No answers likely on blackout causes 'for months,' says government

Spain’s mass electricity blackout last week has raised the alarm over the country’s energy storage deficiencies

More than a week after a major blackout left much of mainland Spain without electricity, the cause remains unknown and the government has admitted that investigations into the incident could take between three and six months. During that time, all hypotheses remain open, including a possible cyberattack.

“We need to know who was responsible and what happened. That will take time,” government sources said. Investigators are currently examining data from so-called “black boxes” owned by private electricity operators, who have been officially designated as “an investigated party”.

President Pedro Sánchez has asked both national grid operator Red Eléctrica and private electricity firms to provide full transparency and assume responsibility. A domestic inquiry, led by the Ministry for Ecological Transition, is running alongside a European Commission investigation. Brussels has given Spain three months to report its findings, while it will deliver its own conclusions in six months, potentially delaying any clear answers until late 2025.

Related story: Check if you are entitled to compensation for losses caused by the blackout

The government is firm that companies involved in the sector should not take part in the investigation, citing a conflict of interest. “They have to provide the data,” officials said, adding that the electricity grid is almost entirely in private hands, despite Red Eléctrica’s semi-public status. In the meantime, the government has announced an investment of €1.157 billion to bolster cybersecurity and cyberdefence, aligning it with wider military spending plans.

The blackout has reignited debate about Spain’s energy infrastructure, especially its lack of storage capacity for renewable electricity. Although 56.8% of the country’s electricity in 2024 came from renewable sources – a major boon for the environment and the green revolution – much of that energy was wasted due to the absence of proper storage systems.

Experts agree that energy storage is now critical. Renewable sources like solar and wind are not constant, so storing excess energy for use during low production periods is essential to prevent future blackouts. Green Renewables stresses that production and consumption don’t always align, and without reliable storage, clean energy cannot guarantee a steady supply.

Technologies such as battery cells, hydroelectric pumping, thermal storage and hydrogen fuel cells can all help bridge this gap. Lithium-ion batteries are currently the most promising, due to their efficiency and compact size, although they remain costly.

Greenpeace has highlighted the need to develop both shared and individual self-consumption systems for Spain, arguing that people should be compensated for surplus energy fed back into the grid.

Image: Isabel Díaz Ayuso