Interconnectors help balance electrical systems daily and act as emergency energy sources during crises. During the blackout, France cut its exports through these links to prevent the outage from spreading to Central Europe, exacerbating Spain’s energy deficit and intensifying Portugal’s challenges.
Once the situation stabilized, France resumed electricity exports to Spain, aiding the country in restoring its grid. Greater interconnection with the rest of Europe could have allowed the Iberian Peninsula to recover more quickly.
Santi expects several projects aimed at improving grid connectivity to gain momentum following the blackout. He added that this could increase pressure to delay or reconsider Spain’s planned nuclear phase-out scheduled for 2035.
Does This Represent a Setback for Renewable Energy?
European countries are recognizing that advancing renewable energy and electrifying economies will falter without increased spending on grids and related infrastructure, including batteries and other rapidly deployable energy sources.
Greater attention and investment are needed to manage renewable energy effectively, given its variable nature dependent on wind and sunlight.
“Achieving net-zero emissions doesn’t have to mean power outages,” said Georg Zachmann, senior researcher at Bruegel, referring to emission reduction goals.
