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To free the Baltic grid, old technology is new again

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Re: To free the Baltic grid, old technology is new again

#101

Post by janosdebugs »

boricj wrote: post #71

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.

Re: To free the Baltic grid, old technology is new again

#102

Post by b3orn »

PartiallyTyped wrote: post #58
chx wrote: post #31

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 CE…

I found this article from bloomberg on the event! > 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 freq…

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.

[1]: https://www.entsoe.eu/data/map/downloads

Re: To free the Baltic grid, old technology is new again

#103

Post by cesarb »

jacquesm wrote: post #93
jeffrallen wrote: post #87

Earlier quoted context omitted.

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.

Yes, the water hammer from a major dam must be quite impressive if you try to contain it by main force rather than to reduce the flow gradually.

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

Re: To free the Baltic grid, old technology is new again

#104

Post by londons_explore »

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.

Re: To free the Baltic grid, old technology is new again

#105

Post by salamandersss »

helloooooooo wrote: post #88
TMWNN wrote: post #67

Earlier quoted context omitted.

>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…

US and Canada grids are split east-west, and then there is a third grid restricted entirely to the geographic region of Texas

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.

Re: To free the Baltic grid, old technology is new again

#106

Post by chx »

rbanffy wrote: post #94
chx wrote: post #31

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 CE…

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.

Re: To free the Baltic grid, old technology is new again

#107

Post by ako »

standeven wrote: post #97
gumby wrote: post #90

Earlier quoted context omitted.

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.

Sized to fit in a car?

Re: To free the Baltic grid, old technology is new again

#108

Post by sgjohnson »

halper wrote: post #68
PartiallyTyped wrote: post #58

Earlier quoted context omitted.

I found this article from bloomberg on the event! > 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 freq…

Apologise to pick nits, but if it is not Turkey it is Türkiye. The former is perfectly fine in English.

> if it is not Turkey it is Türkiye. The former is perfectly fine in English.

Not according to the Turkish government.

https://www.theguardian.com/world/2022/jun/03/turkey-changes...

Re: To free the Baltic grid, old technology is new again

#109

Post by fuzzfactor »

adrianmonk wrote: post #42
formerly_proven wrote: post #3

> 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.

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…

>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.

Re: To free the Baltic grid, old technology is new again

#110

Post by jacquesm »

cesarb wrote: post #103
jacquesm wrote: post #93

Earlier quoted context omitted.

Yes, the water hammer from a major dam must be quite impressive if you try to contain it by main force rather than to reduce the flow gradually.

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.
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