The problem the OP is talking about is renewable islanding.
To be clear, this is a renewable problem, not a rules problem.
The problem, put simply, is that renewables don't want to be reactive power sources. It requires additional equipment to properly determine what the frequency of the grid should be (some rely on flywheels, for example) and getting it wrong can be disastrous for the grid and equipment. Effectively, if renewables get it wrong they become a load on the grid rather than a reactive power source. Compounding an active problem.
So, what renewables do instead is follow the voltage wave. If the frequency drops, they cut power to avoid causing damage to the grid and other power suppliers. The thing more traditional spinning disk power suppliers will do is simply power through the down voltage. The disks have momentum which means even if they wanted to, they could just stop producing power. This somewhat self corrects a large reactive power surge.
Grids do not like doing this. This is why they'll charge more to industrial power users that add highly inductive loads (think electric motors, like a saw). They'll even incentivize having these businesses install capacitor banks to avoid adding inductive loads.
The solution is rules, but rules renewable producers have to follow. That's mandatory islanding equipment installs rather than just shutting down power.
scblock · 7h ago
Renewables can absolutely provide and consume reactive power through the use of power electronics equipment incorporated into the inverters. All modern utility-scale wind and solar power plants use this type of equipment, and most interconnection requirements in the US require significant reactive power capability as part of the interconnection process. This may require additional reactive power capabilities such as capacitor banks, DVAR units, or reactors at the project substation.
This means if grid voltage drops they will provide VARs to increase voltage, and vice versa. They can similarly react to shifts in grid frequency. Only after they reach certain power factor, voltage, or frequency limits will they disconnect from the grid, similar to other generators.
If in spain renewable energy projects were somehow exempted from needing to provide a wide range of power factor capability then yes this would be a rules problem.
They charge more for inductive loads because of low power factors and significant VAR consumption yes, though you can also do power factor correction on induction motors. And though most wind turbines use induction generators, they are designed to be able to supply power at unity power factor and through a large power factor range.
Also, islanding means operating as a standalone grid, which does not happen when the generators shut down, and systems are designed to shut down after a certain number of cycles without grid. This does not sound like islanding at all.
cogman10 · 7h ago
Good comment and I do not disagree. I wasn't aware that the US had significant reactive power requirements (I'm guessing for utility scale solar).
> And though most wind turbines use induction generators, they are designed to be able to supply power at unity power factor and through a large power factor range.
Correct me if I'm wrong, but I was under the impression that wind turbines did an AC->DC->AC dance to ultimately get the right power factors and frequencies.
scblock · 7h ago
That is correct. There are no modern utility scale turbines that are directly coupled to the grid. This was at least initially to allow for variable rotor speed at a constant grid frequency.
Some use doubly-fed induction generators which take about 1/3 of the power through an inverter at variable frequency back through the rotor to create stable 50 or 60 Hz output (Type 3 machines), while others do full scale conversion (Type 4 machines)[1].
FERC 827[2] details the power factor requirements in the US for non-spinning (mostly renewable) generators, most easily summarized as power factors from 0.95 lagging to 0.95 leading at the high side of the transformer in the project substation.
> I wasn't aware that the US had significant reactive power requirements (I'm guessing for utility scale solar).
Yes, you were. The article says:
> Yet “other operators, such as in the U.S., require or reward grid participants for helping balance this reactive power,” Lara says. Spain could do that, too, given its commitment to expanding the role of renewable, and therefore distributed, power.
xenadu02 · 7h ago
Rooftop Solar in the US has had such requirements for a long time. More recent systems in CA like mine (IIRC starting in 2018) require an active connection to the grid operator so the operator can override the default exceedance values to permit larger excursions for longer to avoid a cascade where grid instability causes lots of solar capacity to trip, causing further instability, leading to collapse.
They can also command solar to stop providing power to the grid if there is an excess in the other direction though legally there is a limit to how often they can do that and for how much total time.
jauntywundrkind · 7h ago
> The problem, put simply, is that renewables don't want to be reactive power sources. It requires additional equipment to properly determine what the frequency of the grid should be (some rely on flywheels, for example) and getting it wrong can be disastrous for the grid and equipment.
I sort of agree with you, but the motive I'm not sure I agree with. "renewables don't want to be reactive" doesn't feel right.
The challenge here is technical/control. There probably is no heuristic you can make at your home to know how to nudge the power phase/reactivity, or to supply less.
I think renewables probably could be enormously helpful and probably wouldn't mind, wouldn't be very hard for them to help shape the power!! They are vastly more flexible at inverting power than any other power source, are very readily programmable.
But most renewables don't have the whole grid view, would be guessing wildly based on local conditions that don't provide adequate information to show what's really happening to the power network.
I hope over time the idea of the Virtual Power Plant related infrastructure starts building good protocols, starts being able to ask for what it wants from who it wants, providing some of the coordination necessary to take advantage of the enormous flexibility that renewable power, with its digitally dictated power delivery, bring. I think renewables would be amazing and happy to help here, if there were better information flow.
cogman10 · 7h ago
> But most renewables don't have the whole grid view, would be guessing wildly based on local conditions that don't provide adequate information to show what's really happening to the power network.
This is how other power generators are working. You don't really need a whole grid view either to make these decisions based on your local interconnect. You do, however, need either some pretty fast electronics and inverters or a reliable system that responds correctly to frequency demands. Making it smarter isn't entirely helpful.
Grid connected inverter software has to follow mandated rules defined by the grid managing organisation, otherwise it's simply illegal to connect it to the grid.
So if there are issues related to the behaviour of the grid connected inverters, except for bugs, mismanagement or hardware failure, it's 100% the fault of the grid managing organisation.
Inverters can provide grid stability if and only if the grid managing organisations allows it by putting in place rules and market mechanisms for it.
kmitz · 6h ago
I think you are mixing up different concepts.
Power impacts frequency, reactive power impacts voltage.
It doesn't make sense to "cut power when frequency drops".
eldaisfish · 6h ago
I can confirm. The parent comment here mixes several concepts and is mostly incorrect.
eldaisfish · 6h ago
This is not an islanding problem.
The vast majority of wind turbines and every solar PV inverter can provide reactive power. They are mandated to provide this in many parts of the US and Australia.
Frequency and reactive power are not directly connected. Active power influences frequency, reactive power affects voltage.
Reactive power does not change whether a renewable generator is a load or a generator.
Low-voltage ride through, including reactive power requirements have been in place for over a decade now, at least in Europe.
The comment above demonstrates a shocking level of misunderstanding.
diggan · 8h ago
> the four official investigations into the cause haven’t yet released their conclusions, and people are still waiting to know the causes of the blackout.
Officials themselves have said it'll take months (https://elperiodicodelaenergia.com/el-gobierno-estima-que-su...) before the report is done, basically saying it won't be until sometime between July and October that we'll know what happened. I kind of feel like there isn't much point in speculation about the reasons until the people who sit on all the data can actually give some definitive conclusions.
A bit like guessing why Google/CloudFlare/Amazon went down this time, five minutes into the downtime, and arguing about why it is/isn't DNS/BGP.
jakub_g · 5h ago
Relevant parallel thread:
"Miscalculation by Spanish power grid operator REE contributed to massive blackout, report finds"
They changed the mix since then to have more presence of combined cycle, that should be a hint.
MaxHoppersGhost · 7h ago
0% chance European investigators find renewables at fault.
cogman10 · 7h ago
I see no reason why they wouldn't. Nobody wants an unstable grid and if it's renewables that ultimately killed the grid they'll want to know exactly why and how to prevent it in the future.
There are known problems with renewables, but there's also solutions that can be retrofit onto renewables to avoid those problems. Renewable power suppliers won't like those costs because it will cost money.
ErneX · 7h ago
The Spanish government blamed nuclear since the day of the blackout. Red Eléctrica has a government majority stake and they appointed its director (someone with zero energy sector experience by the way) and seeing how they cover every corruption scandal lately I wouldn't be surprised they try to sweep this under the rug as well.
Hopefully the EU does a decent investigation though.
diggan · 5h ago
There is still no official explanation so lets not say that the government has "blamed" anything (yet), we have to wait for the official to know what they "blame".
ErneX · 5h ago
President Sanchez: “These plants, far from being a solution, have been a problem”
Outright lie specially considering we got power back in huge part thanks to France nuclear power.
diggan · 5h ago
I'm not Sanchez fanboy by any measure, but are you sure you understand that article correctly? He seems to be talking about Spanish nuclear plants, not the French ones...
ErneX · 4h ago
Of course I understand. I also heard him live on my battery powered radio the day of the blackout once he came out to speak for the 1st time at around 5pm, almost 6 hours after the blackout started to say basically nothing.
diggan · 3h ago
> Of course I understand
Ok, so why bring up French nuclear power then?
> after the blackout started to say basically nothing
Yeah, I mean typical governments, "basically nothing" is their forte.
I've also been listening to what they're saying (or not) since the blackout happened too, and the only concrete thing they're saying is "wait for the full report", I'm not sure how anyone could understand it any differently.
To be clear, this is a renewable problem, not a rules problem.
The problem, put simply, is that renewables don't want to be reactive power sources. It requires additional equipment to properly determine what the frequency of the grid should be (some rely on flywheels, for example) and getting it wrong can be disastrous for the grid and equipment. Effectively, if renewables get it wrong they become a load on the grid rather than a reactive power source. Compounding an active problem.
So, what renewables do instead is follow the voltage wave. If the frequency drops, they cut power to avoid causing damage to the grid and other power suppliers. The thing more traditional spinning disk power suppliers will do is simply power through the down voltage. The disks have momentum which means even if they wanted to, they could just stop producing power. This somewhat self corrects a large reactive power surge.
Grids do not like doing this. This is why they'll charge more to industrial power users that add highly inductive loads (think electric motors, like a saw). They'll even incentivize having these businesses install capacitor banks to avoid adding inductive loads.
The solution is rules, but rules renewable producers have to follow. That's mandatory islanding equipment installs rather than just shutting down power.
This means if grid voltage drops they will provide VARs to increase voltage, and vice versa. They can similarly react to shifts in grid frequency. Only after they reach certain power factor, voltage, or frequency limits will they disconnect from the grid, similar to other generators.
If in spain renewable energy projects were somehow exempted from needing to provide a wide range of power factor capability then yes this would be a rules problem.
They charge more for inductive loads because of low power factors and significant VAR consumption yes, though you can also do power factor correction on induction motors. And though most wind turbines use induction generators, they are designed to be able to supply power at unity power factor and through a large power factor range.
Also, islanding means operating as a standalone grid, which does not happen when the generators shut down, and systems are designed to shut down after a certain number of cycles without grid. This does not sound like islanding at all.
> And though most wind turbines use induction generators, they are designed to be able to supply power at unity power factor and through a large power factor range.
Correct me if I'm wrong, but I was under the impression that wind turbines did an AC->DC->AC dance to ultimately get the right power factors and frequencies.
Some use doubly-fed induction generators which take about 1/3 of the power through an inverter at variable frequency back through the rotor to create stable 50 or 60 Hz output (Type 3 machines), while others do full scale conversion (Type 4 machines)[1].
FERC 827[2] details the power factor requirements in the US for non-spinning (mostly renewable) generators, most easily summarized as power factors from 0.95 lagging to 0.95 leading at the high side of the transformer in the project substation.
[1]: https://www.esig.energy/wiki-main-page/wind-turbine-technolo...
[2]: https://www.ferc.gov/sites/default/files/2020-06/RM16-1-000....
Yes, you were. The article says:
> Yet “other operators, such as in the U.S., require or reward grid participants for helping balance this reactive power,” Lara says. Spain could do that, too, given its commitment to expanding the role of renewable, and therefore distributed, power.
They can also command solar to stop providing power to the grid if there is an excess in the other direction though legally there is a limit to how often they can do that and for how much total time.
I sort of agree with you, but the motive I'm not sure I agree with. "renewables don't want to be reactive" doesn't feel right.
The challenge here is technical/control. There probably is no heuristic you can make at your home to know how to nudge the power phase/reactivity, or to supply less.
I think renewables probably could be enormously helpful and probably wouldn't mind, wouldn't be very hard for them to help shape the power!! They are vastly more flexible at inverting power than any other power source, are very readily programmable.
But most renewables don't have the whole grid view, would be guessing wildly based on local conditions that don't provide adequate information to show what's really happening to the power network.
I hope over time the idea of the Virtual Power Plant related infrastructure starts building good protocols, starts being able to ask for what it wants from who it wants, providing some of the coordination necessary to take advantage of the enormous flexibility that renewable power, with its digitally dictated power delivery, bring. I think renewables would be amazing and happy to help here, if there were better information flow.
This is how other power generators are working. You don't really need a whole grid view either to make these decisions based on your local interconnect. You do, however, need either some pretty fast electronics and inverters or a reliable system that responds correctly to frequency demands. Making it smarter isn't entirely helpful.
I beg to differ.
The only difference between your run of mill solar/battery inverter and a grid forming inverter is ... software. Source NREL: https://docs.nrel.gov/docs/fy24osti/90256.pdf
Grid connected inverter software has to follow mandated rules defined by the grid managing organisation, otherwise it's simply illegal to connect it to the grid.
So if there are issues related to the behaviour of the grid connected inverters, except for bugs, mismanagement or hardware failure, it's 100% the fault of the grid managing organisation.
Inverters can provide grid stability if and only if the grid managing organisations allows it by putting in place rules and market mechanisms for it.
Power impacts frequency, reactive power impacts voltage. It doesn't make sense to "cut power when frequency drops".
The vast majority of wind turbines and every solar PV inverter can provide reactive power. They are mandated to provide this in many parts of the US and Australia.
Frequency and reactive power are not directly connected. Active power influences frequency, reactive power affects voltage.
Reactive power does not change whether a renewable generator is a load or a generator.
Low-voltage ride through, including reactive power requirements have been in place for over a decade now, at least in Europe.
The comment above demonstrates a shocking level of misunderstanding.
Officials themselves have said it'll take months (https://elperiodicodelaenergia.com/el-gobierno-estima-que-su...) before the report is done, basically saying it won't be until sometime between July and October that we'll know what happened. I kind of feel like there isn't much point in speculation about the reasons until the people who sit on all the data can actually give some definitive conclusions.
A bit like guessing why Google/CloudFlare/Amazon went down this time, five minutes into the downtime, and arguing about why it is/isn't DNS/BGP.
"Miscalculation by Spanish power grid operator REE contributed to massive blackout, report finds"
https://news.ycombinator.com/item?id=44301186
There are known problems with renewables, but there's also solutions that can be retrofit onto renewables to avoid those problems. Renewable power suppliers won't like those costs because it will cost money.
Hopefully the EU does a decent investigation though.
https://www.eldiario.es/economia/sanchez-manda-mensaje-claro...
Outright lie specially considering we got power back in huge part thanks to France nuclear power.
Ok, so why bring up French nuclear power then?
> after the blackout started to say basically nothing
Yeah, I mean typical governments, "basically nothing" is their forte.
I've also been listening to what they're saying (or not) since the blackout happened too, and the only concrete thing they're saying is "wait for the full report", I'm not sure how anyone could understand it any differently.