Power being restored to Portugal and Spain as focus turns to cause of outage
Communication antenna tower. Image courtesy 123rf
Spanish grid operator Red Electrica has reported on X that as of 7.00am this morning, 99.95% of demand (25,794 MW) had been recovered after a massive power outage hit the Iberian Peninsula yesterday.
Portuguese energy company REN has also reported that it has “restored the operation of all substations of the National Transport Network…” and the network is now “perfectly stabilized.”
The unprecedented power outage occurred yesterday at 11.33AM and left millions of people in Spain, Portugal and parts of France without power. Trains, traffic lights, telecommunications, air traffic and even the Madrid Open tennis tournament were impacted.
The outage was caused by a sudden power drop of more than 10GW. The exact cause of this drop in demand remains unclear, with no official communications being released by grid operators or authorities. One of the many suggested possibilities is that a rare atmospheric event caused anomalous oscillations in the very high voltage lines, leading to synchronisation failures between the electrical systems.
According to a REN statement: “A significant voltage fluctuation in the Spanish grid at a time when Portugal was importing energy from Spain. With this fluctuation, the control and protection systems of the Portuguese power plants, as expected in a situation with this configuration, shut down, causing the blackout.”
Initial estimates were that it could take up to 10 hours to restore power. By mid-afternoon, however, voltage recovery efforts were well underway in the north, south and west of the Iberian peninsula, a process which needed to be carried out gradually to avoid overloading parts of the grid as each generator connects.
Nuclear power plant production was also impacted by the outage, which meant combined-cycle and hydroelectric plants across the region were reactivated to enable supply could be recovered as soon as possible.
In Portugal, REN resorted to its black start capacity at the Tapada do Outeiro gas power plant, which allowed it to restore energy to areas of Greater Porto. The Castelo de Bode Power Plant together with support of some connections with Spain, allowed supply to be restored to areas further south of the country.
Stay updated with Enlit’s live blog: Spain and Portugal hit by massive power outage
Power outage puts grid resilience front of mind
While speculation around the cause of the event remains, there is certainly no doubt about the fact that boosting grid resilience needs to be a priority for Europe, especially for island or peninsula grids.
Montel Analytics director, Jean-Paul Harreman, noted that a blackout of this scale has not been seen since the 2003 Great Italian blackout, or the Turkish blackout of 2015 and emphasised the need to improve grid resilience for island and peninsular grids.
“Countries that are on the edge of, and more isolated from the synchronous European grid tend to more easily see grid frequency deviations.
“In island systems like GB and Ireland, or peninsular systems like Italy and Spain, the AC synchronous interconnectivity with other countries is much lower, leading to a more vulnerable grid as flexibility and resilience has to mostly come from the inside,” he said.
Harreman added: “It will be interesting to read about the atmospheric phenomenon that was observed today and the likelihood of this occurring again in the future.”
Phil Hewitt, director at Montel Analytics also weighed in: “Grid disturbances can be ridden out to a degree in regular times but on this occasion, there was a lot of non-synchronous generation on the network which made it more vulnerable.
“Grid operators need to invest in inertia technologies like synchronous condensers to support the drive for more renewables. Investment in fast acting balancing reserves such as batteries also provides extra resilience as we have seen in markets like GB and Ireland.”
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Wanda Buk, managing partner at Polish legal firm Business Law House and former board member of energy company PGE and Poland’s electricity association PKEE, said: “The recent blackout is a stark reminder of how critical infrastructure resilience has become. While the exact cause of today’s outage is still unknown and could stem from various factors, what is clear is that depriving a country of electricity — even temporarily — can seriously destabilise its economy, public services, and security.
“As we transition to more complex and decentralised energy systems, ensuring stability, redundancy, and robust contingency planning is no longer optional — it’s a necessity. Now is the right time to have an honest, serious conversation about how we future-proof our infrastructure against increasingly frequent and unpredictable challenges.”
Buk’s sentiments were echoed by Andrew Gordon, Managing Director for the UK and Ireland at power management company Eaton: “Today’s outage is a reminder that energy resilience must be a strategic priority for businesses.
“Not only is it about prevention, but also how quickly and safely businesses can restore power when disruption strikes. Right now, organisations across Spain and Portugal will be working to get back up and running again to ensure financial and reputational damage is kept to a minimum.
“Even for those unaffected, this should be a wake-up call to make sure they are investing in the right technologies that can safeguard them from such costly and disruptive situations.”
Originally published on Power Engineering International.
