What caused Spain's mass blackout?

You thought your Monday was tough? Spare a thought for the 50-70 million across Portugal and Spain who, at noon, crashed face-first into a mass blackout — phones down, traffic lights out, passengers stuck on trains, kids stranded on rollercoasters, toilet paper panic-buying (always the TP), and government pleas to stay home. For up to 24 hours!

So, er, what happened?

Prime Minister Sánchez urged folks not to speculate, but the blame game kicked in more quickly than the power:

• Sánchez himself quickly threw shade at the European grid system

• Others feared sabotage given Russia’s hybrid war on Ukraine’s backers, and

• Still others blamed an over-reliance on renewable energy.

But Portugal’s grid operator has now ruled out a cyberattack, instead pointing the finger at a “rare atmospheric phenomenon” of shifting temperatures; Spain’s operator has flagged that grid vibrations played a role; and a European energy industry body has (echoing Sánchez above) blamed “an interconnector between France and Spain”.

So… which was it? The most plausible theory we’ve seen kinda blends the above:

• Extreme temperature variations hit Spain’s interior

• That caused wild oscillations along Spain’s high-voltage lines

• This instability spread to Portugal via their integrated grid

• That all caused ‘synchronisation failures’ with the broader European network

• Various power assets then automatically disconnected to avoid damage, leading to a mass blackout and sudden nationwide urge to buy toilet paper.

So it looks like an extremely rare weather event was the initial trigger, but there’s now a fierce and nerdy debate on whether other factors then exacerbated the instability:

• Renewables? Both Spain and Portugal have high renewable penetration, implying a weather-dependent supply that could stress grid stability if not handled properly

• Inertia? Renewables can provide less grid inertia (stability from rotating generators), which could mean less resilience and worse cascade effects, and

• Interconnection stress? Renewables can lean on interconnectors to balance supply, which could’ve contributed to the sudden failure of the Spain-France link.

But others note that a) we’re still gathering the facts, b) the grid operators know how to manage renewable variability, c) the scale of the outage (15GW lost in seconds) suggests a systemic grid failure, similar to d) Italy’s mass outage of 2003, which hit a dirtier grid.

Anyway, based on all this initial and incomplete data, wild weather appears to have been an immediate trigger, and neighbours like France and Morocco appear to have been key to helping get local systems back online.