On April 28, 2025, a massive and sudden power outage struck large parts of Spain and Portugal, causing disruption to daily life and halting essential infrastructure – with the Spanish government citing the event as “the worst power outage in the country’s recent history”.
Power failure impacts infrastructure
The outage has caused disruption to public transport, phone lines, and ATM machines in both Spain and Portugal, with traffic light failures prompting safety concerns. Airports, hospitals and emergency services in both countries are also experiencing disruptions, relying on backup generators to maintain operations.
The blackout began around 12:30 PM CET and affected major Spanish cities including Madrid, Barcelona, Seville, and Valencia, as well as Lisbon and Porto in Portugal. While the cause remains unknown (at the time of writing), Spain’s national grid reported a sharp drop in power demand from 26GW to 12GW within seconds. Portugal’s grid – Redes Energéticas Nacionais – said that 8.16 gigawatts (GW) were connected on the consumption side, dropping to only 0.6 GW.
This incident highlights the critical importance of robust backup power systems. Hospitals, emergency services, and airports have (so far) been able to maintain essential operations thanks to generators and backup power systems, reinforcing their role in ensuring public safety during unforeseen disruptions.
The impact of power failure on businesses
Newspapers are reporting that many businesses have been forced to close for the day and factory activity has ground to a halt. For some, this will mean the financial losses caused by missing a day of trading. For others, missed order deadlines and spoiled stock could have far-reaching financial repercussions.
According to El Pais newspaper, the Ford Almussafes car plant is currently without power, with production lines completely stopped, and truck manufacturer Iveco, which has factories in Madrid and Valladolid, has also halted operations while waiting for power to be restored.
Power resilience planning
If power is critical to your business, having backup power in place is a sound investment.
Start by identifying your critical loads. Which systems and operations must stay operational during an outage? Calculate their total power requirements, factor in the desired runtime, and always include a safety margin for unexpected fluctuations. Ideally, consult with energy experts to ensure your calculations are accurate and your backup power/generator is appropriately specified.
Simply installing a backup power system isn’t enough. Regular maintenance and testing are just as important. Even backup generators can fail if not properly maintained. Testing your generators under load conditions – ideally using a load bank – is crucial to confirm they will perform as expected when needed.
The manufacturer will generally test generators and uninterruptible power supply (UPS) systems in the factory before delivery. Many businesses will assume this is all that’s needed, and that the generator will work when called upon. In fact, generators can be sensitive to changes in temperature, humidity, and fuel, as well as the impact of lifting, moving and transportation of the equipment. For this reason, backup power systems must be commissioned accurately and tested in situ.
Once installed, testing and maintaining the system is critical. To do this, a load bank can be used to apply a “dummy” electrical load to a generator. This enables the effective testing of fuel, exhaust, cooling systems, and alternator insulation resistance in a safe and controlled manner. It also helps to identify common generator system issues without incurring the costs associated with major failure or unplanned downtime.
If the fuel, exhaust and cooling systems are not tested, your backup power system – the very system you rely on in an emergency – could itself fall into the very high-risk category.
As investigations continue, the outage in Spain and Portugal serves as a stark reminder of the need for continued investment in backup power systems to safeguard against future crises.
Without regular testing, you’re relying on hope, not resilience. Speak to our team to find out more.
