The blackout in Spain and Portugal earlier this year showed just how devastating a power failure can be.

Even though the UK has one of the most reliable networks in the world, NESO has sought to future-proof the network and consider ways to protect supply.

On April 28, parts of the Iberian Peninsula were without power for up to 19 hours. This sudden loss of electricity left many homes, businesses, and essential services without power or relying on back-up supplies and must have been a frightening experience. This event highlights the critical importance of having a reliable and resilient energy system.

As a result, NESO has produced a report, Future-Proofing GB’s Power System: Reflections on the April 2025 Iberian Event, which examines what lessons can be applied.

The report explains, NESO has worked with the energy sector to implement rigorous planning, testing, monitoring, and control measures to ensure the resilience of power system. The report finds that NESO has taken action to mitigate many of the risks seen in Iberia and must continue to build on existing planning, testing, and system monitoring capabilities, particularly in voltage management.

Other steps to be taken include monitoring, data and asset availability from Transmission Owners (TOs), and driving improvements. Resilient communications between control centres, real-time data, and coordination between system operators and network owners must be prioritised. NESO’s report explores these findings and other issues in far more detail.

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