The cause of the blackout that occurred in the Iberian Peninsula on Monday 28 April 2025 is still unknown and any interpretation remains speculation.
While demand-side flexibility (DSF) may or may not have prevented the blackout, a more robust and widespread activation of flexible demand can be a strong and cost-effective pillar of a resilient power system.
A rapid response capability is crucial in systems with high renewable penetration and activation speed is critical: the faster the flexible demand kicks in (within seconds or minutes), the more effective it is at preventing the grid frequency from falling dangerously low.
For this to happen, TSOs must open all Ancillary Services to all resources, including demand-side assets in homes, offices, electronic vehicles, SMEs, and industries. This huge potential would help maintain balance and could prevent damaging cascading failures. To keep costs for consumers low, TSOs must procure frequency services in a market-based way.
In particular, an open, market-based procurement of Frequency Containment Reserve (FCR) and Fast Frequency Response (FFR) from flexible loads and energy storage facilities, including home batteries and electric vehicles, is crucial in Member States with increasing variable renewables in the energy mix to strengthen inertia.
smartEn welcomes the establishment of an expert panel by ENTSO-E and ACER to investigate the incident and, whenever recommendations are put forward, urges to analyse the contribution of flexible demand in improving grid resilience, reducing the likelihood and impact of future blackouts. We stand ready to contribute to the work of the expert panel.
