QAZAQ GREEN.  On April 28, 2025, mainland Spain experienced a complete electricity blackout due to a major failure in its national power system. In a joint technical report, Red Eléctrica de España (REE) and the Ministry for the Ecological Transition and Demographic Challenge disclosed the root causes behind the massive outage.

According to the report, the incident was triggered by a combination of factors, including unstable performance at a large solar plant in Badajoz, multiple frequency oscillations ranging from 0.2 to 0.6 Hz, a lack of reactive power, and uncoordinated behavior of generation units. A critical aggravating factor was the high level of electricity imports from France—peaking at 3,800 MW—which led to a full system desynchronization.

The blackout unfolded in five stages, culminating in a system-wide voltage collapse across the Iberian Peninsula. Within seconds, Spain and Portugal were disconnected from the European grid, triggering emergency protocols such as the shutdown of cross-border interconnections with France and Morocco, pump stations, and large-scale consumer outages.

A special 28-A Analysis Committee concluded that current regulations, grid operation rules, and system design were insufficient to prevent such a cascading failure. Key recommendations include:

• upgrading voltage control systems;

• tightening technical standards for renewable energy facilities;

• deploying synchronous compensators;

• enhancing real-time monitoring infrastructure;

• introducing rapid-response tools and updating the regulatory framework to reflect a high share of renewables.

The report underscores the growing complexity of power systems during the energy transition, emphasizing the need for balanced development of both digital and inertia-based infrastructure.