Five months after the \u00a0great blackout\u00a0 of April 28, a preliminary report from the \u00a0Technological Research Institute (IIT)\u00a0 of the Comillas Pontifical University has shed light on the incident. The report identifies an \u00a0insufficient synchronous generation program\u00a0 in the peninsular south as a “fundamental cause” of the electric failure. This document, commissioned by \u00a0Endesa\u00a0 and \u00a0Iberdrola\u00a0 and submitted to \u00a0Entso-E\u00a0, also questions the operational maneuvers executed by \u00a0Electrica de Espa\u00f1a (REE)\u00a0.<\/p>\n
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A “Collapse Due to Overtension.”<\/strong> The report introduces a new concept \u2014 a phenomenon characterized by \u00a0uncontrollable tension rise\u00a0 resulting from the disconnection of renewable generation units operating under a constant power factor. According to IIT calculations, the \u00a0safety margin\u00a0 available on the 220 kV network was 1,019 MW, but disconnections exceeded 1,600 MW.<\/p>\n <\/p>\n In practical terms, this means that when a renewable plant disconnects, the tension increases. This rise initiates further disconnections, creating a \u00a0vicious cycle\u00a0 that culminates in a total system collapse. The Comillas report asserts that this cascading reaction, unprecedented in Europe, illustrates that simply ensuring tension remains within acceptable ranges is \u00a0insufficient\u00a0 to guarantee stability.<\/p>\n <\/p>\n A Fragile and Low Inertia Network.<\/strong> The ongoing debate is not about whether to adopt renewables, but rather about how to effectively adapt the \u00a0electric grid\u00a0 to high renewable energy penetration scenarios. The IIT report identifies four critical deficiencies:<\/p>\n <\/p>\n The Chronology of a Collapse Announced.<\/strong> The government report previously mentioned a morning characterized by “atypical volatility.” At 12:03 PM, a 0.6 Hz oscillation was observed; at 12:19 PM, another oscillation of 0.2 Hz appeared, but with three times the amplitude. To stabilize the system, REE reduced exports and reconnected lines that had been disconnected. Instead of alleviating the situation, system tension intensified. By 12:26 PM, the operator ordered the start of a combined cycle plant in \u00a0Andalusia\u00a0, but the startup time exceeded an hour and a half \u2014 there was no capacity for it to take effect. From 12:32 PM onwards, the chain reaction began, culminating in a complete blackout across the peninsula at 12:33:19 PM.<\/p>\n <\/p>\n Contradictory Narratives.<\/strong> Discrepancies have emerged in the various reports on this incident. The Government initially cited REE for poor programming and an \u00a0insufficiency\u00a0 in dynamic tension control capabilities. In response, REE indicated that several power plants failed to meet their obligations to absorb reactive energy, which exacerbated the crisis. Meanwhile, the electrical companies denied any wrongdoing and attributed fault to the government and REE for their \u00a0lack of transparency\u00a0.<\/p>\n <\/p>\n The new IIT report adds another layer to this ongoing discussion by reinforcing the argument that a lack of scheduled synchronous generation was a critical factor, while also scrutinizing the operational strategies of the system operator. Notably, the analysis has garnered support from prominent international experts like \u00a0Goran Anderson\u00a0 and \u00a0Pier Luigi Mancarella\u00a0.<\/p>\n <\/p>\n What Happens Next?<\/strong> The IIT recommends several measures, including a review of synchronous generation programming, enhanced tension control, and improved coordination among all involved parties. In July, the government attempted to pass an \u00a0“anti-blackout” decree\u00a0, featuring sanctions and increased public oversight. However, this initiative failed to gain traction in Congress.<\/p>\n <\/p>\n Moreover, the \u00a0Iberian Peninsula\u00a0 remains an “energy island,” with merely 3% interconnection with France, heightening vulnerability to operational errors. Consequently, both Spain and Portugal have urged Paris to expedite interconnection initiatives, expressing frustration over repeated broken promises.<\/p>\n <\/p>\n Moving Forward.<\/strong> The \u00a0European Network of Transmission System Operators (ENTSO-E)\u00a0 plans to release a factual report next Thursday, detailing the chronology and technical data surrounding the blackout. This forthcoming document will be pivotal in guiding discussions between Brussels and Member States regarding accountability and strategic measures moving forward.<\/p>\n <\/p>\n The discussion surrounding the April 28 blackout is far from over. The Comillas report has reopened this issue with a critical reminder: the pursuit of a swift energy transition must be matched with adequate strengthening of the energy network and operational rules. The energy sector stands at a crossroads, necessitating immediate action to avert future crises.<\/p>\n <\/p>\n\n