This doesn’t seem to have gotten much notice on this side of the Atlantic, but there was a massive failure in the Spanish electrical grid Monday that caused extensive blackouts throughout Spain and Portugal and even into parts of southwestern France.
And despite fears it might have been some sort of cyberattack (for which there is absolutely no evidence, despite the inevitable rumors), the actual cause may be even more problematic in that it could be linked to the more extreme atmospheric temperature variations we can expect with greater frequency due to global warming. From the Guardian:
Red Eléctrica de España (REE), Spain’s electric network, said Spain and Portugal were hit by “el cero” – the zero. Its Portuguese counterpart, Redes Energéticas Nacionais (REN), said the outage started at 11:33am Western European summer time.
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The Portuguese prime minister, Luís Montenegro, said that the issue originated in Spain. Portugal’s REN said a “rare atmospheric phenomenon” had caused a severe imbalance in temperatures that led to the widespread shutdowns.
REN said: “Due to extreme temperature variations in the interior of Spain, there were anomalous oscillations in the very high voltage lines (400 kV), a phenomenon known as ‘induced atmospheric vibration’. These oscillations caused synchronisation failures between the electrical systems, leading to successive disturbances across the interconnected European network.”
The risks posed to electrical systems by big variations in atmospheric temperatures are well known in the industry, even if it is rare for problems to manifest on this scale.
“Due to the variation of the temperature, the parameters of the conductor change slightly,” said Taco Engelaar, managing director at Neara, a software provider to energy utilities. “It creates an imbalance in the frequency.”
Georg Zachmann, a senior fellow at Bruegel, a Brussels thinktank, said the system had suffered “cascading disconnections of power plants” – including one in France – when the frequency of the grid dropped below the European standard of 50Hz.
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Engelaar said such a widespread failure was “extremely unusual”. However, there have been previous examples. In 2003 a problem with a hydroelectric power line between Italy and Switzerland caused a huge outage across Italy for about 12 hours. A 2006 German power overload caused outages as far away as Portugal and Morocco.
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Update: It looks like the statement attributed to the Portuguese REN is now being disavowed by them from the BBC:
Portugal's grid operator REN refuted initial reports, attributed to the agency on Monday, which said the blackout was caused by a rare atmospheric event.
The message in Portuguese said that "due to extreme temperature variations in the interior or Spain, there were anomalous oscillations in the very high voltage lines (400 KV), a phenomenon known as 'induced atmospheric vibration'".
"These oscillations caused synchronisation failures between the electrical systems, leading to successive disturbances across the interconnected European network."
However, REN spokesman Bruno Silva told AFP on Tuesday that the grid operator "did not put out this statement," without giving further details.
And while Fox News was naturally quick to point a finger at renewables, particularly solar:
The massive power outage that wreaked havoc in Europe is being blamed on a pair of likely solar plant breakdowns in southwest Spain, a report said.
There does not appear to be any hard evidence yet to support such an allegation. OTOH, the “induced atmospheric vibration” hypothesis seems to have also been shot down since none of the weather data for Spain yesterday appears to be out of the ordinary. More from the BBC:
Mr Prieto said during a news conference on Tuesday that there were two "disconnection events" barely a second apart in the south-west of Spain, where there is substantial solar power generation.
One issue that the Spanish grid operator may have been referring to was when power companies identify a mismatch of supply and demand for electricity that could lead to instability, and disconnect temporarily in order to protect their systems.
However, [Spanish PM] Sánchez later said the power cut was "not a problem of excessive renewables". He said there was not a failure of coverage - meaning supply - and there was a relatively low demand for electricity that was quite normal in the days running up to the crisis.
So what exactly happened? It is unclear, especially as many systems fail in electricity supply quite frequently, not only renewables, and outages on this scale happen somewhere in the world around once a year on average.
The mismatch between supply and demand of electricity can change the frequency of the electricity grid, which is 50Hz in Europe and the UK.
If that frequency changes out of a narrow range, it could lead to damage to equipment.
"When a big company detects that the frequency is moving out of their tolerance, they can go offline to protect their equipment," said Prof Hannah Christensen at the University of Oxford.
If lots of companies do that in quick succession, it can have "cascading effects" and lead to a black-out, she added.
But when it comes to renewables, operators have very accurate short-term weather forecasts to predict when there will be a surplus of wind of solar power, so they adjust power supply accordingly, Prof Christensen said.
Renewable power has different challenges to fossil fuel energy "because of its intermittency", she said, but it is a well-known issue that is planned for.
And from the AP:
Eduardo Prieto, director of services for system operations at Spain's electricity operator, noted two steep, back-to-back “disconnection events” before Monday's blackout. He told journalists that more investigation was needed.
Spain’s meteorological agency, AEMET, said it hadn't detected any “unusual meteorological or atmospheric phenomena," and no sudden temperature fluctuations were recorded at its weather stations.
Portugal’s National Cybersecurity Center said there was no sign that the outage resulted from a cyberattack. Teresa Ribera, an executive vice president of the European Commission, also ruled out sabotage.
So it looks like the mystery will continue, at least until the various investigations are wrapped up.
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2nd Update: Not quite sure what this may mean, but the AP has an interesting new observation on the increasing instability of the Spanish electrical grid in the hours leading up to its collapse Monday:
About three hours before the outage, power quality sensors in homes in the Madrid area showed warning signs of an unstable grid — there were small fluctuations in voltage around 9:30 a.m. local time, Whisker Labs CEO Bob Marshall said Tuesday. The Maryland-based software developer has a couple dozen sensors in homes in and around Madrid, testing the technology for use in Europe for home fire prevention and grid monitoring.
Instead of normal, steady voltage, Marshall said the data shows there were oscillations whose frequency and magnitude increased over the next three hours until the grid failed. He does not know what caused the instability.
Around noon, there was a big jump in the magnitude of the fluctuations, with the voltage measured going up and down by about 15 volts every 1.5 seconds, Marshall said.
“The way I would interpret our data," Marshall said about Monday's events, "is that the grid is struggling. Something’s wrong. And it’s showing increasing signs of instability.”
