16 replies to this topic

[eds]

The largest supply chain in the world, the Grid
. . . wastes 2/3 of the energy it creates and
. . . has only 33 minutes of Storage!

When one cable in a network short-circuits,
. . . others nearby will automatically pick up the burden.
. . . But if the surrounding cables are also overstressed, they too can fail,
. . . causing a cascading effect that can knock out major portions of a network.

In recent years, the U.S. power grid has become
. . . increasingly prone to such interruptions.
Average temperatures have risen, homes have gotten bigger, and
. . . so have air-conditioning demands.
Thanks to our technology-rich lifestyles and
. . . the inefficiency of our buildings and power plants,
. . . Americans consume, per capita, at least 50% more electricity annually
. . . than the citizens of Europe and Japan.

Former Energy Secretary Bill Richardson has explained the problem this way:
. . . “We’re a major superpower with a 3rd-world electricity grid.”
The average age of the equipment that makes up our grid infrastructure
. . . is more than 40 years, and many components were designed and
. . . installed before World War II.

Source: flowcharts.llnl.gov  Storage  Con-Ed

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[Shortpoet-GTD]

To put things in perspective, the congress did spend a lot of time last year renaming post offices, and with
all that busy work, they can't be expected to do any "actual" work; like addressing the failures of our aging grid.

I know last summer was a bit scary; seeing all those sagging lines around town from the demand overload.

[Besoeker]

eds, on 10 May 2013 - 02:50 PM, said:

The largest supply chain in the world, the Grid
. . . wastes 2/3 of the energy it creates and
. . . has only 33 minutes of Storage!

When one cable in a network short-circuits,
. . . others nearby will automatically pick up the burden.
. . . But if the surrounding cables are also overstressed, they too can fail,
. . . causing a cascading effect that can knock out major portions of a network.

Normally overcurrent protection would operate before conductors were stressed to the point of failure.
But you have a valid point. If the increased loading can't be handled by alternative routes then large sections may have to be shut down resulting in serious disruption.

eds, on 10 May 2013 - 02:50 PM, said:

In recent years, the U.S. power grid has become
. . . increasingly prone to such interruptions.
Average temperatures have risen, homes have gotten bigger, and
. . . so have air-conditioning demands.
Thanks to our technology-rich lifestyles and
. . . the inefficiency of our buildings and power plants,
. . . Americans consume, per capita, at least 50% more electricity annually
. . . than the citizens of Europe and Japan.

It isn't just in the US that the power grid is struggling to meet demand.
It's a similar story here in UK. Nuclear power stations that used to supply around 19% of electrical energy are being taken out of service having reached the end of their designed life. All but two reactors will be gone within the next decade.
Nuclear is not a vote winner and successive governments have taken no action to replace lost capacity until recently. Too little too late I fear.

Ironically, we import from France which is about 70% nuclear generation.

[still learning]

Besoeker, on 11 May 2013 - 08:19 AM, said:

Normally overcurrent protection would operate before conductors were stressed to the point of failure.

Looks to me like that part of the original post in this thread is copied from the Grist article linked to in the original post.  If you read the Grist article and have an electrical background, some of it tends to induce eyerolling.  The original author seems to be one of those folks who characterize any electrical fault as a "short circuit," since they've never heard of an open circuit or any other kind of fault.  Just have to accept that most journalists don't have a technical background and don't pick things up very fast either.  It gets printed or broadcast or posted, that's good enough for some.  .

[Besoeker]

still learning, on 11 May 2013 - 04:29 PM, said:

Looks to me like that part of the original post in this thread is copied from the Grist article linked to in the original post.  If you read the Grist article and have an electrical background, some of it tends to induce eyerolling.  The original author seems to be one of those folks who characterize any electrical fault as a "short circuit," since they've never heard of an open circuit or any other kind of fault.  Just have to accept that most journalists don't have a technical background and don't pick things up very fast either.  It gets printed or broadcast or posted, that's good enough for some.  .

Yes, I had noticed that the OP doesn't appear to have an electrical engineering background but I didn't think it would be constructive to correct him/her on a matter of detail.

I post also on an electrical forum and you'd think members there would get it right but I see quite a number of basic errors from those I think ought to know better.

[still learning]

Besoeker, on 12 May 2013 - 12:47 AM, said:

Yes, I had noticed that the OP.....

My observation was mostly about the author of the Grist article, not the originator of this thread, since it looks like a lot of the original post was copied from there.
That article was presumably written by a professional journalist, or at least an aspiring journalist.  A persons' professional output is fair game for critical comment, in my opinion anyway.  There actually are journalists and authors who can write interesting and accurate articles on technical subjects intended for a general audience.  Takes some care though.   Some of the stuff from Grist is very well done, in my opinion, but some is badly done.  In this particular instance most of the article looks fairly good to me, but parts should have been edited out.

[Besoeker]

Shortpoet-GTD, on 10 May 2013 - 04:12 PM, said:

I know last summer was a bit scary; seeing all those sagging lines around town from the demand overload.

If the grid is barely coping now, it could get worse if EVs become main stream.
This is not a criticism of EVs. Just acknowledgement that they will potentially be another load on the beleaguered system
I have mentioned this before in other threads that this a constraint that hasn't, as far as I'm aware, been addressed in any meaningful way.

Either we need off-grid charging or we need to beef up the grid. The latter would be hugely costly.
Off-grid could be solar or wind.......again far from cheap.

For UK it would be in the region of £20k ($32k) to get a system that could  recharge an EV in around 24 hours.
I've based this on suppliers' websites. They want the sales but need to be honest in what they claim. Naturally, there are caveats.
I also looked at average insolation (average annual kWh/m²), PV efficiency, and come to about the same conclusion.

You also need the space to fit PV panels. Flats (apartment buildings) in densely populated cities would be a bit problematic.

It's a thorny problem but one that needs to be resolved for EVs to go main stream.

[Besoeker]

still learning, on 12 May 2013 - 03:24 AM, said:

My observation was mostly about the author of the Grist article, not the originator of this thread, since it looks like a lot of the original post was copied from there.

I don't think I've seen the Grist article.
Got a link?

[still learning]

Besoeker, on 12 May 2013 - 07:22 AM, said:

.....Got a link?

In the original post:    Con-Ed

[Besoeker]

still learning, on 12 May 2013 - 08:19 AM, said:

In the original post: Con-Ed

Appreciated, thank you.
Not a brilliant article.

[eds]

The State of New Hampshire has power provided from coal, Nuclear and Hydro,
. . . but every year, if we have ice storms, the power to the whole state goes down,
. . . for a week or more.
They say it's trees knocking down wires,
. . . I don't know the electrical reason why the whole State goes down
. . . but it does.

Everyone has to get out a gasoline generator and
. . . the roaring noise goes on 24/7 with trips to find a gas station with lines
. . . to fill 5 gallon cans of gas.

They say that solar energy with batteries are getting cheap enough to
. . . provide the same power as a gasoline emergency generator.
I just need enough to power the well water, hot water heat, and keep food from spoiling.
. . . I don't want it permanently attached to the house, I need it mobile,
. . . plug-N-Play modules that can start out small and grow,
. . . but most importantly, it's got to be affordable.

[Besoeker]

eds, on 12 May 2013 - 01:03 PM, said:

The State of New Hampshire has power provided from coal, Nuclear and Hydro,
. . . but every year, if we have ice storms, the power to the whole state goes down,
. . . for a week or more.
They say it's trees knocking down wires,

Maybe the services at local level need to be underground.
Here, in UK, our supplies at local level, even for industrial plants, is mostly underground.
The supply to our residential area is 11,000V and transformed down to 400/230/50Hz with a relatively local 1150kVA ONAN transformer. Our offices have a similar arrangement.
None of those transmission services are above ground.

We do have overhead lines at 33kV and upwards but they are on pylons at much higher elevations than trees.

That said, we are probably much more urbanised than New Hampshire.

[eds]

In NH, we have pylons on trails, that are keep clear, without any problems.

On the streets, the local utility doesn't charge for putting wires on overhead poles,
. . . but makes you pay extra to put them underground or dig them up.
. . . Some streets have both overhead poles and underground,
. . . so when the ice storms come, everyone loses power.

[Phil]

Sounds like some main feeders are getting knocked out.  The whole state seems weird though.  We had a similar situation up in the northern Washington, the subdivisions even in the sticks were I live are buried but the main feeder is overhead along the main highway.  When a tree or car crash knocks the power out the entire region is gone.  We had a bad storm a couple of years ago where power was out for a week, that was what prompted me to add battery back up to my system.

Night charging of EV's is not an issue, particularly with smart charging that the car companies are building in.  Many of the day charging stations at malls, etc. are being powered with solar so they won't appreciably affect the grid.  I would assume that solar will make more inroads, keeping pace with EV penetration.  My guess is they will balance each other out.

One of the wonderful things solar does is offload the grid during the time when it needs it the most.   Those hot August afternoons when everyone's AC is humming is also when solar is cranking out.  Thanks to my solar panels and one other house near by, the load coming out of our subdivision is as little as two thirds what it would otherwise be.  If all subdivisions were like this, the grid would gain an extra 30% or so margin.  With hydrogen/fuel cell backup replacing batteries and solar on the roof, the grid could be substantially offloaded with decent penetration.  The only issue would be urban areas where solar cannot effectively penetrate.

Personally I'd rather use funds to accelerate the future rather than prop up the past, incentives for home hydrogen generation/backup.  Works for me anyway!

[Shortpoet-GTD]

Some progress being made through meters and efficiency-

http://smartgrid.iee...ly-as-scheduled

[Shortpoet-GTD]

Maps of coal plants, natural gas sites, nuclear plants, hydro, wind, solar; and the pipelines.

http://blogs.smithso...nteractive-map/

[Phil]

Nice maps!  I see that Washington state has one coal plant, I'm surprised they have even that with all the hydro we have!  Looks like one nuke plant as well.

Even out in the boonies where I live, all meters are remotely read, no meter men.  They do have a program where you can volunteer to have your loads controlled by the utility, (AC, heat, appliances, etc.), for a reduced rate.  I didn't bother since I have solar.