Spain is about to face the challenge of a "black start"

https://arstechnica.com/science/2025/04/why-restarting-a-power-grid-is-so-hard/

by rbanffy • 1 year ago

121 145 1 year ago

arstechnica.com

matkoniecz• 1 year ago

But according to production data it has never dropped to zero? Why it would be a black start?

It dropped from about 32GW to about 8GW

source: https://transparency.entsoe.eu/generation/r2/actualGeneratio...

though admittedly https://en.wikipedia.org/wiki/Black_start mentions that partial shutdown may be also requiring a black start?

scrlk• 1 year ago

Dropping from 32 to 8 GW usually means that an interconnected grid has fragmented into islands. If an island has a blackout, you need to black start it and resynchronise it with other islands.

joha4270• 1 year ago

But what prevents you from connecting the stopped power plants to one of those islands and then running it from there? I'm not claiming that is easy, but its not a black start.

It looks to me like the author of this article has fundamentally misunderstood what a black start is. The fact that some power generation remained both on the peninsula, but also on imported power being available means that to my understanding this cannot be classified as a "black start". A lot of overtime, a lot of careful coordination yes, a black start, no

boxed• 1 year ago

99% up now. It's pretty impressive how fast they can get the system up and running again considering how seldom they need to do these types of things.

TheOtherHobbes2• 1 year ago

Initial estimates went from "No idea" to "Could take days".

In the end it took about 12 hours to restore most of the power in two countries. There are some knock-on effects from trains being in the wrong places, but a solid result overall.

vvillena• 1 year ago

This is not correct. The REE press conference held about two hours after the start of the blackout gave an estimate of 6 to 10 hours, which was about right. Any other estimations were misinformation.

Symbiote• 1 year ago

This article was published when over half of power was already restored.

Animats2• 1 year ago

Spain is mostly back up.

Plant startup is only the first step.[1] It's load pickup.

Here is a PJM training module on load pickup during system restoration.[2] It gives a sense of how touchy the process is. Power network control has good control over generation and transmission, but limited control over load.

When load is turned on, there are transient loads with different time constants. There's a huge load for the first second as inductors, capacitors, and incandescent filaments start up. That tails off in under a second. There's a second load as motors wind up to speed. Ten seconds or so. Then there's "cold load", where everything in HVAC starts trying to get temperatures back to normal. Maybe half an hour.

There's no mention of computer control. Listening to this, you visualize people running around reading meters and throwing big switches. It's probably people looking at display boards and sending commands to remote big switches, but the concept is the same.

Botching this means voltage or frequency goes out of tolerance, protective devices shut things down, and the system operators have to start over.

More PJM training modules on related subjects.[3]

Unclear what caused this yet. Something caused enough system instability to trip protective devices, but there's no good info yet. Once everybody has a chance to compare all the logging data from different points, it will make more sense.

[1] https://pjm.adobeconnect.com/_a16103949/p622tuwooba/

[2] https://pjm.adobeconnect.com/p6e5csm81ter/

[23 https://www.pjm.com/training/training-resources

amelius• 1 year ago

Sounds like these systems are extremely vulnerable to sabotage. But adding more complexity such as distributed digitally controlled loads will not necessarily make the situation much better.

pjc502• 1 year ago

In theory maybe, but Ukraine are doing a great job of keeping their grid up in a hot war despite attacks on power infrastructure.

justlikereddit6• 1 year ago

The groundwork for the blackout will inevitably come back to a buildout and reliance of renewable sources that do not have spinning mass that can do frequency synchronization.

There are costly means to compensate for the lack of spinning baseload but actually building these devices have been neglected, to no ones surprise.

lifty• 1 year ago

Not sure why you are downvoted but this rings true to me.

Tade03• 1 year ago

Why would you need a spinning mass when you have an inverter which can produce a range of frequencies and outputs and it all boils down to coordination?

Looking at power generation reports it's the plants relying on inertia (like nuclear) which were disconnected and haven't been reconnected since:

https://app.electricitymaps.com/zone/ES/72h/hourly

tomatotomato37• 1 year ago

Unfortunately that pretty much just leaves solar panels, as wind/hydro/concentrated solar/geothermal all rely on a spinning mass moving at a mostly consistent speed, though at least hydro can black start itself relatively easily

fsh• 1 year ago

I don't see why. Battery-backed renewables should be much easier to synchronize than spinning generators.

tenthirtyam4• 1 year ago

I've always wondered why we can't just have a "master" power station transmit a 50Hz signal modulated at, say, 50MHz. Then all the other station simply sync to that, including small scale such as domestic PV etc.

Then depending on how out-of-sync a given station is with the signal, they ramp production up or down accordingly.

Is the problem here that there is inadequate or slow feedback to the supply side regarding load and therefore you'd end up with under-voltage?

atwrk2• 1 year ago

Not my area of expertise, but I think this is wrong? Modern PV inverters used in rooftop solar could easily start frequency synchronization autonomously, but are regulated to not do that autonomously in (at least) parts of the EU.

More importantly, according to the REE, PV played a mayor role in the current and successful black start.

whyever• 1 year ago

Do you mean solar energy sources? Wind turbines have plenty of "spinning mass"...

toomuchtodo2• 1 year ago

More recent renewable inverters (solar PV and wind) and battery storage both have grid forming power control support. Term of art is "synthetic inertia" and makes spinning baseload obsolete. This has been shown under real world conditions most notably in South Australia with the Tesla Megapack based Hornsdale Power Reserve, which stepped in to maintain grid inertia when a coal plant exploded in 2021. For a more robust grid, you can deploy additional battery storage that can be called upon not only for energy, but also grid support.

(also replaces the need for synchronous condensers where they would typically be sited for grid ancillary services)

https://www.abc.net.au/news/2021-05-26/queensland-blackout-c...

https://www.pscconsulting.com/australia-leans-in-on-syntheti...

https://aemo.com.au/-/media/files/initiatives/engineering-fr...

https://www.ercot.com/files/docs/2024/01/12/Tesla%20BESS%20G...

showsover4• 1 year ago

That was a fun 10 hours or so that we were without power in most of Barcelona. Some barrios had ~some~ power but most of us were without.

The one thing that surprised me is how quickly rumors started about power being out in Portugal (true), France (true to an extent), Belgium (false), and the UK (false). Walking back home from work you heard the names of Trump being mentioned as well.

It's a bit scary to personally experience how quickly people can start panicking. On the other hand the bars that had some power had a great afternoon with tons of beer being served before it got too warm :-)

consp3• 1 year ago

As long as the beer is cool, you only need CO2! Great off grid mechanism. Or N2 in case of Guinness.

xenospn• 1 year ago

I never have any cash on me. That would’ve sucked.

showsover4• 1 year ago

I spent my last 5 euros on a sandwich and a croissant to eat on the walk home. All in all a pretty decent experience.

elric2• 1 year ago

In my experience, shops you frequent will be sympathetic to that problem and will just let you come back to pay later. And I imagine that any shops that sell stuff that needs to be kept cool were especially amenable to that ...

AStonesThrow3• 1 year ago

How warm is "too warm"? I find cold beer, and cold soft drinks as well, quite repulsive. I usually try to order without ice entirely, and if I receive any bottles or cans, I permit them to come to room temp before consumption.

Refrigeration is sort of a scourge to those who enjoy food. We are so used to simply freezing our esophagus and not tasting anything! Food is kept cold because it lasts longer, not because it tastes better.

Sure, refrigeration makes restaurants and grocery stores possible. But it also presents challenges to cooking and it's very resource-intensive -- think about it -- basically everyone everywhere is always running their refrigeration -- that's a huge load on any system.

showsover4• 1 year ago

I was referring to the fact that generally people prefer cold beer, not room temp beer.

MaoSYJ• 1 year ago

Most information was spread by car radios. Rest were people asking and talking to each other.

Zealotux2• 1 year ago

I am in Barcelona too. The combination of no power and patchy internet was the perfect recipe for rumors to spread, which was fun to observe. I went for a walk since I couldn't work and saw tons of people socializing, drinking beers (more than usual), and young people playing without their phones. It'll be a special day to remember, I think.

prox2• 1 year ago

Maybe make it a yearly event, turn off all power (like Earth Day) just for the socializing aspect.

showsover4• 1 year ago

I was actually considering going for a ride on the motorcycle today if the outage lasted another day. Beautiful weather, a tank full of gasoline, and no stress about work? Sign me up!

Bad_CRC• 1 year ago

I'm close to a refinery and seeing black smoke coming out 5 minutes later of the blackout was a bit of a scare tbh.

TheOtherHobbes2• 1 year ago

Spain and Portugal had to deny a fake social viral that said power was out across most of Europe and the Russians were cutting undersea cables.

On the upside, more people at all levels are going to be more prepared if it happens again.

diggan2• 1 year ago

Most people I spoke to around Maresme area yesterday believed someone incompetent made a mistake somewhere, and that was the reason. Some people jokingly suggested cyber attack/Russian probes, but afaik no one took those seriously.

debugnik• 1 year ago

A security guard at my workplace actually told me they had "received a call" about power being out in Romania as well. I'm not sure how that one rumour spread.

IAmGraydon• 1 year ago

It's a bit scary to personally experience how quickly people can start panicking.

People have been panicking, internally, for quite some time. What happened is that the threshold to externalize that panic was dropped with this event. So this is a very real example of how people are always looking for confirmation of what they already believe, and for a relatively brief time after they receive that confirmation, can live in a reality that is not at all aligned with base reality. I find this kind of thing fascinating, and it's been happening more and more in recent years due to changing dynamics in the way we communicate.

ashoeafoot• 1 year ago

How do energy intensive processes like aluminium smelters or window glass producers preven their machines from self destruction ?

exar08154• 1 year ago

Can't answer for aluminium, but I can answer for window glass: One of our plants was threatened by massive flooding 2021, threatening the float glass oven (which doesn't float itself despite the name). It was closed off with insulation, turned off, and everyone hoped for the best and no steam explosion. In the end, only the cellars with the control equipment flooded and it could be gradually (as the control cabinets were checked and restarted) brought up again without loosing too much heat a day later.

In short: Heat Inertia of large molten bodies is massive with good insulation. If the time is too long tho, only dynamite will dismantle a solid chunk of material again.

echoangle• 1 year ago

Is the heater keeping the material liquid not enough to re-melt it again?

LunaSea• 1 year ago

Interesting! Does this mean that you could use intermittent energy sources, like solar power, to heat up the float glass oven during the day and it woul keep enough heat during the night so that it could keep running in the morning?

Mistletoe• 1 year ago

How did you find that much insulation quickly and what kind was it?

m4rtink3• 1 year ago

It works also with cold/frozen stuff - you can even store snow over the summer if needed: https://www.slf.ch/en/snow/snow-sports/schnee-und-ressourcen...

bob10292• 1 year ago

In some cases they don't have any practical ability to.

The Texas winter storm resulted in a lot of scrap at semiconductor lines due to power loss. There are industries that are completely dependent on grid power. You can't generate enough on site to back up 100% of your operation. Think about how much power one EUV source consumes.

The only reason Samsung is building additional factories in Texas is because the local utilities are effectively treating them as a critical load. The new plants are right by the ERCOT operation center and likely have access to the same cranking paths that the grid uses for black starts.

adrianN• 1 year ago

I have no idea how much power an EUV source consumes, but I’m surprised to hear that it’s more than a handful of kW. What’s the right ballpark?

_3u10• 1 year ago

Power guarantees and insurance.

They are also frequently situated close to reliable power sources such as nuclear or hydro, usually fed by more than one generating station.

A friend of mine lived close to a brick plant his power NEVER went out.

ehnto• 1 year ago

I had the same experience living near a hospital. The whole city has gone out a few times, and our grid was either still up, or is one of the first grids back up.

consp3• 1 year ago

Anecdotal example: The, now closed, Aluminium plant here was build only because the government build a nuclear plant, which is still going. There was a coal plant next to it (closed now) as a backup for when nuclear was not available. Funny thing is most people thought the coal plant was the nuclear plant when driving by since it looks more like a plant, the nuclear dome structure is kind of hidden from the road and since natural water is used as cooling no big towers are close by.

ahmedfromtunis2• 1 year ago

We had something similar happen in Tunisia in 2002. The reliance on diesel turbines meant a very long rebooting process.

As a result, the government invested heavily in installing gas turbines all over the country.

When we had another blackout event in 2018(?), it only took an hour or so to get things back again.

rightbyte• 1 year ago

Why is that? Are turbines easier to speed regulate than diesel engines?

brohee3• 1 year ago

Yes, the huge rotating mass is inherently more stable than a diesel. They key to grid stability is mostly huge rotating mass, either producing or consuming.

prox2• 1 year ago

I imagine a lot of sunshine in Tunisia (not too familiar with your country) , is there a big transition to solar?

ahmedfromtunis2• 1 year ago

Yes. Many laws have been enacted in the last 5 years to enable more solar project.

The downside is that the choice was made to focus on smaller 10-20 MW projects, with the occasional 100+ MW installation.

Hence, despite new projects entering service every couple months solar only accounts for less than 3% of electricity production nationwide.

seanalltogether• 1 year ago

If you're interested in the process of a black start

https://www.youtube.com/watch?v=uOSnQM1Zu4w

from Practical Engineering

zeristor2• 1 year ago

I am no expert, however with solar power and more grid batteries (I don’t think Spain has many grid batteries) wouldn’t it be possible to charge the batteries and use that to drive a ‘black start’.

Sounds simple, and I appreciate from experience a huge amount of prep and validation needs to be done in the background.

myself2482• 1 year ago

At an extremely abstract level, it is conceptually simple, but most inverters are designed with safeguards to prevent exactly this. They only produce power when the grid is up, and in phase with it.

Because if not sequenced and interlocked, islanding behavior can result in back-powering parts of the grid that are supposed to be disconnected and down for maintenance, or creation of desynchronized islands that then cause more damage when reconnected.

This is absolutely a problem that operators need to solve. Radio synchronization is possible, neighborhood islanding could be beneficial, etc. There are entire village-wide micro-grids in remote places where everyone's inverters do perform these functions, it just hasn't been embraced in monopoly environments yet.

For instance, relays that close isolated parts back onto the main network would need to be phase-aware, to only reconnect if it's safe to do so. You could mandate that all island-mode inverters center themselves around 50.1 or 60.1Hz in the absence of outside influence so there's certain to be phasing opportunities. Distribution networks would need more switches to provide positive isolation during maintenance. And all of these things would need huge amounts of interoperability testing. It's possible, but it has a cost.

zeristor2• 1 year ago

Thanks for the excellent insight.

I’m guessing this could be more of a thing in the future to make the grid more robust.

Didn’t Australia have a similar issue a few years back, which Tesla built a large grid battery to resolve, not just for storage but for stability.

LorenPechtel4• 1 year ago

It's not just a matter of monopolies, but risk tolerance. Only dance to the master's tune is a failsafe measure, ensuring a malfunctioning (or deliberately hacked--think of people using gay extension cords to plug generators into their house rather than the expense of a proper transfer switch) inverter doesn't electrocute a lineman.

If everyone's inverter can feed the line you have a situation where you can never be confident the line is dead and you must always work the line as if it were hot.

flysand7• 1 year ago

Oh man, this reminds me of factorio. When you miscalculate your power needs and your generators eat up the fuel that isn't being produced enough. I've had to make a bootstrapping mechanisms and power switches for some of my powerplants to ensure I can get it back up in case it goes down and I can then re-enable my factory bit by bit.

ffsm82• 1 year ago

It's even worse in satisfactory imo, because the game is build around your fabs consuming wildly varying amounts of power throughout their production cycle... And after a power loss, they'll not only need the initial burst (can be handled via batteries) but will also now all be synchronized to have their power spikes at exactly the same moment.

Dyson sphere program is the by far most forgiving in that regard. You can overdraw to something like 200% before it becomes really problematic, and even that quickly resolves itself the moment you get more power online

m4rtink3• 1 year ago

Also in Satisfactory pumps need power to run, so coal power plants quite realistically won't start without extra power (unless you have a water tower on the input).

pbmonster• 1 year ago

Unfortunately, you can't simply hand-feed 100 coal into all the Spanish thermal plants and then plop down two more to be on the safe side until you've fixed supply...

pas2• 1 year ago

but sorta you can, that's not the hard part

it's that in Factorio there are no problems with phase synchronization, and the devices, consumers, producers, so the machines don't get damaged from a lot of abrupt starting/stopping.

still, it's strange that operators and grid controllers have to do the restart manually.

cellularmitosis• 1 year ago

The real problem is when you have hundreds (or thousands) of fully discharge roboports, which will peg your power satisfaction to zero for quite some time during a black restart.

During that time, you are producing power, but none of the inserters work, none of the miners work, etc. and the distributed nature of the roboports means it isn’t straightforward to simply disconnect them.

joshstrange• 1 year ago

I'm glad I wasn't the only one nodding along with the article going "Yep, I've dealt with this in Factorio" (aside from the frequency stuff which would complicate matters for sure).

In Space Age, more than once I've needed to fly across the solar system to hand-restart a generator when I didn't have my fail-safe setup correctly. Normally I setup a SR latch to fall back to the power generators (whatever type they are) _only_ on a sub-grid when capacity falls below 20% (and alert me) since if you lose power completely, hand-feeding is the only way to fix (unless you have another air-gapped power storage/generation set up). It sucks when you hand-feed and then see all your power generation still struggling because you accidentally left in 1 copper wire to a pole outside your "air-gapped" grid. Having to slowly rebuild on Aquilo solar->nuclear->fusion is tedious, after making that mistake once I make sure I didn't have to travel back again to fix the grid... After the 2nd time it happened I finally fixed it for good.

LorenPechtel4• 1 year ago

I think they went out of their way to make a mess of the power situation. It's a PITA to build in load-shedding, almost as if they were trying to handicap solar. And not all buildings even support being disabled by control. Running my radar only during the day is good enough for keeping an eye on expansion, yet the only way to do that is isolate the radar.

everyone• 1 year ago

What caused it? Nowadays when anything like this happens in the EU, I immediately wonder if it was Russian saboteurs. They have certainly been destroying infrastructure here, eg. undersea internet and power cables.

ZeroTalent• 1 year ago

It was American saboteurs. First thing that comes to my mind /s

tenthirtyam4• 1 year ago

I was wondering if a solar flare could cause something like this. But if it had been that on this occasion, the astronomers would've been warning about it for at least 8 minutes. :-)

K0balt• 1 year ago

I can only imagine the difficulties facing technicians and engineers black starting a nation-scale grid.

I operate a microgrid facility in Hispaniola and have wonderfully cooperative users backed by a separately powered communications and control system. Even for us, a facility serving a small neighborhood and farm, a black start must be performed as a careful choreography of systems and loads…and we can just pick up a radio and tell people to turn the main breaker of their house on or off, and to leave their AC units off until we finish bringing everything up. In 12 years we’ve only had to do it twice, but even for us it’s a tedious process.

LorenPechtel4• 1 year ago

Honestly, I suspect a true blackstart would fail, too many desperate people trying to survive, keeping the people who need to get places from getting to those places. We already see the roads fail when people are fleeing wildfires.

d1sxeyes• 1 year ago

This has to be managed in a way that ensures that only other power plants get the first electrons to start moving on the grid

Oh dear.

Spain is about to face the challenge of a "black start"

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