When the Power Grid Fails, How Can You Track What Happens at Your Place?

Europe in the Dark: The April 28, 2025 Blackout and What It Looked Like

On April 28, 2025, tens of millions of residents across Spain, Portugal, and parts of France suddenly found themselves without electricity. The mass blackout, which affected nearly the entire Iberian Peninsula and parts of southern France and Andorra, became one of the largest in recent European history. It disrupted homes, hospitals, transportation systems, and digital infrastructure.

The Scale of the Outage: What Happened

Various international and regional media reported widespread impacts, with tens of millions affected across multiple countries. While exact figures vary, the blackout left large parts of Spain and Portugal completely without power, with ripple effects into southern France and even Andorra.

Overview of the April 28, 2025 Power Outage Across Europe Based on Public Reports

According to Red Eléctrica, Spain’s national grid operator there was a sudden drop of 15 gigawatts of power in just five seconds, likely caused by strong oscillations in the European grid (Source: El País). Red Eléctrica stated that neither cyberattacks nor natural disasters were involved. El País reported that the operator expected recovery to take 6–10 hours and described the incident as "absolutely exceptional".

↑ Back to Top

When Mobile Networks Struggle, Can You Still Know What’s Happening at Your Remote Property?

When the power goes out, the first thought is: Did something trip in my home? People checked their fuse boxes and looked out the window. But understanding the broader situation in those first moments was almost impossible — especially when internet access and parts of the mobile network were also disrupted.

At iSocket Systems, we monitor power status in real time through our power tracker devices installed across various parts of Europe. These are either our own trackers or those deployed by our users. Thanks to this data, we observed how the outage evolved over time and how power was restored inconsistently across the affected regions.

Despite disruptions to some mobile networks, we were surprised to find that iSocket devices across Europe successfully transmitted power outage alerts in real time. While certain carriers experienced service degradation, the mobile networks used by iSocket remained operational, allowing us to receive notifications directly from the devices. A few examples are provided below.

↑ Back to Top

Why Knowing About Power Restoration Matters

While power outages of that scale are easy to notice — and you probably don't need a dedicated device to tell you that (though it's debatable, and we'll return to this point) — the moment electricity returns can remain unknown if you're not at the remote site you're concerned about. When grid restoration happens in phases, as it did in this case, it becomes difficult to know whether power has been restored in your specific location, particularly for remote properties or critical infrastructure.

iSocket helps solve this by notifying not only when power is lost, but also when it is restored. This is especially useful when you're managing places you can't physically check — like rural homes, server rooms, or storage sites. Some locations had electricity restored in under 30 minutes, while others remained offline for hours.

We will now briefly show what we have observed in a few locations. But first, a few words about power outage alerts in events of this scale. The same principle applies here: just because a nationwide outage happened doesn’t mean power went out — or came back — in your specific place of concern.

↑ Back to Top

How iSocket Power Trackers Captured the Event

Our power tracker devices collected outage and restoration events across dozens of locations throughout the Iberian Peninsula. Below, we present a selection of data from various areas of Portugal and Spain where outages were recorded.

Snapshot of Power Outage Statistics Across the Iberian Peninsula as Registered by iSocket Power Trackers

While assembling this initial snapshot, we observed that some iSocket power trackers continued to report outages and restorations even on April 29th, indicating that the event was still ongoing in a number of regions. We plan to update and expand this data after the May holidays.

Observations from the Data

The collected data (though we didn't list all the events) reveals several patterns. In many areas, the outage lasted for several hours, often exceeding 8 to 12 hours, particularly in southern Spain and Portugal. Some regions, mainly urban areas such as parts of Valencia and Lisbon, saw faster restoration times of under 4 hours. Rural locations experienced outages extending beyond 15 and even 20 hours, which is understandable because utilities usually don't prioritize rural areas when it comes to power restoration plans.

Short-duration flickers — lasting just seconds — were observed in some places, suggesting localized resilience or quick grid rebalancing.

Conversely, some coastal regions endured multiple consecutive outages, demonstrating how restoration efforts were phased and uneven across territories.

About Power Tracking in France

We have not yet included France in this release. Our network of iSocket power trackers across southern France is extensive, and due to the volume of data, we did not have time to compile and validate it in time for this publication. We plan to add this information in a future update of this article.

↑ Back to Top

What the Blackout Revealed About Local Power Monitoring

This event clearly showed that even in countries with advanced infrastructure, large-scale power failures are possible. Millions were left not only without electricity, but also without visibility into how power was being restored — or if it had been restored at all in the locations they cared about. The uncertainty didn’t end with the outage itself: restoration was gradual, uneven, and hard to track without the right tools.

That's where power status tracking tools like iSocket come in. Devices that notify not just when power is lost, but also when it returns, provide essential visibility for remote properties, critical systems, or businesses that depend on knowing what’s happening in real time — especially when you can't be there in person.

The uncertainty didn’t end with the outage itself: restoration was gradual, uneven, and hard to track without the right tools.

iSocket provides a way to:

• detect an outage even if you're not at the location;
• receive confirmation when electricity returns;
• monitor assets across you remote locations, cities or countries;

Stop guessing and start knowing! If you need to track the power status of a property — at home, a second residence, or a business facility — we're here to show how iSocket can help.

↑ Back to Top