Yep. It’s no different than sizing a diesel generator to handle block loading. The generator needs to handle inrush currents from motors, etc or the voltage and frequency go haywire and you drop load. Somebody forgot to tell the policy makers (politicians) about science, physics and common sense. Play stupid games win stupid prizes.
Major power grid issues in Portugal, Spain and parts of France
- Thread starter alarmguy
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Yep. It’s no different than sizing a diesel generator to handle block loading. The generator needs to handle inrush currents from motors, etc or the voltage and frequency go haywire and you drop load. Somebody forgot to tell the policy makers (politicians) about science, physics and common sense. Play stupid games win stupid prizes.
The whole point of the test was if a nefarious entity managed to sneak into the software/control systems the damage that could be easily caused.
If someone hacked into the control system of a steam plant you would have much more damage.
It was given as an example of why they don't just 'turn the power back on'. Because it is not just that simple.
This is an even better overview of large scale power systems.
and
This one goes over inertia and why renewables are harder to integrate.
and
This one goes over inertia and why renewables are harder to integrate.
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You used the word " easily " and I disagree . A steam plant is probably the most difficult . These plants are not autonomous . It takes more than software to operate one . And automatic controls can be disabled with a selector switch by a CRO .
First part of the dog and pony show...they ran on 100% renewables on day.
That particular day, a little past 11 in the morning there was sufficient generation from renewables TO HAVE run the country...while that lasted, a matter of minutes.
That particular day, they also had 2,767MW of nukes, 2,038MW of combined cycle GT, 1,434MW of cogen, 284MW of diesel, 231MW of Coal, and 122MW of "steam turbine"...6,876MW of traditional pwer.
All up generation in that period was 39,000MW, take off 7,000 of regular process, leaves 32,000MW of renewables...for a demand of 29,481MW....so YES they could have run on renewables...for a little while, but they also had lots of traditiional power to provide the grid for them...
It's the same three card trick South Australia pull with 100% renewables...while burning gas to keep the grid.
That particular day, a little past 11 in the morning there was sufficient generation from renewables TO HAVE run the country...while that lasted, a matter of minutes.
That particular day, they also had 2,767MW of nukes, 2,038MW of combined cycle GT, 1,434MW of cogen, 284MW of diesel, 231MW of Coal, and 122MW of "steam turbine"...6,876MW of traditional pwer.
All up generation in that period was 39,000MW, take off 7,000 of regular process, leaves 32,000MW of renewables...for a demand of 29,481MW....so YES they could have run on renewables...for a little while, but they also had lots of traditiional power to provide the grid for them...
It's the same three card trick South Australia pull with 100% renewables...while burning gas to keep the grid.
As to the future, and I'll refer to Oz....
The grid controllers have an event, and a mandated 30 minutes to recover. A unit traips, a pot line trips, the system bounces and they have 30 minutes to sort it all out.
Historically they had 4 or 5 handfuls of people/generators/switchyards to call and issue directions.
Now they've got hundreds...and some of them are call centres in remote companies, running plant remotely, and they can't get all of them...sometimes they just have to open the breaker.
With thousands of MW of rooftop solar, they are struggling...chart below is a few years ago...showing rooftop solar, that they can't control, and renewables, and coal. That particular day, they could have claimed capability to Run Oz on renewables (red dotted line) but they couldn't as they needed traditional resouces either side of that....So they had to direct a heap of solar and wind offline, so the traditional generators could run to min gen, and be availblae for the peak....that's the gap between the solid red and the dotted. I've superimposed the little blocks which is the current battery storage, to demonstrate how much would be needed just to move the curtailed load to a better time, and the impact storage has.
The grid controllers have an event, and a mandated 30 minutes to recover. A unit traips, a pot line trips, the system bounces and they have 30 minutes to sort it all out.
Historically they had 4 or 5 handfuls of people/generators/switchyards to call and issue directions.
Now they've got hundreds...and some of them are call centres in remote companies, running plant remotely, and they can't get all of them...sometimes they just have to open the breaker.
With thousands of MW of rooftop solar, they are struggling...chart below is a few years ago...showing rooftop solar, that they can't control, and renewables, and coal. That particular day, they could have claimed capability to Run Oz on renewables (red dotted line) but they couldn't as they needed traditional resouces either side of that....So they had to direct a heap of solar and wind offline, so the traditional generators could run to min gen, and be availblae for the peak....that's the gap between the solid red and the dotted. I've superimposed the little blocks which is the current battery storage, to demonstrate how much would be needed just to move the curtailed load to a better time, and the impact storage has.
Two charts below...the energy mix just before, and the energy mix over time, including the trip.
edit...there was less then 30% synchronous machines with governors, the rest basically inverters providing power and "following" the frequency of the grid.
edit...there was less then 30% synchronous machines with governors, the rest basically inverters providing power and "following" the frequency of the grid.
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The system black started with a big loss of generation (somewhere), and while the system was reeling another within 3.5 seconds...then some more and 18GW came out of the system. Overloaded the France interconnector (would have done with DC anyway), and the whole lot went down.
the whole grid has some islands, so there were still places generating and consuming...
The thermal flux creating an oscillation in the grid isn't the cause...IMO it was a technical person explaining to a politician in spanish translated to english...didn't haper, and meteorological data confirms that it didn't happen even if it could.
It's reported that they were having voltage swings a long time before it, so stability prior is questionable.
But inveters respond to things hundreds of times a second, and if they detect variations between cycles, they can respond...that's my fear with modern grid. Turbines and generators have inertia, they are saying that inverters have "synthetic" inertia...just means they throw more watts at it really.
the whole grid has some islands, so there were still places generating and consuming...
The thermal flux creating an oscillation in the grid isn't the cause...IMO it was a technical person explaining to a politician in spanish translated to english...didn't haper, and meteorological data confirms that it didn't happen even if it could.
It's reported that they were having voltage swings a long time before it, so stability prior is questionable.
But inveters respond to things hundreds of times a second, and if they detect variations between cycles, they can respond...that's my fear with modern grid. Turbines and generators have inertia, they are saying that inverters have "synthetic" inertia...just means they throw more watts at it really.
The upside they’ll learn and move on to better handle this.
There’s inertia in the generation equipment. Then there’s inertia in the equipment lifetime, meaning if they’ve “learned” they need a different inverter design to make the grid more stable there’s still tens of thousands of existing inverters online that aren’t going anywhere soon.
It’s not like software where you say “whoops, push a patch”.
It’s not like software where you say “whoops, push a patch”.
Davidson covered it 3 days ago
Overkill, when you discuss frequency, are you talking about the change or deviation from the 50 or 60 Hz? Or, is there a different frequency due to electrical mass in the conductor/power line? I am visualizing something like water-hammering in plumbing pipes at home where one can hear a pipe banging against a hard object in the walls because the pipe is not secured well and one shuts the water off quickly.
Very interesting topic. Thanks for sharing.
OVERKILL
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Yes, we are talking about deviation (more like pulling away) from the 50 or 60Hz synchronization of the grid. The oscillations my friend mentioned in the post of his I quoted are that. Eventually, you get enough of this, or the swings are large enough, and the protection equipment steps in to save equipment like transformers and that disconnect collapses the grid.
Here's a good read on this subject, shared by the same friend:
https://www.nerc.com/comm/RSTC_Reli...ment_NERC_Balancing_and_Frequency_Control.pdf
Thanks Overkill. This is an interesting topic.
OVERKILL
$100 Site Donor 2021
I heard! That should be fun!
Congratulations to Spain and Portugal on achieving net zero before 2050.
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$100 Site Donor 2021
Former head of the Spanish electricity grid penned an article:
https://cincodias.elpais.com/opinion/2025-05-08/se-pudo-hacer-mas-para-evitar-el-apagon.html
Some translated quotes:
The Spanish electricity system, in line with the European one, has undergone a total revolution in just a few years by closing coal-fired power plants, limiting gas plants and betting, with a lot of public subsidy behind it, especially wind and photovoltaic plants. This has had two impacts on the operation of the system and its operations: the generation points connected to the transmission grid have multiplied, as well as their geographical distribution and, secondly, a system designed to manage synchronous energies has had to be adapted to integrate, in a short time, a very significant volume of non-synchronous energies whose physical characteristics (voltage and frequency) are very different from the point of view of balance of the network. I am not discovering anything new, nothing that was not known from the beginning and warned to those who have the responsibility of approving energy policy.
All of us who supported the renewables option knew and warned of its implication on the guarantee of supply: it required important changes in the grids (more nodes and smarter grids), in the criteria that govern the system's protection standards and, also, to maintain sufficient synchronous backup energy so that, properly combined by the operator with renewables, stability and supply will be guaranteed. As the objective was to reduce CO2 emissions, many of us assumed that nuclear would be retained among the backup technologies because it was considered clean by the Commission. All this, starting with the obvious: regulating for wind and photovoltaic energies the obligation to equip themselves with technology (which exists) that allows them to adequately regulate essential parameters for the safe operation of the system (such as voltage).
The first surprise was when the draft PNIEC opted for a timetable for the closure of nuclear plants, without any explanation and assuming a risk as high as it was unnecessary in terms of supply, because the renewables painted were far from being assured. The second was the aforementioned cut in investments in networks when the ministry approved the mandatory planning. The third, we are learning now, when it is published that the different regulatory proposals that REE has presented to make wind and photovoltaic inverters mandatory, sleep the sleep of the righteous in the drawers of the ministry and the CNMC that have not considered it urgent during these years. The last is the delay in the essential adaptation of the general criteria for the protection of the network to the new situation of the mix. In addition to that, the delays in the regulation of storage, the need to increase interconnections and establish the so-called payments for capacity as a complement to the promotion of renewables.
No one can say that they did not know that the massive integration of renewables (a laudable objective supported by almost everyone) required significant changes in regulations, in investment in networks and in the procedures of the system and the operator if they wanted to continue guaranteeing supply and reducing the risks of a blackout. I can attest that, at least, REE's technicians have been insistent in this regard from the beginning. The most recent report points out that "the massive entry of renewable generation, mostly based on power electronics, has led to a change when it comes to establishing equipment requirements for the protection system". And we can already say that, in all this, in this essential accompaniment to the growth of renewables, the slowness of action by those who correspond has been excessive. I am not saying that if everything required had been done, the blackout of the 28th would not have occurred. I don't know. Let's wait for the official report which, I hope, will not take long. But I'm sure that the chances of having instabilities, voltage fluctuations and blackouts, as we have had, would have been greatly reduced.
This has many statements that align with both what my former grid operator friend (now NERC reliability assessor in his retirement) and @Shannow have said on the issue.
https://cincodias.elpais.com/opinion/2025-05-08/se-pudo-hacer-mas-para-evitar-el-apagon.html
Some translated quotes:
The Spanish electricity system, in line with the European one, has undergone a total revolution in just a few years by closing coal-fired power plants, limiting gas plants and betting, with a lot of public subsidy behind it, especially wind and photovoltaic plants. This has had two impacts on the operation of the system and its operations: the generation points connected to the transmission grid have multiplied, as well as their geographical distribution and, secondly, a system designed to manage synchronous energies has had to be adapted to integrate, in a short time, a very significant volume of non-synchronous energies whose physical characteristics (voltage and frequency) are very different from the point of view of balance of the network. I am not discovering anything new, nothing that was not known from the beginning and warned to those who have the responsibility of approving energy policy.
All of us who supported the renewables option knew and warned of its implication on the guarantee of supply: it required important changes in the grids (more nodes and smarter grids), in the criteria that govern the system's protection standards and, also, to maintain sufficient synchronous backup energy so that, properly combined by the operator with renewables, stability and supply will be guaranteed. As the objective was to reduce CO2 emissions, many of us assumed that nuclear would be retained among the backup technologies because it was considered clean by the Commission. All this, starting with the obvious: regulating for wind and photovoltaic energies the obligation to equip themselves with technology (which exists) that allows them to adequately regulate essential parameters for the safe operation of the system (such as voltage).
The first surprise was when the draft PNIEC opted for a timetable for the closure of nuclear plants, without any explanation and assuming a risk as high as it was unnecessary in terms of supply, because the renewables painted were far from being assured. The second was the aforementioned cut in investments in networks when the ministry approved the mandatory planning. The third, we are learning now, when it is published that the different regulatory proposals that REE has presented to make wind and photovoltaic inverters mandatory, sleep the sleep of the righteous in the drawers of the ministry and the CNMC that have not considered it urgent during these years. The last is the delay in the essential adaptation of the general criteria for the protection of the network to the new situation of the mix. In addition to that, the delays in the regulation of storage, the need to increase interconnections and establish the so-called payments for capacity as a complement to the promotion of renewables.
No one can say that they did not know that the massive integration of renewables (a laudable objective supported by almost everyone) required significant changes in regulations, in investment in networks and in the procedures of the system and the operator if they wanted to continue guaranteeing supply and reducing the risks of a blackout. I can attest that, at least, REE's technicians have been insistent in this regard from the beginning. The most recent report points out that "the massive entry of renewable generation, mostly based on power electronics, has led to a change when it comes to establishing equipment requirements for the protection system". And we can already say that, in all this, in this essential accompaniment to the growth of renewables, the slowness of action by those who correspond has been excessive. I am not saying that if everything required had been done, the blackout of the 28th would not have occurred. I don't know. Let's wait for the official report which, I hope, will not take long. But I'm sure that the chances of having instabilities, voltage fluctuations and blackouts, as we have had, would have been greatly reduced.
This has many statements that align with both what my former grid operator friend (now NERC reliability assessor in his retirement) and @Shannow have said on the issue.
OVERKILL
$100 Site Donor 2021
More on the Spain blackout from Chris Keefer on X (Decouple Podcast):
To @BurggrabenH this blackout was a warning shot. “The hellbrise made it all possible,” he explains, coining a term that may soon enter our energy lexicon alongside its counterpart “dunkelflaute.”
Dunkelflaute is German for “dark doldrums,” when neither wind nor sun are around to generate power.
Hellbrise, in contrast, means “bright breeze.” It sounds cheerful enough but is proving even more problematic for grid operators. It creates not too little but too much power. It can't be easily controlled, argues Stahel, especially when it comes from thousands of distributed solar panels beyond direct operator control.
The modern grid walks a knife’s edge. Every second, supply must perfectly match demand to maintain a steady frequency. This electrical heartbeat must stay near 50 Hz in Europe. When that frequency strays too far in either direction, equipment overheats, protection systems trigger, and cascading failures can arrive in seconds. What made the Spanish blackout remarkable wasn't the initial problem, but how quickly it spread: 15 gigawatts of solar generation collapsed in just 1.5 seconds—roughly the time since you read “1.5 seconds.” Too fast for a human to do much of anything.
In a moment of post-blackout clarity, Spanish grid operators immediately reduced solar's share from 55% to 31% of generation, bringing conventional resources back online.
Beyond the technical failures lies a market failure. Current electricity markets reward the cheapest generators first, pushing nuclear plants into unprofitable territory when renewables flood the grid with zero marginal cost power. The inertia and stability services that nuclear and other conventional plants provide go unvalued.
The path forward requires honesty about tradeoffs. Stahel suggests we've forgotten the critical nature of electricity: “If electricity breaks down… after three days we become zombies. We literally kill each other for food or for life support.” This is hardly hyperbole—in Spain, supermarket fights broke out less than two hours after the blackout began.
https://x.com/Dr_Keefer/status/1922289172334760364/photo/1
To @BurggrabenH this blackout was a warning shot. “The hellbrise made it all possible,” he explains, coining a term that may soon enter our energy lexicon alongside its counterpart “dunkelflaute.”
Dunkelflaute is German for “dark doldrums,” when neither wind nor sun are around to generate power.
Hellbrise, in contrast, means “bright breeze.” It sounds cheerful enough but is proving even more problematic for grid operators. It creates not too little but too much power. It can't be easily controlled, argues Stahel, especially when it comes from thousands of distributed solar panels beyond direct operator control.
The modern grid walks a knife’s edge. Every second, supply must perfectly match demand to maintain a steady frequency. This electrical heartbeat must stay near 50 Hz in Europe. When that frequency strays too far in either direction, equipment overheats, protection systems trigger, and cascading failures can arrive in seconds. What made the Spanish blackout remarkable wasn't the initial problem, but how quickly it spread: 15 gigawatts of solar generation collapsed in just 1.5 seconds—roughly the time since you read “1.5 seconds.” Too fast for a human to do much of anything.
In a moment of post-blackout clarity, Spanish grid operators immediately reduced solar's share from 55% to 31% of generation, bringing conventional resources back online.
Beyond the technical failures lies a market failure. Current electricity markets reward the cheapest generators first, pushing nuclear plants into unprofitable territory when renewables flood the grid with zero marginal cost power. The inertia and stability services that nuclear and other conventional plants provide go unvalued.
The path forward requires honesty about tradeoffs. Stahel suggests we've forgotten the critical nature of electricity: “If electricity breaks down… after three days we become zombies. We literally kill each other for food or for life support.” This is hardly hyperbole—in Spain, supermarket fights broke out less than two hours after the blackout began.
https://x.com/Dr_Keefer/status/1922289172334760364/photo/1
Basically the grid acted (as it does) like a torsion bar....the synchronous machines we clearly not capable of damping that much energy.
I'm questioning how grid following inverters respond to stuff like that....I'm also questioning whether grid forming inverters can introduce another frequency.
I'm questioning how grid following inverters respond to stuff like that....I'm also questioning whether grid forming inverters can introduce another frequency.
