This is why the common trope of "The grid can't function without the inertia from big heavy generators!!" detracting the rise of renewables is invalid. Synthetic grid strength has been available for a century.
Today the research focuses on "Grid forming inverters". Taking the same principle as powering a home in island mode and stretching it to the entire grid allowing non-synchronous generators to provide the system strength.
Very interesting. I'm wondering whether distance and "direction" are an issue here? That is: over large distances (how) would (light speed) latency translate into phase change if "downstream stabilization" suddenly becomes "upstream".
(Sorry for asking such a poorly stated question that I really haven't thought through — I know very little about electricity and you seem to understand quite a lot about this subject.)
Someone have a link to 101 power transmission? I find this fascinating.
Good instinct. There is a site that measures frequency in several places in Europe and shows the phase difference. [0]
The phase difference is not really about distance it's more about energy flows, where it's lagging there more power is used and where it is leading more power is generated. The flow will be from early phase to later.
So I imagine phase difference can be a serious issue, or at least something that needs to be mitigated and monitored continuously (evidently). I'm assuming a DC power network intrinsically solves this (in case of solar energy).
But how would current and voltage be stabilized in that case? Just huge capacitors? Chemical batteries?
Frequency and phase difference are indicators of grid balance.
Grid itself can't store energy, the generation and consumption needs to be in balance.
If transmission balance goes out of whack more electrons want to flow to specific places and will always try to take the path of least resistance.
Those paths (as in transmission lines) have their current capacity measured in Amps and when it gets too much their protective equipment in the for of active or passive circuit breakers will take them offline (trip) therefore moving the current down next best paths and further increasing the likelihood of trips.
Voltage is regulated by changing the windings of transformers in AC-AC systems or by transistors/thyristors in DC coupled networks.
Frequency has usually been regulated by spinning mass, a steam powered generator has a pretty large inertia and when it slows down there is a governor or other control mechanism to add energy to the generator via opening steam valves and maybe adding fuel. If speed goes too high it is also reduced.
For large load changes there are further compensatory mechanisms. Like heavy industrial plants measure grid frequency and when it falls below lets say 49.9Hz then they will immediately trip themselves offline and shed a huge amount of load from the grid. They get paid for this.
> Grid itself can't store energy, the generation and consumption needs to be in balance.
So while there may be huge variance in on both sides (a sunny day, a wind gust versus switching on the AC a train leaving the station) the only way to adjust is open a valve add steam, fuel? Will that scale to when, say, 80% of electricity sources are weather dependent? Or is that the pumped hydro / big batteries / future technology stuff?
Grids have many-many consumers and many generators. So switching on a single AC does not have a noticeable effect. There are however correlated events like the famous East Enders peak in the UK (daily TV show at the end of which a large number of britons go and make tea with their 2kW electric kettles).
But weather can span large areas and the solutions can be roughly categorized as:
- some form of energy storage: batteries, hydro (can be pumped), flywheels, etc
- dispatchable power - gas fired turbines, coal or wood fired thermal plants, nuclear, etc
- demand side response - time of use pricing (like nordpool spot market prices) or getting paid to switch off your AC during peak hours, etc.
Traditionally we have had a grid management mindset of "generation adapts to load", everyone uses as much and when they need and grid/generation adapts to it.
With only renewables the mental model of "load follows generation" could make sense, people (or rather peoples devices) get a signal when it is most beneficial to consume and when not to.
I think the reality will be some combination of all of the above. Mostly renewables but also diverse set of renewables that are somewhat anti-correlated, like wind+solar plus distributed. The shortfalls could be filled with natural gas fired power plants. Some nuclear when/if built/available combined with smart cars and devices. V2G will get there eventually as well and then the car battery will have much more energy available than a typical home uses in a day.
> There are however correlated events like the famous East Enders peak in the UK (daily TV show at the end of which a large number of britons go and make tea with their 2kW electric kettles
Within reason. If you lead or lag too much it will cause trouble (either for you or for other consumers and in a really bad case for the grid equipment itself).
That's why the grid will selectively island parts that are too far out of phase. Normally this should not happen though.
If we're going to use circuit terminology I think the physics of a flywheel are more like some kind of AC Inductor. DC Inductors resist changes in the flow of current, keeping current flowing even when circuit conditions change. It also helps that the parts of an inductor and flywheel that are in contact with the circuit/grid are coils of wire wrapped around an iron/magnetic core.
We are not talking about the energy balance, we are talking about grid strength/inertia also known as ancillary services. Two orthogonal concepts people tend to mix up.
The article mentions the critical parameters which historically have been sourced from big heavy generators like hydro, coal, nuclear or CCGT plants:
- Frequency regulation: When grid power crashes or surges, the device immediately releases or absorbs energy to minimize fluctuation in the AC frequency;
- Short circuit power: When the grid experiences a short circuit, the crashing voltage releases a tripling or more of current from rotating machines which signals breakers on the grid to activate and quickly isolate the fault;
- Voltage support: Producing current and voltage that are out of phase generates so-called reactive power that pushes the local grid’s voltage up or down to stabilize system voltage and/or increase the flow of real power.
> All nine of the Baltics’ synchronous condensers will have power-boosting flywheels, as she explains, equipping each installation with up to 2,200 megajoules of energy.
Though 97% of that energy isn’t available to the grid as the name synchronous condenser implies.
It's not that much energy anyway. 1kwh is about 3.6 megajoule. 2200 times 9 divided by 3.6 is about 5.5mwh. This is obviously not intended as a battery but more as a very low latency control mechanism to control frequencies and voltages. You'd only be able to use it for very short bursts of energy probably in the order of a few seconds or minutes.
You'd use something like this while bringing online alternative sources of energy, which takes time. Of course a grid battery probably wouldn't need this as it would be similarly quick to come online. Which raises the question why they are going for synchronous condensers instead of grid battery. One doesn't exclude the other of course.
I don't see how it implies that. In a DC power supply, for example, you can stick a regular capacitor (condenser) in parallel with the DC output and it will smooth out fluctuations in the voltage. The energy stored in that capacitor isn't available for you to use. You need the capacitor to stay charged so it can maintain the target voltage level. The only way to get a capacitor to be at a certain voltage is to charge it.
This is evidently something similar but for AC. It stabilizes the AC voltage / phase because its momentum pushes back against whatever tries to disturb it.
The flywheel is directly connected to the synchronous condenser's rotor, and that rotor is locked to the grid's frequency. The grid's frequency must be maintained within a very narrow range (for a variety of reasons), so the actual speed difference of the flywheel between "full" and "the grid is shutting down" is very small and so most of the energy cannot be put into the grid. This is why flywheel storage uses variable-frequency drive systems; to be able to pull energy out of the flywheel over the entire range of full-speed to ~standstill.
Oh, I see now. We've been talking past each other.
You mean, "Though 97% of that energy isn’t available to the grid COMMA as the name synchronous condenser implies."
You don't mean (as I read it before), "Though 97% of that energy isn’t available to the grid, and the name synchronous condenser implies the energy is available."
>The energy stored in that capacitor isn't available for you to use.
Well, it's only available to use when the power fails or something like that.
When you first power up, it requires a finite amount of time for the storage/filter capacitor(s) to charge up to their full design voltage before your circuit really works as intended.
Later when you disconnect incoming power, the stored energy from the capacitors does continue to supply DC power to your circuit for a finite amount of time afterward, at declining voltage as the capacitors are drained.
>This is evidently something similar but for AC. It stabilizes the AC voltage / phase because its momentum pushes back against whatever tries to disturb it.
Yes, I think this is it.
Seems to me these massive AC stabilizers would help maintain frequency and voltage during unavoidable events where the grid dropped below nominal, by more gracefully dropping when necessary as the grid sucks momentum from the stabilizer down to its own level at the time.
And if power completely failed it should end up in a more graceful "wind-down" as all momentum for all stabilizers require a finite amount of time to come to a complete halt, letting whatever limited amount of stored energy they contain be delivered to the grid until there is no more.
He is one of those Russian trolls who roams around HN telling that the slaves brought to the Americans should be thankful for the free trip they got. Except since they work on a different historic context, their vile nature gets lost on most readers.
Pre-WWII Estonia, Latvia and Lithuania were quite well developed small countries in Europe. Not on par with industrial powerhouses like the UK, but not the most undeveloped parts of Europe either. Estonia is a particularly notable example, since it shares lots of traits with Finland, comparing them is almost like a twins study. In 1938, Estonian and Finnish GDP per capita were very close, 3771 and 3589 dollars respectively.[1] Both were invaded by the USSR in 1939/40. Finland lost territory, but successfully fought Russians off and remained independent. Estonia was occupied by the USSR until 1991.
By 1995, the GDP per capita of Finland was 26 271 dollars, while Estonian GDP was 3134 dollars. In 2021, the Finnish GDP per capita was 53 489 dollars, while Estonian GDP had risen to 27 943 dollars.[2][3]
That's what 50 years of Russian rule does to a country - incredible economic stagnation, and then incredible rebound as soon as Russian tanks rolled out. In early 1990s, the average monthly wage in Estonia was 37 dollars. In 2023, it is 1800 dollars.
Russian trolls love to say how they "built the infrastructure", but they fail to mention that the natural pace of development would've been a much faster, like it is now.
And speaking of that "infrastructure", to a large degree it consisted of extremely polluting factories that produced uncompetitive garbage and went bankrupt as soon as free trade with rest of the world opened up. A great example of their "infrastructure" has been immortalized in Tarkovsky's sci-fi movie Stalker. The polluted wastelands with foaming rivers and white ebbs falling down like snow in summer weren't special effects. That was toxic waste from an upstream chemical plant that directed its waste unfiltered into a nearby river. Several crew members, including Tarkovsky himself, fell ill and died due to the poisioning received there.[4] Cleanup of such "infrastructure" continues to this day, 30 years later.
Beware of Greeks bearing gifts, and Russians building infrastructure.
Just writing in case some reader wonders why the downvotes.
Estonia was independent before the second world war and was doing very well. After the second world war until the nineties it was under Soviet occupation. During the occupation, there were mass deportations to Siberia, socialization of property, prevention of travel, prevention of free information and prevention of free enterprise and all those things. Until Estonia became independent again. The economic growth has been rapid since.
I'm lithuanian and this is false propaganda, Lithuania was independant before Rusian occupation back before the world wars and in between the World Wars, unless you consider Stalin and Hitler splitting lands as "purchasing".
The last couple of years I have been working hard at not directing my animosity towards the Russian state against Russian people. Post like yours makes that much harder. Almost no other people will glorify their past and current crimes like Russians do.
Nationalistic swipes are not welcome here, regardless of which nations you have a problem with. We ban accounts that post like this, so please don't do it again.
> USSR was an union of Republics, of which Russian SSR was just the one.
As the quote goes, "All animals are equal, but some animals are more equal than others." Pretending Russia didn't have a special status in the USSR doesn't win points in an argument, it just makes you look misinformed.
Whoa, you can't post slurs or attacks like this to HN, regardless of how wrong someone else is or you feel they are. We ban accounts that do this, so please don't do it again.
Nationalistic swipes are not welcome here, regardless of which nations you have a problem with. We ban accounts that post like this (and you have a long history of posting like this), so please stop.
As an aside, one of the most stunning proofs of how successful the European Union is happened with the grid. On 8 January 2021, the synchronous area of Continental Europe split into two, the system separation resulted in a deficit of power (approx. -6.3 GW) in the North-West Area and a surplus of power (approx. +6.3 GW) in the South-East Area,
The reaction speed was something to behold. The event happened at 14:05 CET, at 14:09 CET the Transmission System Operators (TSOs) were in teleconference but by then some 1.7GW capacity in France and Italy was dropped and 420 MW and 60 MW was activated in the Nordic and Great Britain. Customers barely felt it: only 70 MW in the North-West Area and 163 MW in the South-East Area were disconnected. By 15:08 the event concluded.
Yes, there was a mistake in the processes which led to the event in special circumstances but , I believe , the respected readers of HN know this all too well , the big question is what happens when an emergency hits. And those processes held up spectacularly.
> Europe’s grid, which is usually connected from Lisbon to Istanbul, split into two as the northwest and southeast regions struggled to keep the same frequency. The problem originated in Croatia and led to the equivalent of 200,000 households losing power across Europe. Supply to industrial sites was cut in France and Italy.
> Transmission grids need to stay at a frequency of 50 hertz to operate smoothly and any deviations can damage equipment that’s connected. Had the frequency swings not been reduced within minutes, it could have caused damage across the entire European high voltage network, potentially causing blackouts for millions.
> A fault at a substation that caused overloading on other parts of Croatia’s grid has been identified as the cause of the issue, network operators concluded Tuesday.
> “The problem isn’t posed by growing green electricity directly but by shrinking conventional capacity,” said Eglantine Kuenle, chief electricity systems modeler at the EWI Institute of Energy Economics at Cologne University. “The upshot is a gap in secure power generation and grid balancing that must be fixed.”
Personal thoughts. I knew we had an interconnected grid, but I had no idea it span from Portugal to Türkiye, nor that the rest of Scandinavia wasn't connected. For a system as critical, and as complex, it seems like a feat of engineering on all sides involved.
Fortunately they are not in charge of English. Not even the English government is. At most they are in charge of their respective versions and advocacy of it.
Alphabets and certainly diacritics are used differently in different languages, so insisting on a certain way of writing can only lead to inconsistent pronunciation.
I just hope they don't go back to Arabic alphabet, it would be a pain to write. Btw when will China start demanding we refer to it as Zhōngguó, or better yet 中國 /s
I think this illustrates the point well: if they were to write it in another script completely, English would adopt some transliteration of the name, i.e. an exonym.
Official reports can be self-serving, both intentionally and unintentionally (it represents only one perspective). Journalists talk to many sources with many perspectives.
Journalists might but the publication which did the supermicro spy chip story without retracting it does not deserve that moniker. (Small footnote: I was a columnist, later editor, even later part of the editorial board of the largest computer monthly in Hungary in what now feels like a different life a quarter century ago.)
At the time, it was said this plan was the immediate reason for the invasion: letting the sync finish would have crossed some measure of western integration for the Kremlins tastes.
To be a little nit-picky the grid includes Scandinavia through HVDC connections with the rest of Europe, see [1] for the entire ENTSO-E grid. If you mean the synchronous grid, Denmark is part of Scandinavia and its continental part is synchronised with the rest of Europe.
>As an aside, one of the most stunning proofs of how successful the European Union is happened with the grid. On 8 January 2021, the synchronous area of Continental Europe split into two
The European grid has nothing to do with the EU. The grid includes non-EU countries like Switzerland and Norway. The UK did not leave the grid after Brexit; its interconnections with Ireland and the continent still exist.
The US and Canada's grids are interconnected without the two nations being integrated as closely as the EU member states are.
ENTSOE-E exists because of the 2009/72/EC directive. It's an EU entity. As with many such, they also allow / work with entities outside of the EU but that doesn't change the fact this is an association existing under and because of the EU legal framework.
Texas is connected to Mexico and some other exceptions. The fed though would rather frozen dead Texans than deregulate and allow ERCOT to connect as they do to Mexico. Fed basically holding some of the poorer rural Texans hostage to influence some rich ERCOT bureaucrats to change their regulations -- pretty fucked up IMO.
Texas has made a conscious decision since 1935 when FDR signed the Federal Power Act to stay away because they didn't want the feds to mess with their grid. The feds have no power here because the Texas grid does not cross state lines. When West Texas Utilities did connect through state lines in 1976 (called the Midnight Connection) both HL&P and Texas Electric Service Company immediately disconnected from them to avoid falling under federal regulation. It was not the feds. https://www.bakerinstitute.org/research/connecting-past-and-...
Yes the federal regulations make demands in order to connect. The feds can release their hostages and drop the federal regulation demands and deregulate and Texas would surely connect to these interstate grids as they did to Mexico.
Indeed a sync'd grid is what is typically being called a single grid. HVDC only got the required fast breaker a decade ago so it is nowhere near as widely deployed as the AC system (it's hard to make a HVDC breaker because even if an AC breaker arcs it'll self extinguish in an extremely short period of time as the voltage crosses zero, HVDC never does this so you need something to force the current to zero). Maybe the definition will change over time, it is, after all, completely arbitrary.
And sure, other countries can integrate too, and in fact do. Nobody said only EU members are allowed to do it. It is however the largest grid on earth, and therefore a technical and political feat.
The EU itself is a thing to behold. Just managing to prevent wars between their members for so many decades is a remarkable accomplishment, unheard of in the continent's troubled history.
Not perfect, and certainly not invulnerable to bad actors, but still a beautiful accomplishment of will and politics.
Almost all of us in Europe have never known anything but this peace so it almost feels a given. (I doubt a lot of readers are above eighty years old.) Yet a lot of kvetching about regulations happen and so it's good to remind people they have their own use.
I've come to think that the so-called "most peaceful era in human history" as the post-Cold War era has been often called is more aptly "most peaceful era in western history".
Plenty of strife and conflict can be and are found where most western eyes generally don't look.
By that measure, you'd consider the peace ended in 1956 when Russia -- then called the Soviet Union -- re-invaded Hungary after very briefly withdrawing. (As an aside, when the National Bank of Ukraine last year opened two donation accounts, I sent 1956 EUR to both. I am not subtle with my messaging.)
I don't know what 1956 felt like in western Europe but the current situation definitely doesn't feel like peace even though the war is not fought in western Europe. The war is at the EU border with stray missiles and overreaching Russian attacks already having hit EU territory.
> Russian attacks already having hit EU territory.
On 15 November 2022, a missile struck the territory of Poland at the village of Przewodów near the border with Ukraine, killing two people.[1][2][3] ... It was the first incident of a missile (vis-a-vis prior UAV incursions) fired from Ukrainian army[6] landing and exploding within NATO territory ... Initially Ukraine accused Russia of striking Poland,[9] while United States claimed that the missile was likely to have been an air defence missile fired by Ukrainian forces at an incoming Russian missile.[10][11][12] This was later confirmed in September 2023 by the Polish Prosecutor's Office, which stated that the explosion was caused by an out of control air-defence missile S-300.[6][13]
Seems like the trick really is to deeply intertwine economies.
It kind of feels similar to how monarchs tried to form lasting peace further back: inter-marry so that everyone is someone’s cousin they grew up with. Of course that didn’t exactly work perfectly.
Yeah my thoughts too. My feeling is that there won’t be some perfect solution that stops all wars. But that it was a very rational idea that may have stopped some.
Indeed it would be interesting to see experts attempt to enumerate situations that were avoided through this approach. Though I’m not sure if that’s even possible given it requires a form of alternate reality synthesis which is all but pure bias.
A statistical approach may find there’s still too little data?
But the economies were not so intertwined. The British, French, etc. were massively profiting from exploiting their colonial holdings while the Germans and Austro-Hungarians were being left in the dust, slave labour abolished some decades or centuries ago.
That was the thesis of "The Great Illusion", published in 1911. Basically, nation states would rationally avoid war, as it is pure downside, economically. Obviously it's at least insufficient.
I think it's a totally naive view. Even if we limit ourselves to only thinking about rational actors, we must always ask about economic costs for whom. Nation states do not operate as a unit as a rational economic actor -- we must look at the competing actors within. One group could somewhat win, and another substantially lose, and that may net out to a negative -- it happens regularly. Many are clamoring for it right now -- a new Cold War against China.
Intertwined economies are part of it but I think people underestimate the importance of norms. EU leaders and ministers are regularly in meetings together. When there is a crisis now the reaction of all EU leaders is to hold a conference for them to hash out how to deal with the situation. This establishment of the norm of talking whenever there's an issue is very powerful.
Flywheels are underrated tech for both stability and decentralized energy storage. They should receive environmental funding just like solar and wind do.
Can you point to resources explaining why they're a good choice?
Because the general consensus seems to be that large things like pumped hydro are good for centralized energy storage, while batteries are the choice for decentralized energy storage -- whether in your utility closet or in your EV.
Why should anyone choose a flywheel over a battery?
What I've seen is they require fancy materials (carbon fiber, etc) due to the extremely high rotation rates (>100k rpm). For maximum efficiency, the flywheel needs to be in a vacuum to eliminate frictional air resistance losses. They also need magnetic bearings.
None of these are exactly a problem, they just cost money to implement properly.
I would say this copy + pasted list is not great.
No HVAC required - ok but you do need to suck down a huge vacuum, which is a lot more difficult than traditional HVAC
Hot and cold - see above point
All steel - not sure about that, maybe for lower speed applications, which reduces the amount of energy stored
Safe & reliable - hard to say that a huge mass spinning >100k rpm is "safe". By itself there is no fire hazard sure. but what if your magnetic bearings fail and it hops off and starts trying to escape it's (vacuum) enclosure. Then you have tons of sparks and pressure differences and other non-fun things.
O&M - [citation required]
30 year life - surely with all the plusses listed, it should be longer than 30 year life?
I think rather than think about it as "pros and cons", a better approach is to think about where these various types of storage are used. I think the analogy of hard disk drive -> RAM -> on-chip cache for memory storage (that is cheapest/longest lived/slowest to most expensive/short term/fastest) also works well for energy storage:
1. Pumped hydro is currently best for long term-storage. The lack of other cost-competitive long-term storage options is currently one of the biggest issues with renewables and an active area of investigation.
2. Batteries are good for daily smoothing (i.e. when the sun goes down), but they have limited charge/discharge cycles, they lose charge over time, and they don't, as of yet, have storage capacities needed for long term storage.
3. As the article points out, flywheels are good at instantly changing output based on changes in the grid, so they're good for frequency regulation and onboarding/offboarding new energy sources. Their biggest downside is their limited capacity compared to other tech.
At least two of these (85% efficiency and fast response time < 1 sec) are factually incorrect if presented as an advantage of flywheels over batteries, which do better on those metrics.
flywheels can go through charge and discharge cycles pretty much infinitely at least compared to batteries. Somebody posted a chart a chart on reddit recently comparing energy storage technologies based on how long they need to discharge for and how frequently https://www.reddit.com/r/dataisbeautiful/comments/17r9q6s/oc...
When you have multiple cycles per day, the higher price of flywheels trumps over the limited but cheaper battery lifespan. Batteries degrade with charge cycles.
Are they safe and simple enough to operate at the neighborhood or even household level as a backup energy storage, where the grid is faulty? For example, in some region of Africa?
People explored them in the 2008-ish climate boomlet and it was hard to make the physics/costs work. If something has changed since then it might be worth looking at again, else that's probably why nobody is pursuing them today.
Physics work, but cost has historically been the issue. My current project involves driving down the cost to make extremely affordable 50 kWh flywheel modules.
The headline implies the Baltic states will have an independent electricity grid, but it's just switching dependence from Russia to the EU (for electricity) and the USA (for liquified natural gas imports).
Lithuania, Estonia and Latvia would be better off eliminating those dependencies entirely by focusing on expanding their domestic renewable energy production infrastructure.
> Lithuania, Estonia and Latvia would be better off eliminating those dependencies entirely by focusing on expanding their domestic renewable energy production infrastructure.
Perhaps, but the time scale for that is much longer than this, and they're very eager to switch ASAP.
Estonia doesn't really import any electricity from Russia, it's primarily export. Also these connections in general are for cost and fault tolerance. Estonia has enough domestic power plant capacity (including domestic shale oil mining to fuel it) to cover even peak usage. It's just often cheaper to import from Finland.
There are also a lot of renewable energy projects in progress to replace the shale oil systems, but again - capacity isn't the issue.
Indeed, they do. The Wikipedia page photos are some of my favorite photos of power tech.
Another thing that made a really strong impression was visiting a power dam and realizing that it was almost dead quiet while an enormous amount of power was being generated. Just a slight hum and a vibration in the floor, that was all.
But if those rotors were even a few grams out of balance, you'd feel it. Also, if something went wrong with the valves, you'd also hear it. Right before you drowned and/or were killed by flying concrete. Moving water does NOT like to stop.
I've seen some videos which show, if I understood the description correctly, chambers which contain the overpressure from these water hammer events. For instance: https://www.youtube.com/watch?v=fJVBlhgt9j8
That's impressive. I've seen a 2" butterfly valve attached to a stepper motor blown clear off the tube it was on because it closed too quickly. Oops... expensive lesson.
Oh, that's ugly. Not to be callous: but it could have been much worse still, in spite of all of the failing safety systems. The dam itself could have failed and the downstream effects would have been on a completely different level.
... meanwhile, it's hard to believe that Japan still runs two separate grids at two separate frequencies. Seems like it'd be worth sorting out a transition plan instead of building that sort of facility, and (presumably) a bunch of others just like it.
It’s not worth the eye watering amount of money it would cost to change.
It took nearly seventy years to transition users off the much smaller NYC DC grid, which was obsolete in the 1920s!
On the contrary, as inverters and HVDC get cheaper, large synchronous grids are less worthwhile. Smaller grids are more resilient and easier to recover; that's the direction we're headed in, with plans to decouple some of these continental grids.
Since the article mentions the Kaliningrad exclave: what will actually happen with it once the Baltic states shut down the power lines to Russia? Then there will also be no way to transfer power from Russia to Kaliningrad - will they be forced to only rely on those power plants the article mentions?
The article explains this. Russia built 4 new gas fired power plants and an LNG import station at a port in Kaliningrad. The enclave is self sufficient now.
Couldn't the Baltic states switch synchronous zones by disconnecting from the Russian grid, blacking out and then bootstrapping using the European grid? That would break continuity of service and require a black start (far from ideal), but that's a contingency they must've thought of in case they suddenly got cut off from Russia and Belarus for some reason.
As I understood from the discussions last winter here in Austria, a black start is not a single switch, you need to start on one side of a country (where you have power or blackstart-capable plants) and then work your way through the grid. That takes a while and you don't want citizens without power even for a few hours if you can help it.
That LitPot Link [1] to Poland looks really vulnerable if Russia / Belarus decide the Baltics need to rejoin. There's three others (Harmony Link won't be completed to 2028), yet that looks like a quick half-day to sever. Only 40km to the corner of Belarus, most artillery listed here can hit 40km+ {2] Get something like this if it goes total war. [3]
Nearly all of the purposes for these flywheels could equally be met with existing infrastructure with software only changes.
Solar inverters can produce/absorb reactive power easily - but while that can frequently be configured from the control panel of individual units, rarely is that ability exposed to grid operators.
Inverters at DC undersea links can do the same. As can some kinds of wind turbine.
All three can also absorb harmonic power and emit it as fundamental frequency power.
Battery energy storage systems can also do all of that, plus also provide 'simulated spinning reserve', and also provide brief huge increases in energy output to deal with various collapse conditions.
Wind can also do this (with caveats).
However, despite lots of 'green' energy sources having the necessary abilities, it frequently is lacking software support, particularly in the 'control plane'. Part of that is because there is no legal mandate to have these abilities, and there is (in most markets) no payment for providing this service. Therefore operators don't bother to enable these features.
In the case where a system splits and one area is 6.3 GW in deficit how is an inverter going to conjure up that power?
The only thing that can help in that case is batteries.
98% of the power plants I’ve been to run the voltage regulator in voltage control mode with 5% droop. Solar and wind farms can do that too, and I am sure it is required by the system operators to allow them to connect.
If grid operators want more or less reactive power they call us and tell us to change our voltage setpoint on our plants. Can’t they do the same with solar and wind? The grid operator does not need real time control of the setpoint since the control loop responds in real time.
This isn't to deal with multi-minute power deficits in split grids. That is dealt with with fast acting generation or load shedding.
Solar and wind systems today typically do not have a voltage setpoint or control loop. That's because there is no big gas/steam valve to adjust the amount of power generated. The operator wants to inject all the power from the sun/wind into the grid, whatever the voltage.
An X% droop would be X% of the total generated energy wasted in the name of stability. Thats a lot of money, and they won't waste it unless required to.
Instead, power deficits in the 10's of millisecond range can be dealt with by inverters (which typically have storage capacitors for ~20ms worth of output). This covers large fault currents, and sudden inflows as bits of grid are reconnected.
Unfortunately, most of today's inverters, which have the capability to do that, will not, due to having code which will only operate the 'happy case'.
> Solar inverters can produce/absorb reactive power easily
> Solar and wind systems today typically do not have a voltage setpoint or control loop. That's because there is no big gas/steam valve to adjust the amount of power generated. The operator wants to inject all the power from the sun/wind into the grid, whatever the voltage.
reactive power being easily controlled is the same as a voltage control loop with droop when connected to a larger system.
Control of the traditional prime mover by way of devices like steam throttle valve controls real power (MW) and not voltage or reactive power (MVAR).
I am curious how an inverter operating away from unity power factor fails to deliver roughly the identical amount of energy as at unity. Can you provide a link that explains it? Traditional generators pump out the same MW barring losses due to increased current no matter the power factor. MW in mechanical * efficiency = MW out electrical. And of course there is a limit to how out of phase the voltage and current waveforms can be, usually +/- 0.9 pf.
A 60Hz cycle is 16.7 ms, A 13 kV breaker takes 80ms to open, to detect a fault (except for differential element) let alone clear it takes a lot longer than 20ms.
> Nearly all of the purposes for these flywheels could equally be met with existing infrastructure with software only changes.
While that's true, sometimes it's easier to have a single-purpose infrastructure, so that you don't have conflicting requirements.
For example, if a wind farm needs to feather its turbines due to excessive wind (which could damage the turbines), that could conflict with a simultaneous objective for frequency regulation.
168 comments
[ 4.3 ms ] story [ 200 ms ] threadToday the research focuses on "Grid forming inverters". Taking the same principle as powering a home in island mode and stretching it to the entire grid allowing non-synchronous generators to provide the system strength.
Over time they are a net power drain for the grid, but as parent says offer synthetic grid stability independent of power sources.
(Sorry for asking such a poorly stated question that I really haven't thought through — I know very little about electricity and you seem to understand quite a lot about this subject.)
Someone have a link to 101 power transmission? I find this fascinating.
The phase difference is not really about distance it's more about energy flows, where it's lagging there more power is used and where it is leading more power is generated. The flow will be from early phase to later.
[0] https://gridradar.net/charts/map/map.html
But how would current and voltage be stabilized in that case? Just huge capacitors? Chemical batteries?
Grid itself can't store energy, the generation and consumption needs to be in balance.
If transmission balance goes out of whack more electrons want to flow to specific places and will always try to take the path of least resistance.
Those paths (as in transmission lines) have their current capacity measured in Amps and when it gets too much their protective equipment in the for of active or passive circuit breakers will take them offline (trip) therefore moving the current down next best paths and further increasing the likelihood of trips.
Voltage is regulated by changing the windings of transformers in AC-AC systems or by transistors/thyristors in DC coupled networks.
Frequency has usually been regulated by spinning mass, a steam powered generator has a pretty large inertia and when it slows down there is a governor or other control mechanism to add energy to the generator via opening steam valves and maybe adding fuel. If speed goes too high it is also reduced.
For large load changes there are further compensatory mechanisms. Like heavy industrial plants measure grid frequency and when it falls below lets say 49.9Hz then they will immediately trip themselves offline and shed a huge amount of load from the grid. They get paid for this.
So while there may be huge variance in on both sides (a sunny day, a wind gust versus switching on the AC a train leaving the station) the only way to adjust is open a valve add steam, fuel? Will that scale to when, say, 80% of electricity sources are weather dependent? Or is that the pumped hydro / big batteries / future technology stuff?
[Sorry for going off topic, here]
But weather can span large areas and the solutions can be roughly categorized as:
- some form of energy storage: batteries, hydro (can be pumped), flywheels, etc
- dispatchable power - gas fired turbines, coal or wood fired thermal plants, nuclear, etc
- demand side response - time of use pricing (like nordpool spot market prices) or getting paid to switch off your AC during peak hours, etc.
Traditionally we have had a grid management mindset of "generation adapts to load", everyone uses as much and when they need and grid/generation adapts to it.
With only renewables the mental model of "load follows generation" could make sense, people (or rather peoples devices) get a signal when it is most beneficial to consume and when not to.
I think the reality will be some combination of all of the above. Mostly renewables but also diverse set of renewables that are somewhat anti-correlated, like wind+solar plus distributed. The shortfalls could be filled with natural gas fired power plants. Some nuclear when/if built/available combined with smart cars and devices. V2G will get there eventually as well and then the car battery will have much more energy available than a typical home uses in a day.
Cruachan to the rescue.
https://en.wikipedia.org/wiki/Cruachan_Power_Station
Zero to full production in two minutes, 30 seconds in an extreme case if required. It's the Power Infrastructure equivalent of a supercar.
That's why the grid will selectively island parts that are too far out of phase. Normally this should not happen though.
https://en.wikipedia.org/wiki/Variable_shunt_reactor
Sigh…
The article mentions the critical parameters which historically have been sourced from big heavy generators like hydro, coal, nuclear or CCGT plants:
- Frequency regulation: When grid power crashes or surges, the device immediately releases or absorbs energy to minimize fluctuation in the AC frequency;
- Short circuit power: When the grid experiences a short circuit, the crashing voltage releases a tripling or more of current from rotating machines which signals breakers on the grid to activate and quickly isolate the fault;
- Voltage support: Producing current and voltage that are out of phase generates so-called reactive power that pushes the local grid’s voltage up or down to stabilize system voltage and/or increase the flow of real power.
This is about Inertia and frequency control. Not about bulk energy storage.
Though 97% of that energy isn’t available to the grid as the name synchronous condenser implies.
You'd use something like this while bringing online alternative sources of energy, which takes time. Of course a grid battery probably wouldn't need this as it would be similarly quick to come online. Which raises the question why they are going for synchronous condensers instead of grid battery. One doesn't exclude the other of course.
This is evidently something similar but for AC. It stabilizes the AC voltage / phase because its momentum pushes back against whatever tries to disturb it.
You mean, "Though 97% of that energy isn’t available to the grid COMMA as the name synchronous condenser implies."
You don't mean (as I read it before), "Though 97% of that energy isn’t available to the grid, and the name synchronous condenser implies the energy is available."
Well, it's only available to use when the power fails or something like that.
When you first power up, it requires a finite amount of time for the storage/filter capacitor(s) to charge up to their full design voltage before your circuit really works as intended.
Later when you disconnect incoming power, the stored energy from the capacitors does continue to supply DC power to your circuit for a finite amount of time afterward, at declining voltage as the capacitors are drained.
>This is evidently something similar but for AC. It stabilizes the AC voltage / phase because its momentum pushes back against whatever tries to disturb it.
Yes, I think this is it.
Seems to me these massive AC stabilizers would help maintain frequency and voltage during unavoidable events where the grid dropped below nominal, by more gracefully dropping when necessary as the grid sucks momentum from the stabilizer down to its own level at the time.
And if power completely failed it should end up in a more graceful "wind-down" as all momentum for all stabilizers require a finite amount of time to come to a complete halt, letting whatever limited amount of stored energy they contain be delivered to the grid until there is no more.
[citation needed]
Pre-WWII Estonia, Latvia and Lithuania were quite well developed small countries in Europe. Not on par with industrial powerhouses like the UK, but not the most undeveloped parts of Europe either. Estonia is a particularly notable example, since it shares lots of traits with Finland, comparing them is almost like a twins study. In 1938, Estonian and Finnish GDP per capita were very close, 3771 and 3589 dollars respectively.[1] Both were invaded by the USSR in 1939/40. Finland lost territory, but successfully fought Russians off and remained independent. Estonia was occupied by the USSR until 1991.
By 1995, the GDP per capita of Finland was 26 271 dollars, while Estonian GDP was 3134 dollars. In 2021, the Finnish GDP per capita was 53 489 dollars, while Estonian GDP had risen to 27 943 dollars.[2][3]
That's what 50 years of Russian rule does to a country - incredible economic stagnation, and then incredible rebound as soon as Russian tanks rolled out. In early 1990s, the average monthly wage in Estonia was 37 dollars. In 2023, it is 1800 dollars.
Russian trolls love to say how they "built the infrastructure", but they fail to mention that the natural pace of development would've been a much faster, like it is now.
And speaking of that "infrastructure", to a large degree it consisted of extremely polluting factories that produced uncompetitive garbage and went bankrupt as soon as free trade with rest of the world opened up. A great example of their "infrastructure" has been immortalized in Tarkovsky's sci-fi movie Stalker. The polluted wastelands with foaming rivers and white ebbs falling down like snow in summer weren't special effects. That was toxic waste from an upstream chemical plant that directed its waste unfiltered into a nearby river. Several crew members, including Tarkovsky himself, fell ill and died due to the poisioning received there.[4] Cleanup of such "infrastructure" continues to this day, 30 years later.
Beware of Greeks bearing gifts, and Russians building infrastructure.
[1] https://i.imgur.com/PolvBbR.jpg
[2] https://wits.worldbank.org/CountryProfile/en/Country/FIN/Sta...
[3] https://wits.worldbank.org/CountryProfile/en/Country/EST/Sta...
[4] https://faroutmagazine.co.uk/stalker-killed-andrei-tarkovsky...
When the Russian Empire took the Balic states the restored and increased Serfdom to the strongest it has ever been.
Russian Empire and the Soviet Union have been horrible for the Baltics literally for 100s of years.
Nationalistic swipes are not welcome here, regardless of which nations you have a problem with. We ban accounts that post like this, so please don't do it again.
https://news.ycombinator.com/newsguidelines.html
As the quote goes, "All animals are equal, but some animals are more equal than others." Pretending Russia didn't have a special status in the USSR doesn't win points in an argument, it just makes you look misinformed.
If you wouldn't mind reviewing https://news.ycombinator.com/newsguidelines.html and taking the intended spirit of the site more to heart, we'd be grateful.
Nationalistic swipes are not welcome here, regardless of which nations you have a problem with. We ban accounts that post like this (and you have a long history of posting like this), so please stop.
https://news.ycombinator.com/newsguidelines.html
The reaction speed was something to behold. The event happened at 14:05 CET, at 14:09 CET the Transmission System Operators (TSOs) were in teleconference but by then some 1.7GW capacity in France and Italy was dropped and 420 MW and 60 MW was activated in the Nordic and Great Britain. Customers barely felt it: only 70 MW in the North-West Area and 163 MW in the South-East Area were disconnected. By 15:08 the event concluded.
Yes, there was a mistake in the processes which led to the event in special circumstances but , I believe , the respected readers of HN know this all too well , the big question is what happens when an emergency hits. And those processes held up spectacularly.
> Europe’s grid, which is usually connected from Lisbon to Istanbul, split into two as the northwest and southeast regions struggled to keep the same frequency. The problem originated in Croatia and led to the equivalent of 200,000 households losing power across Europe. Supply to industrial sites was cut in France and Italy.
> Transmission grids need to stay at a frequency of 50 hertz to operate smoothly and any deviations can damage equipment that’s connected. Had the frequency swings not been reduced within minutes, it could have caused damage across the entire European high voltage network, potentially causing blackouts for millions.
> A fault at a substation that caused overloading on other parts of Croatia’s grid has been identified as the cause of the issue, network operators concluded Tuesday.
> “The problem isn’t posed by growing green electricity directly but by shrinking conventional capacity,” said Eglantine Kuenle, chief electricity systems modeler at the EWI Institute of Energy Economics at Cologne University. “The upshot is a gap in secure power generation and grid balancing that must be fixed.”
https://web.archive.org/web/20230621192146/https://www.bloom...
----
Personal thoughts. I knew we had an interconnected grid, but I had no idea it span from Portugal to Türkiye, nor that the rest of Scandinavia wasn't connected. For a system as critical, and as complex, it seems like a feat of engineering on all sides involved.
Not according to the Turkish government.
https://www.theguardian.com/world/2022/jun/03/turkey-changes...
Alphabets and certainly diacritics are used differently in different languages, so insisting on a certain way of writing can only lead to inconsistent pronunciation.
How is that related to what we're talking about?
> does not deserve that moniker
That's pretty extreme. One story you didn't like, and that's it? I don't think anything, certainly not press releases, will meet your standard.
[1] https://www.scientificamerican.com/article/how-ukraine-unplu...
[1]: https://www.entsoe.eu/data/map/downloads
WP articles about this: https://en.wikipedia.org/wiki/Synchronous_grid_of_Continenta... https://en.wikipedia.org/wiki/European_super_grid
The European grid has nothing to do with the EU. The grid includes non-EU countries like Switzerland and Norway. The UK did not leave the grid after Brexit; its interconnections with Ireland and the continent still exist.
The US and Canada's grids are interconnected without the two nations being integrated as closely as the EU member states are.
Texas has made a conscious decision since 1935 when FDR signed the Federal Power Act to stay away because they didn't want the feds to mess with their grid. The feds have no power here because the Texas grid does not cross state lines. When West Texas Utilities did connect through state lines in 1976 (called the Midnight Connection) both HL&P and Texas Electric Service Company immediately disconnected from them to avoid falling under federal regulation. It was not the feds. https://www.bakerinstitute.org/research/connecting-past-and-...
And sure, other countries can integrate too, and in fact do. Nobody said only EU members are allowed to do it. It is however the largest grid on earth, and therefore a technical and political feat.
Not perfect, and certainly not invulnerable to bad actors, but still a beautiful accomplishment of will and politics.
Plenty of strife and conflict can be and are found where most western eyes generally don't look.
By that measure, you'd consider the peace ended in 1956 when Russia -- then called the Soviet Union -- re-invaded Hungary after very briefly withdrawing. (As an aside, when the National Bank of Ukraine last year opened two donation accounts, I sent 1956 EUR to both. I am not subtle with my messaging.)
On 15 November 2022, a missile struck the territory of Poland at the village of Przewodów near the border with Ukraine, killing two people.[1][2][3] ... It was the first incident of a missile (vis-a-vis prior UAV incursions) fired from Ukrainian army[6] landing and exploding within NATO territory ... Initially Ukraine accused Russia of striking Poland,[9] while United States claimed that the missile was likely to have been an air defence missile fired by Ukrainian forces at an incoming Russian missile.[10][11][12] This was later confirmed in September 2023 by the Polish Prosecutor's Office, which stated that the explosion was caused by an out of control air-defence missile S-300.[6][13]
> Neither Russia nor Ukraine are members of the EU.
Europe != EU
Also, explosives from the Russian invasion in Ukraine have hit the territories of two EU countries: Poland and Romania.
It kind of feels similar to how monarchs tried to form lasting peace further back: inter-marry so that everyone is someone’s cousin they grew up with. Of course that didn’t exactly work perfectly.
Did not work terribly well for the former Soviet republics :(
On one hand, I read experts say that. On the other, I read experts point out that it failed to prevent WWI.
I wonder what the consensus is, if there is one, and what the evidence is.
Indeed it would be interesting to see experts attempt to enumerate situations that were avoided through this approach. Though I’m not sure if that’s even possible given it requires a form of alternate reality synthesis which is all but pure bias.
A statistical approach may find there’s still too little data?
Yes, absolutely. Also, it generally makes us wealthier.
I think it's a totally naive view. Even if we limit ourselves to only thinking about rational actors, we must always ask about economic costs for whom. Nation states do not operate as a unit as a rational economic actor -- we must look at the competing actors within. One group could somewhat win, and another substantially lose, and that may net out to a negative -- it happens regularly. Many are clamoring for it right now -- a new Cold War against China.
The principle that member nations have alignment and act (mostly) in unison.
Because the general consensus seems to be that large things like pumped hydro are good for centralized energy storage, while batteries are the choice for decentralized energy storage -- whether in your utility closet or in your EV.
Why should anyone choose a flywheel over a battery?
Advantages over chemical batteries:
>85% round trip efficiency (DC)
>No daily cycling limitations
>No degradation over time
>Full power over full State-of-Charge range
>No HVAC required
>Operates in hot and cold environments (-20C to 50C)
>Fast response time (<1 second)
>Sustainable and recyclable all-steel design
>Safe & reliable–no fire hazard
>Lower O&M cost
>30-year design life
None of these are exactly a problem, they just cost money to implement properly.
I would say this copy + pasted list is not great.
No HVAC required - ok but you do need to suck down a huge vacuum, which is a lot more difficult than traditional HVAC
Hot and cold - see above point
All steel - not sure about that, maybe for lower speed applications, which reduces the amount of energy stored
Safe & reliable - hard to say that a huge mass spinning >100k rpm is "safe". By itself there is no fire hazard sure. but what if your magnetic bearings fail and it hops off and starts trying to escape it's (vacuum) enclosure. Then you have tons of sparks and pressure differences and other non-fun things.
O&M - [citation required]
30 year life - surely with all the plusses listed, it should be longer than 30 year life?
1. Pumped hydro is currently best for long term-storage. The lack of other cost-competitive long-term storage options is currently one of the biggest issues with renewables and an active area of investigation.
2. Batteries are good for daily smoothing (i.e. when the sun goes down), but they have limited charge/discharge cycles, they lose charge over time, and they don't, as of yet, have storage capacities needed for long term storage.
3. As the article points out, flywheels are good at instantly changing output based on changes in the grid, so they're good for frequency regulation and onboarding/offboarding new energy sources. Their biggest downside is their limited capacity compared to other tech.
https://amberkinetics.com/installation/the-reliable-energy-s...
https://amberkinetics.com/installations/
Placeholder site: vortical.io
Lithuania, Estonia and Latvia would be better off eliminating those dependencies entirely by focusing on expanding their domestic renewable energy production infrastructure.
Perhaps, but the time scale for that is much longer than this, and they're very eager to switch ASAP.
There are also a lot of renewable energy projects in progress to replace the shale oil systems, but again - capacity isn't the issue.
* https://new.abb.com/news/detail/19701/abb-wins-600-mw-hvdc-o...
Another thing that made a really strong impression was visiting a power dam and realizing that it was almost dead quiet while an enormous amount of power was being generated. Just a slight hum and a vibration in the floor, that was all.
75 deaths. RIP.
Clicking the prominent "refuse all" button works
It does seem a little weird though.
[1] https://spectrum.ieee.org/media-library/a-map-of-the-baltic-...
[2] https://www.army-technology.com/features/featurethe-10-most-...
[3] https://en.wikipedia.org/wiki/Upshot-Knothole_Grable#/media/...
Solar inverters can produce/absorb reactive power easily - but while that can frequently be configured from the control panel of individual units, rarely is that ability exposed to grid operators.
Inverters at DC undersea links can do the same. As can some kinds of wind turbine.
All three can also absorb harmonic power and emit it as fundamental frequency power.
Battery energy storage systems can also do all of that, plus also provide 'simulated spinning reserve', and also provide brief huge increases in energy output to deal with various collapse conditions.
Wind can also do this (with caveats).
However, despite lots of 'green' energy sources having the necessary abilities, it frequently is lacking software support, particularly in the 'control plane'. Part of that is because there is no legal mandate to have these abilities, and there is (in most markets) no payment for providing this service. Therefore operators don't bother to enable these features.
The only thing that can help in that case is batteries.
98% of the power plants I’ve been to run the voltage regulator in voltage control mode with 5% droop. Solar and wind farms can do that too, and I am sure it is required by the system operators to allow them to connect.
If grid operators want more or less reactive power they call us and tell us to change our voltage setpoint on our plants. Can’t they do the same with solar and wind? The grid operator does not need real time control of the setpoint since the control loop responds in real time.
Solar and wind systems today typically do not have a voltage setpoint or control loop. That's because there is no big gas/steam valve to adjust the amount of power generated. The operator wants to inject all the power from the sun/wind into the grid, whatever the voltage.
An X% droop would be X% of the total generated energy wasted in the name of stability. Thats a lot of money, and they won't waste it unless required to.
Instead, power deficits in the 10's of millisecond range can be dealt with by inverters (which typically have storage capacitors for ~20ms worth of output). This covers large fault currents, and sudden inflows as bits of grid are reconnected.
Unfortunately, most of today's inverters, which have the capability to do that, will not, due to having code which will only operate the 'happy case'.
> Solar and wind systems today typically do not have a voltage setpoint or control loop. That's because there is no big gas/steam valve to adjust the amount of power generated. The operator wants to inject all the power from the sun/wind into the grid, whatever the voltage.
reactive power being easily controlled is the same as a voltage control loop with droop when connected to a larger system.
Control of the traditional prime mover by way of devices like steam throttle valve controls real power (MW) and not voltage or reactive power (MVAR).
I am curious how an inverter operating away from unity power factor fails to deliver roughly the identical amount of energy as at unity. Can you provide a link that explains it? Traditional generators pump out the same MW barring losses due to increased current no matter the power factor. MW in mechanical * efficiency = MW out electrical. And of course there is a limit to how out of phase the voltage and current waveforms can be, usually +/- 0.9 pf.
A 60Hz cycle is 16.7 ms, A 13 kV breaker takes 80ms to open, to detect a fault (except for differential element) let alone clear it takes a lot longer than 20ms.
While that's true, sometimes it's easier to have a single-purpose infrastructure, so that you don't have conflicting requirements.
For example, if a wind farm needs to feather its turbines due to excessive wind (which could damage the turbines), that could conflict with a simultaneous objective for frequency regulation.