Nature: US electrical grid on the edge of failure

[GliderGuider]

US electrical grid on the edge of failure

Facebook can lose a few users and remain a perfectly stable network, but where the national grid is concerned simple geography dictates that it is always just a few transmission lines from collapse.

That is according to a mathematical study of spatial networks by physicists in Israel and the United States. Study co-author Shlomo Havlin of Bar-Ilan University in Ramat-Gan, Israel, says that the research builds on earlier work by incorporating a more explicit analysis of how the spatial nature of physical networks affects their fundamental stability. The upshot, published today in Nature Physics, is that spatial networks are necessarily dependent on any number of critical nodes whose failure can lead to abrupt — and unpredictable — collapse1.

The electric grid, which operates as a series of networks that are defined by geography, is a prime example, says Havlin. “Whenever you have such dependencies in the system, failure in one place leads to failure in another place, which cascades into collapse.”

The warning comes ten years after a blackout that crippled parts of the midwest and northeastern United States and parts of Canada. In that case, a series of errors resulted in the loss of three transmission lines in Ohio over the course of about an hour. Once the third line went down, the outage cascaded towards the coast, cutting power to some 50 million people. Havlin says that this outage is an example of the inherent instability his study describes, but others question whether the team’s conclusions can really be extrapolated to the real world.

[sinkingfeeling]

1. Didn't Bush promise to fix that a decade ago?

[quadrature]

2. cascading outages are a thing of the past .nt

[NickB79]

3. Does this tell us anything about propsed distributed energy grids?

Like the idea of using Great Plains wind and Southwest solar to replace fossil fuels on a national scale?

My first thought was, if the potential failure points are in the transmission lines between geographic networks, and we need to build MORE transmission lines to support a more diffuse, distributed renewable energy grid.......

[oldhippie]

4. Unfortunately, ....

I think politically, transmission lines are even harder to get approval to build than the fossil fuel plants. We had a hell of a time getting permission to build the transmission lines from the west Texas wind farms to the Central Texas markets. And it wasn't "big power" or "big oil" or big anything fighting it. It was just plain folks that didn't want to see power lines anywhere near them.

[GliderGuider]

5. That issue may be THE big one for a distributed grid. nt

[NickB79]

6. OK, so I'm not completely off my rocker in seeing that connection

Good.

Though I expect you and I will be "corrected" on it any minute now......

[GliderGuider]

7. A quick back of the envelope calculation

Example: power a city of 1 million people entirely by wind.

Average power consumption: 1400 w/person, or 1400 MW for the city.

Capacity required: 1400*4 = 5600 MW.

Total lease area required per MW: ~45 hectares (not land use, but lease size - we're calculating transmission line distances).
Total lease area required: 1000 square miles
Lay lay the wind farm out in a solid ring shape around the city, with the inner edge 20 miles from the city core. You end up with a ring of wind farm all the way around the city 10 miles deep.
Break the wind farm into 10 zones, each of 100 square miles. Collect the power within each zone and feed it on an HV line into the city.

The intra-zone interconnections would probably require 250 miles or so of lines, for a total of 2500 miles.
The city feeders would require another 250 miles of lines (10 feeders each 25 miles long)

So it would need (at least?) 2750 miles (~4500 kilometers) of mostly new transmission lines to feed a city of 1 million.
At a cost in the range of $2M to $3M per mile that looks like around around $6 billion for transmission lines - about the same cost as the turbines themselves.

Try getting that past the city planning commission.

[oldhippie]

8. Oh, poo .....

You're just being negative, using that math shit and stuff.

I'm sure Kristopher has a paper somewhere that shows it will be free and no problem at all. We should have done it already.

[NickB79]

9. Oh, that planning commission problem is easily solved

We just build the turbines a few states away in the middle of the Great Plains where no one cares!

And we, um, run more lines into the cities. Across entire states. At $2M per mile. Uh, yeah......

[pscot]

12. That shouldn't be a probllem

once the suburbs are gone.

[MH1]

17. Why would you power an entire city by wind? Are you assuming no solar?

Or that it would be insignificant for some reason?

Let's say all fossil fuels and nuclear are out of the question, for some reason. (Just being hypothetical here).

You have: wind, solar, maybe geothermal in some places (I am no engineer, just mentioning what I've heard of), plus reduction of use.

Using reasonable estimates for a dense urban area, what do you think the actual components of solar and use reduction could look like?

[GliderGuider]

18. You wouldn't. This was a thought experiment about transmission line requirements

Diffuse renewable power generation requires more transmission lines for aggregation than large centralized generation - and probably still more for load balancing. The use of solar or wind as the generation technology would make little difference to the transmission line requirements.

[MH1]

19. Hmm, are you saying that if every rooftop suddenly sprouted solar panels (grid-tied),

there would be a need to upgrade the transmission lines or other components of the distribution system? It wouldn't just decrease the draw on the centralized power plant?

(pardon my ignorance of the subject, I'm just trying to get a high-level view)

[GliderGuider]

20. No, I'm not saying that. I'm addressing a different question

Just around the transmission line requirements of large-scale renewable energy. Large manufacturing facilities for instance can't be powered with rooftop solar. They need larg-scale power, and if that is supplied by renewables it will need to be aggregated away from the plant. Same goes for 50,000-home communities that don't have rooftop solar.

The point is that if we need to aggregate wind or solar for larger-scale applications that just running home computers and some leds, we need to pay attention to the cost and political difficulties of adding to the transmission-line infrastructure. It's not an insignificant issue.

[MH1]

21. Ah, ok! Thanks.

It makes sense that industrial applications are a different problem than residential or office building.

[kristopher]

22. They aren't. nt

[GliderGuider]

23. Factories can require much higher power per square foot than single-family homes.

the same applies to office buildings and apartment complexes. That means rooftop solar can offer only a small increment of help. Bringing is enough renewable power to areas with high power density requirements from areas where it can be generated in large quantities means transmission lines.

[kristopher]

24. No it doesn't.

Your entire thread is based of false assumptions, invalid definitions of what a distributed grid is and inaccurate portrayals of how a grid of any type functions.

IOW, classic GG GIGO.

[GliderGuider]

25. So there are no new wires required to add wind and solar farms to a grid?

How would that work?

[Yo_Mama]

11. That is the contradiction in terms ignored by the standard rhetoric

It's not a slam-dunk.

We stopped cascading failures by basically more monitoring and installing cutoffs that could be used to stop the transmission cascade. High degrees of penetration with quite variable sources imply a more complex transmission system and less ability to compensate for problems. Here's a recent paper:
http://arxiv.org/pdf/1209.3733v2.pdf

I think you can prevent large cascading failures, but probably would have a lot of local failures along with pretty variable voltage. In the long run you have to compensate by cutting power.

[CRH]

10. I think the biggest failure facing the grid, ...

is the business model of the utilities that use it. It is they who must maintain the grid, yet the future is pointing toward more localized generation by individual and small corporate sources, and less in transmission. As the 'smart' grid gains efficiency, the business model of utility sponcered generation will begin to falter. There will be a period of chaos centered around who will pay for grid maintenance and expansion, as revenues in utilities decrease. Of course then, government is 'good for business', when industry decides the public should pay a second time, to support 'their' public utility.

[Yo_Mama]

13. Except that most theories on implementing renewables expand transmission requirements

Instead of lowering them. Grid operation can be very different from power generation. The question is paying for it.

Localized generation by companies and individuals only works for wind and solar if all the excess is efficiently "passed around", and that requires greater capacity and more transmission infrastructure rather than less.

All of which means that your grid charges are going to grow. The problem has been more in paying for it - or regulatory/public relation obstacles in installing high capacity lines, for example.

Let us take, for example, a theorized ruralish area in which every house was served by the grid, and in which, ten years later, every house had a grid-tied solar array designed to achieve zero net metering. In other words, each house now has a solar installation that will produce an expected amount of electricity sufficient to cover its expected requirements over the course of the year.

Would that require more transmission capacity or less? The assumption most people make is that it requires less, but that's the complete opposite of the reality. And this is why almost all rural areas in which solar starts to become built out start imposing limitations. The existing grid can't handle the power flows.

The reason for this is that almost all of the solar power produced will be produced in a six to eight hour period each day. It will vary according to season of course, but that power usually doesn't correspond with peak draw periods. So if the existing lines were capable of carrying peak demand X 2, now you have something like peak demand X 3 or 4. Grid-tied systems will cut out when local line voltage becomes too high, but of course that defeats the purpose - you are just throwing the power away.

Then if you want to use the excess power being produced in that area someplace else, you will have to upgrade the local lines and the entire local interchange to export the excess somewhere else. That's not a trivial problem, and it's not a trivial expense. In fact it has not yet been done in Germany or anywhere else.

Finally you need to upgrade the local distribution to adjust for currency fluctuations. You can do this, but again it is not a trivial expense. And there will be an ongoing expense -these components have to be replaced.

So you have the paradox of much higher grid costs, but the net metering concept leaves less people paying the much higher cost. Of course those who can install solar power do well, that is until their power supply fails or until they are forced to pay some of the cost.

It's theoretically easier to deal with wind power inputs because wind is mostly from larger installations, so you can develop a node system with high capacity lines that can shunt power from one regional grid to another. It's still expensive, but you shouldn't have the local line costs.

[Nihil]

14. Kick for the OP subject ...

... rather than the sideline that will probably devolve into the usual slanging match.

I'd be interested to hear (read) what the response of the various grid operators
is to this study.

[bananas]

15. That's why there's no internet, telephones, roads, or plumbing.

Those are all spatial networks.

From the article:

“I suppose I should be open-minded to new research, but I'm not convinced,” says Jeff Dagle, an electrical engineer at the Pacific Northwest National Laboratory in Richland, Washington, who served on the government task force that investigated the 2003 outage. “The problem is that this doesn’t reflect the physics of how the power grid operates.”

[GliderGuider]

16. Yes, it was a theoretical study. Any comment on my cost calculations above? nt

[kestrel91316]

26. The national grid is just commiesoshalist nonsense. Electricity should be

every man for himself. It's the Amurkan way!!1!!11!!!

[GliderGuider]

27. Now that's a way to distribute the grid!

Want electricity? Make it your own damn self!

[kestrel91316]

28. Don't laugh. This is what the RW wants.

[GliderGuider]

29. OK, I'll try. Hold on...

Nope, didn't work.