Off-the-wall Hurricane Rita question

Can anyone in the power generation field answer this:

I have been watching the troubles that hurricane Katrina and more recently, Rita have caused.

In Galveston, the news media tells us that fires caused by transformers exploding is causing the majority of the damage.

Why doesn't the electric utility turn off the power somewhere "upstream" of the poles? Surely anyone who would have stayed behind could not have expected to have power during the storm. Any facility that needed power to function (hospitals, for example) have back-up generators.

Not to sound at all unsympathetic, but this just doesn't make sense to me. Am I being to over-simplistic in my evaluation of the complexities of operating an electrical distribution system for an entire area?

I would think it a tremendously difficult task to select where power is not necessary. For instance, street lighting is nice, if it doesn't get knocked out, to aid fire and police, ambulance, etc. If you kill power to one area or another you might lose more than you gain. Communication is another area that needs power. If you start cutting power, you would have to ensure necessary services have generating capabilities of their own.

Another reason to leave the grid as 'live' as possible, is to allow downstream circuit protection to trip out where a fault develops. That is fairly important when the time comes to 'swich on' again, without the need for line crews to manually shut every sub-grid off prior to reconnecting the mains.

Also, don't forget the basic fact that until a storm actually hits, nobody knows for sure where or when it will. Should all of the gulf coast have been isolated?
As you live in Ohio, you know about what amount to very few actual main grids. Wasn't it an Ohio Substation that started the chain-event ripple blackout of almost the entire northeast two years ago in August?

I have to look at this from several perspectives.

Having been in the standby power field, I think that any critical application should have a generator, or something. Even a radio station, not a little 5kw to keep the tower lights lit, on big enough to keep the finals on the TX lit too! This goes for Wallymart, big Mac's, and service business that becomes helpless when the power goes off for the whole day.

From the electrical contractor side, and dealing with my lineman buddies, I am surprised that is was left on. In my area we have a lot of storms where power may be off for a day. Generally, it is up and running in a few hours. I have had a few cases where I was swapping out an electric service, and customer had to be without for an extra day or more due to no linemen being available. We have a lot of wind and Tornados around here. I am near (and from) Utica which got hit pretty bad last year.

From having been a police radio technician, Motorola tech, Civil Defense and ESDA member, weather spotter, etc- standby power is critical. Period. I don't profess to leave the power up. We had standby generators and batteries on equipment. One time when Peoria police was going to have to tear down their generator, the light company was informed, a rental generator was in place, and a portable 5kw was placed running near dispatch, with extension cords running in "just in case". At least one tech and the city radio engineer were present during the whole ordeal. All transmitters and remote receivers were not at that location.

From the consumer aspect, my mother was on oxygen, with an AC powered air pump. There was also a large oxy tank in the house, and one in my father's truck, and several little bottles. The light company was aware of the oxy pump, and it was noted in their computer for priority repair service if needed.

I don't want arcing lines out there. I think the power should be cut when everyone is told to leave Dodge (well, actually a little after the time everyone should have left).

I am not sure how all these transformers are exploding.. I saw some that had the wiring short out and arc/flash. I saw some that were a product of lightning strikes near by. And maybe some sucomb to a massive short nearby.

Around here. the utilities have fuses all over. A secondary (240 residential) doesn't, or 480 going in to a building. but the really "HOT" stuph does. Within 15 miles, I have 4 major power lompanies, and 4 municipal utilites, and a couple of smaller ones. There may be some arc on the high tension lines for a little while, but if the fuses or reclosers don't trip, a signal shows up at an alarm center, and they get it shut down fairly quick, usually by remote control.

I guess the bottom line of this ramble is, if you need power, have a generator. And kill the "mains".

regards.....casey

rdrast said:

Wasn't it an Ohio Substation that started the chain-event ripple blackout of almost the entire northeast two years ago in August?

Click to expand...

Do I know? After reading the "autopsy" of that blackout a couple years ago, I found out the plant that was the first culprit was one five miles from my house. Also, my company has some equipment there (air pollution control, not power generating).

And thanks for the insight...I guess I was being over-simplistic.

One of the reasons for not cutting the power is when it is time to bring it back on, the shorted equipment may still cause many problems.

If the power is cut, every one will think it is OK to remove the downed lines from their house, driveway or street. Unfortunately, the power could be turned on and the unsuspecting person gets killed. Whose fault was it they were handling the down line? By leaving on the power, customers can contact the utility and report outages. Then the utility can make the priority repair list and begin restoring power.

If power was removed, all lines would have to be inspected and repaired prior to powering the grid. That means EVERYONE would be with out power for up to some totally unacceptable amount of time.

Leadfoot said:

If power was removed, all lines would have to be inspected and repaired prior to powering the grid. That means EVERYONE would be with out power for up to some totally unacceptable amount of time.

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Thats reason 1.

Reason 2 is restartup of a power plant is a real big & costly deal, and may also take days. During the big North East black out we were with out power for 3 days.


Most standby power units that I'm aware of only store fuel for a few days of generating. Remember the hospitals in NO ran out after 3 days...So did the Aquarium of the Americas. Lots of dead fish & dead people.

When hurricane Floyd hit here in '99, I witnessed the light show out my front window as 3 local substations exploded within a 1 minute period. Our power went out with the first flash. It was nearly a WEEK before we got power back...

We got lucky during the '03 blackout. Right on the border. It reached the next town over, but we were on the 'has power' side...

Yes, I have a generator...



-Eric

I like Leadfoots thoughts too.

Here in Foat Wuth we have twisters and floods.
Stupid me 'loaned' my little 1hp generator- enough to power a fridge and TV and a Mac - (at least I got a Browning 22 rifle as collateral .

I can't imagine the inrush current that 20,000 air conditioners and refrigerators would require.

Rod

I was on Seattle City Light Rate advisory committee - thought I knew some stuff from having worked for another utility at Trojan Nuclear Plant. I learned even more.

First
The utility has obligation to provide power EXCEPT
non payment of bill (here in Seattle it takes court order to disconnect)
cheating the meter (no court order required)
system breakage
weather damage (crews are placed on standby here if we expect high winds)
SO
if the utility turned everyone off to prevent damage to the system
they would be in breach of contract
and the liabilty lawyers would be in seventh heaven.

not to mention all the reasons already mentioned.

Dan Bentler

rdrast said:

Another reason to leave the grid as 'live' as possible, is to allow downstream circuit protection to trip out where a fault develops. That is fairly important when the time comes to 'swich on' again, without the need for line crews to manually shut every sub-grid off prior to reconnecting the mains.

Click to expand...

This is a good point. It's probably makes more sense to just let things trip, blow, explode, etc. sporadically as the 'event' is happening. This allows the utility to keep track of what will need repair.

Let's say you turn off the power before the event. When you turn it back on, every single 'problem' shows up, ALL AT THE SAME TIME!...



-Eric

I thought the reason was to allow things to shutdown as they failed. The ultimate in smoke testing.

I stayed in Houston, with my backup generator ready to provide power for my fridges and lights.... but not my AC...

Didn't need it. People across the street lost power for about a day.. behind us for about two days (came back this a.m.), but I guess I just live right... and was prepared.

What I want to know is how the transformers know who has a back up generator, and who doesn't.

The utilities all hope things DO NOT FAIL. But, we all know things do. By keeping the grid hot, the weak links can be found.

I was in Houston last week to teach a couple of training classes. I was told to pack up and head back to Red Stick. Thursday, while in the 0 to 2 mph club on I-10 east, I was driving along side a flat bed loaded with brand new transformers that was headed for the swamp bowl. There were numerous truck loaded with goods and rebuild materials for the NO area. Kind of ironic as they were predicting mass distruction in the Houston to Baytown areas.