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Why Does the U.S. Have Three Electrical Grids?

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Re: Why Does the U.S. Have Three Electrical Grids?

#141

Post by phonethrowaway »

Gwypaas wrote: post #88
tinix wrote: post #85

Earlier quoted context omitted.

Consider the distance, and speed of light, and the speed of electricity (1/100th of that). I don't think it's truly feasible to keep that much physical space in sync. Hmm...

Apparently not a problem to do today. https://en.m.wikipedia.org/wiki/Synchronous_grid_of_Continen...

That's not a very large area, to be fair. That's about the size of half of the United States, in distance/spread. Europe isn't a continent in the traditional sense, it's a region, and not a huge one.

This might counter the grandparent poster if Asia was on the same synchronous grid, but it's not.

Re: Why Does the U.S. Have Three Electrical Grids?

#142

Post by phonethrowaway »

Gwypaas wrote: post #88
tinix wrote: post #85

Earlier quoted context omitted.

Consider the distance, and speed of light, and the speed of electricity (1/100th of that). I don't think it's truly feasible to keep that much physical space in sync. Hmm...

Apparently not a problem to do today. https://en.m.wikipedia.org/wiki/Synchronous_grid_of_Continen...

This is a better example IMO: https://en.wikipedia.org/wiki/IPS/UPS

It spans 8 timezones.

Europe is just larger in capacity, not breadth.

Re: Why Does the U.S. Have Three Electrical Grids?

#143

Post by Gwypaas »

phonethrowaway wrote: post #141
Gwypaas wrote: post #88

Earlier quoted context omitted.

Apparently not a problem to do today. https://en.m.wikipedia.org/wiki/Synchronous_grid_of_Continen...

That's not a very large area, to be fair. That's about the size of half of the United States, in distance/spread. Europe isn't a continent in the traditional sense, it's a region, and not a huge one. This might counter the grandparent poster if Asia was on the same synchronous grid, but it's not.

I guess there's two ways of looking at it. The distances spanned by the extreme points net or how dense it is. Not that I have the knowledge to relate any of that to real world use cases or consequences.

Here's the map including all larger powerlines

https://www.entsoe.eu/data/map/

Re: Why Does the U.S. Have Three Electrical Grids?

#144

Post by thelastname »

mcv wrote: post #118

Europe's integrated power grids can very rarely cause weird problems. A couple of years ago, a dispute between Serbia and Kosovo left some power demand unfulfilled, which lead to the grid frequency slightly dropping, which caused grid-powered clocks to lose about 6 minutes: https://arstechnica.com/tech-policy/2018/04/european-grid-di... Political tension between Serbia and Kosovo is not entirely unexpected of course,…

German transfers from wind farms at the north to factories in the south and Austria often caused problems in Polish and Czech networks. https://www.politico.eu/article/germany-austria-energy-europ...

Re: Why Does the U.S. Have Three Electrical Grids?

#145

Post by crmrc114 »

crmrc114 wrote: post #70
labcomputer wrote: post #34

Earlier quoted context omitted.

> Close, Three phase systems actually are a carry over from the days of early induction motors. It's not just some historical accident. We continue to use multi-phase power because it enables continuous delivery of power (unlike single-phase, where the delivered power drops to zero at least twice per cycle). And two phases require just as many wires as three phases, with more power delivered for a given mass of coppe…

If both loads were on the same phase that would be a violation of the US NEC (NFPA 70) because use the load would be 40 amps..... And guessing we are taking 12awg, way over allowed current. In hindsight I did not specify circut ampacity, or wire gauge. Still the question stands, how much current would you read at the panel on the neutral with those two loads on the line :-) (In my example you have two phases 120 degr…

Oops should have typed 180 degrees apart for residential.

Re: Why Does the U.S. Have Three Electrical Grids?

#146

Post by alricb »

gorbypark wrote: post #135
cm2187 wrote: post #92

The argument for more unified grids would have had more leg before the 2003 outage, where a failure was propagated through the grid and resulted in a blackout for a large part of the US. With multiple separate grids, at least you reduce the impact of such event.

It also took out a large chunk of mid eastern Canada (parts of Ontario and Quebec, iirc)!

Quebec wasn't affected, it's on a separate grid linked to the rest of the eastern grid by back-to-back AC-DC converters.

Re: Why Does the U.S. Have Three Electrical Grids?

#147

Post by EricE »

fomine3 wrote: post #65
fireattack wrote: post #64

Earlier quoted context omitted.

Any "evidence" (or anything substantial) about your hypothesis? Like, did Japanese companies actually invent inverters, or are inverter air conditioners more common in Japan compared to other countries?

Sorry for bad English, "develop" would be better word than "invent". AFAIK Daikin argues that Inverter Air conditioner is very popular in Japan compared to other developed countries. In Japan, mini-split type a/c is common and almost all producs are runned by inverter compressor (except very cheap one but almost no one buy it). Here's Daikin's argument (japanese). Green is % of inverter and Japan is 100%. https://www…

My parents have an inverter mini-split. It’s amazingly effective at dehumidification. If I ever have to change out one of my AC units I will probably go with a multi-zone mini split. Being able to condition only the rooms that are in use and the super effective dehumidification the systems offer are a significant upgrade over traditional ducted AC systems. Heat pumps on mini splits tend to be far more effective too.

Re: Why Does the U.S. Have Three Electrical Grids?

#148

Post by EricE »

MrBuddyCasino wrote: post #124

Too much efficiency is dangerous: it makes the overall system more vulnerable because it removes redundancies, increasing systemic risk. Decision processes are not scale-invariant: politics, and therefore susceptibility to corruption, increases, transparency decreases. Not saying a unified grid is not worth it, but there are downsides that might not be immediately obvious.

Yup - just in time manufacturing means we often rely on critical parts delivered from foreign countries. I wish I could remember the article I read over five years ago that was pointing out that many utilities do not have backup equipment at larger substations and often rely on replacement devices from overseas sources.

Hopefully we have gotten a bit better and stockpile spares for critical infrastructure such as the electrical grid, especially when we have lost so much of our internal manufacturing capabilities.

Re: Why Does the U.S. Have Three Electrical Grids?

#149

Post by EricE »

lmm wrote: post #103
jdswain wrote: post #68

Earlier quoted context omitted.

Wouldn't a better solution be to make them all in phase with each other? Then there wouldn't need to be any HVDC interconnect.

A large grid is harder to manage and runs the risk of a cascading failure. Especially as HVDC is a lot cheaper and more efficient than it used to be, there's an argument we should actually be breaking our grids down further.

Indeed. For some reason I keep thinking back to this :)

https://www.youtube.com/watch?v=P0BD4jmTS_M

Re: Why Does the U.S. Have Three Electrical Grids?

#150

Post by 5040 »

EricE wrote: post #148
MrBuddyCasino wrote: post #124

Too much efficiency is dangerous: it makes the overall system more vulnerable because it removes redundancies, increasing systemic risk. Decision processes are not scale-invariant: politics, and therefore susceptibility to corruption, increases, transparency decreases. Not saying a unified grid is not worth it, but there are downsides that might not be immediately obvious.

Yup - just in time manufacturing means we often rely on critical parts delivered from foreign countries. I wish I could remember the article I read over five years ago that was pointing out that many utilities do not have backup equipment at larger substations and often rely on replacement devices from overseas sources. Hopefully we have gotten a bit better and stockpile spares for critical infrastructure such as the…

Of some relevance here:

Transformers that are small are often on hand and easy to swap out. But some of the bigger ones have months long lead times. The facility we were at had transformers that had a 6 month lead time from Germany to replace them and they had to be sent via boat as they wouldn’t fit in planes.

https://news.ycombinator.com/item?id=24318278

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