5 seconds.

15 gigawatts.

60% of a nation’s supply of electricity.

12 hours of darkness.

This was the reality faced by tens of millions across the Atlantic in Spain and Portugal on Monday.

It all started at 12:33 p.m. local time (5:33 a.m. in Texas). In a matter of seconds, three things happened, disrupting the flow of electricity in Spain – and neighboring countries.

First, the Spanish electrical grid faced a minor disturbance, one that had no lasting effects and from which the grid fully recovered, according to the director of services for system operation for Red Eléctrica de España (Spain’s national power company, abbreviated as REE), Eduardo Prieto.

Then, in just 1.5 seconds, the grid disconnected again. But, this time, the grid did not recover – instead, it caused several “‘operating variables’ of the system” to degrade, causing two disconnections, severing the Spanish grid from French connection lines and causing a “‘massive generation disconnection.’”

The nail in the coffin, however, was the sudden drop of 15 gigawatts of energy from the Spanish electrical supply, using up about 60% of the nation’s electricity in a matter of seconds.

And that was when the much-battered Spanish electrical grid finally gave out.

There were many proposed reasons for the collapse of the electrical grid, but nothing so far has been confirmed.

The most obvious grounds for the blackout would be an act of cyberterrorism: hackers sawing away at the electrical grid until they finally shut down the power of a nation – and parts of two others. In fact, some Portuguese and Spaniards wondered if the blackout was “hacking from Russia… [or] an act of terrorism,” according to CNN. However, officials investigating the cause of the blackout, including Prieto, have more or less ruled out the possibility of a cyber attack, although no “definitive conclusions” have been made.

Monday’s outage isn’t Europe’s first widespread blackout – in fact, just last year, the Balkans faced a (much more brief) blackout during a heat wave with temperatures skyrocketing to over 100 degrees Fahrenheit. However, the temperatures on Monday – while still hotter than the average in April, particularly in the hours following the power outage – are also not thought to have caused the blackout.

It is important to note that many European power grids are interconnected, allowing an outage in one area or one country to easily spread to another, like how Monday’s outage seeped into parts of France.

Another popular theory is the belief that too much renewable energy caused the mass outage. Although this theory, as opposed to the aforementioned two, might seem outlandish, there’s much more than first meets the eye.

According to Reuters, Spain is one of the biggest renewable energy (including solar and wind power) producers in Europe, sparking concerns over the “volatility of supply from solar or wind” and whether this volatility fostered vulnerabilities in the nation’s power systems.

These concerns gained traction when the parent company of REE, Redeia, published its annual report in February which acknowledged a risk to the power systems due to disconnections caused by “high penetration of renewables without the technical capacities necessary for an adequate response in the face of disturbances,” according to Reuters.

This theory acquired even more credibility in light of the knowledge that Spain’s nuclear plants were not in operation during the time of the outage, causing some, including energy expert Carlos Cagigal, to suggest that this caused renewable energy sources alone to feed “saturated substations,” according to Reuters. From there, a single substation failure without backup – presumably due to the offline nuclear plants – triggered safety protocols, causing the entire system to disconnect.

However, Spanish Prime Minister Pedro Sanchez has ruled out this possibility, citing the low demand and high supply at the time of the blackout, as well as the fact that the nuclear plants in question still aren’t back online, despite the almost absolute restoration of power by Tuesday morning.

Yet another semi-popular theory has to do with “induced atmospheric vibration”. Induced atmospheric vibration refers to the phenomenon where sudden changes in temperature and air pressure, like explosions, natural disasters, or heat waves, can induce oscillations or vibrations in power lines. These induced changes place additional stress on electrical grids and related infrastructure, increasing the likelihood of a blackout.

One example of this phenomenon, presented by The Conversation, centers on heat waves.

Heat waves occur when there is a sudden increase in temperature. This sudden and rapid increase in temperature of a “part of Earth’s surface” can cause the air above that area to also heat up, making it much less dense and causing it to expand (think ideal gas law). Warm air in one area collides with much cooler and much more dense air in the surrounding area, creating waves that extend outward in a ripple-like fashion. These waves can then, as mentioned earlier, “bump into” power lines and induce them to oscillate, stressing the power grid. 

While this theory has not been outright denied by the Spanish or Portuguese government, it has also not been corroborated, although The Conversation reports that REN, the Portuguese grid operator, originally reported this to be the cause for the blackout, before refuting this claim.

The true cause of the blackout – while yet to be ascertained – will surely be determined in the near future.

What is of exponentially more concern, however, is the inextricable interconnection of electrical systems in our daily lives. Monday’s blackout – and the challenges faced by many – reflect the world’s growing dependence on electricity, for better or worse.

Now, when we refer to a dependence on electricity – particularly in the context of Monday’s blackout, the main point of concern is not in the stories of the failing traffic signals, failing refrigerators in bars and restaurants, and the failing public transit. 

Rather, it’s in the stories of the failing electronic keypads that kept individuals from getting inside their own apartments. It’s in the stories of broken card readers born of an overreliance on electronic forms of payment.

Electricity has undoubtedly improved the human experience and quality of life for billions. But, at the same time, it has seemed to foster a near overdependence on something that is so… fleeting. Something that can so easily break and has broken countless times. 

By no means should we live in fear and stop using electricity altogether. But perhaps it is time to temper this almost obsessive use of the digital with the use of the analog. 

Electricity is like water – it can just as easily give to our lives as it can take from them. 

And so, it is imperative that we step back from diving deeper and deeper into the electrical world and instead question the need for electronics in every single facet of our life before we drown in the torrent.