Spain’s blackout of 28 April was triggered by excess energy and inadequate voltage control, coinciding with solar farms shutting down.

The official Spanish report identified an overvoltage problem with a multifactorial origin as the issue, with the system having insufficient voltage control capacity, leading to fluctuations that affected the system's operation and generation facilities that were then disconnected.

These fluctuations coincided with reductions in solar generation, possibly driven by solar farms shutting down generation as power prices fell.

Spanish solar associations have issued the following statement: “The investigation confirms that managing an electricity system is a complex and multi-faceted undertaking and is of great societal importance. Going forward, the Iberian blackout must be a moment of learning. Solar PV already has the capacity to control voltage, but regulations did not allow its application.”

Furthermore, they have called for accelerated investment in grid resilience and system flexibility, especially through grid-forming inverters and battery storage.

The associations behind the statement were the UNEF (Spanish Solar PV Association), APREN (Portuguese Association Of Renewable Energy), SolarPower Europe, Global Solar Council, and Global Renewables Alliance.

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