On April 28, 2025, Spain experienced one of the most significant blackouts in its recent history. A sudden loss of approximately 15 GW of power—equivalent to 60% of the country’s electricity consumption at that time—left the entire Iberian Peninsula without electricity for several hours. This event affected over 60 million people and put the resilience of the country’s critical infrastructure to the test.

The blackout had immediate consequences across multiple sectors:

     Telecommunications: Mobile and internet networks suffered major disruptions. Many base stations are equipped with batteries or backup generators, but their autonomy is limited. Once the backup is depleted or if there are issues with maintenance or fuel supply, stations cease to operate, resulting in coverage loss.
    Transport: Rail and air transport came to a standstill. The lack of power affected signaling and control systems, causing delays and cancellations.
     Healthcare: Some hospitals, particularly those without adequate backup systems, faced challenges in keeping essential medical equipment operational.
    Economy: Estimated economic losses reached €1.6 billion, impacting various productive sectors.

Despite the scale of the blackout, data centers in Spain demonstrated remarkable resilience. According to the Spanish Data Center Association (Spain DC), facilities did not report significant incidents during the power outage. Backup systems such as generators and uninterruptible power supplies (UPS) functioned as expected.

Bjumper contacted its clients to check on the status of their facilities, and all confirmed that they had experienced no issues. This underscores the importance of having well-designed and well-maintained infrastructure.

Lessons Learned and the Importance of Preparedness

The blackout revealed the need to strengthen the country’s energy infrastructure. Although Spain is a leader in renewable energy—with a record 56% of electricity generated from renewable sources in 2024—the lack of rapid response capacity exposed system vulnerabilities. During the outage, the country had to rely on diesel generators and request energy assistance from Morocco and France to restore critical infrastructure.

Additionally, the event highlighted the urgent need to invest in almacenamiento energético. Despite having the largest solar photovoltaic fleet in the EU, Spain holds only 4% of the continent’s battery storage capacity. This contrasts with regions like Texas, which significantly increased their storage capacity after experiencing blackouts..

To enhance the resilience of critical infrastructure and data centers, the following actions should be considered:

• Investment in energy storage: Increase storage capacity to mitigate the intermittency of renewable energy sources.
• Strengthening backup systems: Ensure that critical infrastructure has adequate and regularly maintained backup systems.
• Technological upgrades: Modernize technological infrastructure to improve responsiveness and adaptability during crises.

The April 28, 2025 blackout was a wake-up call regarding the fragility of Spain’s critical infrastructure. While data centers proved to be resilient, the event underscores the importance of preparedness and investment in backup and energy storage systems. Learning from this experience is essential to reinforce the country’s infrastructure and ensure the continuity of essential services in the future.