This article appears as part of the Winds of Change newsletter

We know certain things about the power blackout that hit most the Iberian Peninsula on Monday around 12.30pm local time, forcing Spain and Portugal to declare a state of emergency.

We saw, through vivid reports, how some telephone networks went down quickly. We saw how ATMs failed. We saw how people were stranded in trains and trapped in elevators. We saw that major supermarkets became cash only or closed; only a handful of petrol stations kept working; that there was traffic light chaos. We saw people out in the streets socialising, drinking and having barbecues. We learned that it was good to always have a battery-powered radio, some cash and a torch.

We saw, in other words, the fragility of a society that is so dependent on an electricity grid.

But how much do we really know about the causes of the huge outage that left millions across Spain and Portugal without electricity, and what that says about the risks to our own grid system in the UK?

The answer is not so very much that is concrete just yet.

The operator of Spain's national grid has said the power outage began when there was a "generation loss" in the southwest of the country, in which, in two separate incidents, power generation went down.

Before the blackouts, reportedly, systems were “stable”, but then, he said, the loss grew to the “point of instability”. Within a five second window, conditions exceeded the system's capabilities. It took only few seconds before it went down and following that a split occurred in the interconnections with France and the Iberian Peninsula's grid was cut off.

But that explanation doesn't really tell us why - and into that space has flooded a storm of speculation and conspiracy theory. One story that circulated online, and in news articles, was an early report that Portugal's grid operator, REN, had said the cause was a “rare atmospheric phenomenon” which had triggered ‘induced atmospheric vibration’.”

Later, however, REN refuted that it had made these claims.

Others........

© Herald Scotland