While Sanchez insisted the specific cause of the power failure was still unclear, his Portuguese counterpart, Luis Montenegro, said there was “no indication” that a cyber attack took place.
The operator said that extreme temperature variations in the country led to “anomalous oscillations” in very high-voltage lines.
Sanchez said officials did “not yet have conclusive information on the reasons” behind the massive power cut.
University of Bath’s Professor Chenghong Gu said the “anomalous oscillations” phenomenon is “quite a normal effect”, also treating REN’s hypothesis with scepticism.
Meanwhile, Gu’s colleague at Bath University, Dr Jenny Bake,r emphasised that “we don’t know if it was just one thing” that caused the power cut or “if there were multiple things”.
What do anomalous oscillations mean in layman’s terms?
Anomalous oscillations take place when there are extreme changes in temperature, which lead to a volatility of air pressure around overhead cables.
“Power cables are quite often the cause [of blackouts], like during a storm,” he added. “They are out in the open and vulnerable.”
High-voltage pylons in Madrid (Photo: Eduardo Parra/Europa Press)
Gu said that high temperature, in particular, could cause something known as the “corona effect” on transmission lines. This effect can produce vibrations in conductors, which connect power lines to pylons.
“The stability of power systems is very sensitive to these [vibrations]… In the worst case, system frequency could drop too low, and customers must be cut off to re-balance the supply and demand.”
Baker, meanwhile, said grid operators are “trying to keep to a very small margin of frequencies, around 50 Hz”. If the frequency drops too low, she explains, then the operator has to disconnect customers.
Gu described a “domino effect” whereby, if the grid’s frequency is outside the desired 50 Hz, then a localised customer base will be cut off from the grid, to bring the frequency back to the right level.
A restaurant has no lights on during a power outage in Lisbon, Portugal (Photo: Adri Salido/Getty Images)
“The power grids in EU countries are interconnected,” he added. “It means all grids are synchronised. If there are any failures somewhere in one part of the system, the consequence can immediately propagate to other regions.
Why was there no fallback?
Interconnected grids, like the ones in Spain and Portugal, should, in theory, mean there are reliable backup solutions.
While there is no official explanation for why there was not a sufficient fallback system in place, he said it could be explained by an “operational error” or backup systems being “under maintenance”.
Read Next
square MINING AnalysisThe dying coal town that reveals Trump's lies about reviving mining
Read More“We have two mechanisms to alleviate the impact of such events. One is the capacity market, which is launching this summer in Spain, but we have had it since 2012.
“The cause may still be there, but you could generate sufficient power… It reduces the chance right after the event [of a blackout] of not having enough energy.”
He also said the UK has access to a “black start process”, which helps restore electrical power stations without relying on external electrical power from the grid to recover.
Read More Details
Finally We wish PressBee provided you with enough information of ( The biggest questions on Iberian blackout answered by experts )
Also on site :