Useless High-Voltage Power Lines Risk Sparking California Fires (yahoo.com) 78
"A line idle for decades has been accused of starting the LA area's deadly Eaton Fire," writes Bloomberg, describing California's abandoned power lines as "a fire risk hiding in plain sight."
[Abandoned power lines] fall out of use, either because they've been replaced or because the power plants they once connected to the grid shut down... Sometimes the utilities that own idled lines disconnect them from the power grid, cutting off the flow of electricity through the cables. Other times, they don't, keeping them energized. California regulations require the companies to remove power lines they don't anticipate using again, but there's no set deadline. The companies can keep idled lines in place if they foresee needing them in the future, so long as they're regularly inspected and maintained.
Even those that have been unplugged from the grid can potentially pose a danger. The line under scrutiny due to the Eaton Fire is owned by Edison International's Southern California utility and was retired in 1971. Under normal circumstances, it carries no electricity, according to the company. Lawyers suing Edison allege that a January 7 power surge on a nearby, active line created a magnetic field that briefly re-energized the dormant cable, setting off the sparks that ignited the blaze. Edison said in a state filing that it is investigating that theory. State investigators have yet to announce a cause for the fire.
A 2019 fire that burned 77,700 acres (31,444 hectares) was started by an old power line for a plant that closed in 2001, according to the article. PG&E, the state's largest utility, "hadn't removed it, and it stayed connected to the grid, energized." [PG&E] agreed to remove 72 permanently abandoned transmission lines — representing about 260 miles (418 kilometers) of dormant cables. The work could cost as much as $268 million spread over 10 years, the company estimated at the time. PG&E had removed 64 of the idled lines by the end of 2024, according to a spokesman.
"At the right conditions, failing idle facilities can pose significant wildfire and safety risks," PG&E said in its plan to remove the equipment.
Thanks to long-time Slashdot reader larryjoe for sharing the news.
Even those that have been unplugged from the grid can potentially pose a danger. The line under scrutiny due to the Eaton Fire is owned by Edison International's Southern California utility and was retired in 1971. Under normal circumstances, it carries no electricity, according to the company. Lawyers suing Edison allege that a January 7 power surge on a nearby, active line created a magnetic field that briefly re-energized the dormant cable, setting off the sparks that ignited the blaze. Edison said in a state filing that it is investigating that theory. State investigators have yet to announce a cause for the fire.
A 2019 fire that burned 77,700 acres (31,444 hectares) was started by an old power line for a plant that closed in 2001, according to the article. PG&E, the state's largest utility, "hadn't removed it, and it stayed connected to the grid, energized." [PG&E] agreed to remove 72 permanently abandoned transmission lines — representing about 260 miles (418 kilometers) of dormant cables. The work could cost as much as $268 million spread over 10 years, the company estimated at the time. PG&E had removed 64 of the idled lines by the end of 2024, according to a spokesman.
"At the right conditions, failing idle facilities can pose significant wildfire and safety risks," PG&E said in its plan to remove the equipment.
Thanks to long-time Slashdot reader larryjoe for sharing the news.
Ground out of service lines. (Score:3)
Lines that are not energized should be grounded out; not sure why these were not.
Re: (Score:3, Interesting)
Lines that are not energized should be grounded out; not sure why these were not.
Probably because of meth heads, they can't steal the copper if the line is live (though they will try).
Re:Ground out of service lines. (Score:5, Informative)
Power lines aren't made out of copper, they are made out of steel-reinforced aluminum (ACSR). Copper is too heavy and too expensive to be practical to use for long distance power lines.
Re: HEY YOU FUCKWITS (inc. fag rsilvergun -Damien (Score:2)
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Moreover, you can see the fuses are open at the end of the line.
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Thanks. Can you explain why they aren't buried, or at least designed in such a way that if they break they immediately de-energize and don't start a fire?
I'm guessing the answer is cost, but you would think with the recent massive fires and insurance pay-outs the economics of that would have changed somewhat.
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In western europe HV power lines (except the 6 digit voltage ones) are generally buried in cable guides within city limits and expecially within housing areas. Clearly the US - or california anyway - doesn't believe thats important.
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I think you are mixing something up.
6 digits means 100,000V to 999,000V
You do not have that in rural areas. That is an overland line long distance transport grid.
Which is usually on poles.
AFAIK the highest voltage level in towns / cities is 36kV ... and that is already distribution grid for consumers who actually need power in the rang of 5kV to 20kV.
Those are mostly buried, yes. But not all.
For reference, the tram grid is run by 500V DC lines....
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"6 digits means 100,000V to 999,000V"
Well done, have a maths badge.
"You do not have that in rural areas"
Umm, thats EXACTLY where you have them.
"Which is usually on poles."
Poles? What 3rd world shithole do you live in? They're on proper 100 foot high pylons here in the UK and most of europe.
"For reference, the tram grid is run by 500V DC lines"
Random irrelevance.
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An area with 100kV lines is not urban.
Sorry.
And if I say pole, then because the term Pylone was not in my mind at that moment. Wow, what a hypocrite.
So, you want to tell me, you live in Europe, and have 100kV lines underground - in a city?
So, I mixed up rural and urban - you claimed in urban areas everything is underground, even 6 digit voltage lines. We do not have lines with that voltage in cities ...
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You do know that some of the power transmission facilities in California are longer than some western European nations, yeah? The Pacific DC Intertie alone is over 1300km long (otherwise known as 30% longer than France is from its furthest northern point to its furthest southern point) and carries up to 3GW and started construction in the 1960s, finishing in 1970. And that's only one of them - there's also Path 27 (2.4GW) which runs from Salt Lake to Los Angeles (780+ km).
But these apples look totally dif
Re:Ground out of service lines. (Score:5, Informative)
HV power lines are very expensive to bury. They go long distances don't benefit from co-locating services such as in your neighborhood where at some point the entire area was dug up to install all manner of storm water, sewage, telecoms, etc. You find the same thing with long distance utilities, as soon as you get outside of the suburb boundary you'll find water mains and sewage pipes are run above ground too.
As for de-energising, there's three technical points.
1) How do you detect a break? What's the difference between a broken line and a line without any current flowing over it? Measuring 1A on a line designed to measure 100s of amperes is difficult. If the line hits the ground there may be current going to earth at which point you are still measuring current. The only truly reliable way to do it is time domain reflectometry which is insanely difficult and expensive to do live. We actually do already have differential tripping system where we open the breakers if there's a difference in measured current between both ends of the cable, but that leads us to the second topic:
2) What causes a line to break? In most cases where the issue is foliage the arc causing a fire occurs before the line breaks. In that scenario the power is isolated but the damage is done, the tree is already burning. HV power isn't like the spark in your power outlet. It's hugely devastating, insanely hot, and what it doesn't vaporize it sets on fire (youtube has a few good videos showing what happens when people throw sticks at HV power lines).
3) The final part isn't typically done in HV, but rather in LV, which can be just as bad for starting fires, especially in smaller lines going out to tiny towns, suburbs farms etc: Reliability. The assumption is that something will go wrong in a transmission system, and that this something may cease existing when it happens (think a bat stretching across two wires causing a short, or a branch of a tree falling on the line). In order to ensure reliability of supply some lines include auto-reclosers. These are circuit breakers which recognize that this bat (now on fire) is probably going to burn away in a few seconds allowing the power to go back on. They will attempt to re-energise the power line a few times automatically (blowing up whatever it shorting them out) before they give up and alert a maintenance crew. Sounds bad, but if you've ever had a 2minute power outage before you can thank an auto-recloser for it not being a 2hour outage.
Re:Ground out of service lines. (Score:5, Interesting)
I get that the cost of burying them is high, but compared to the cost of the wildfires?
Or is this some capitalist thing where the power company doesn't end up paying for the massive destruction caused and therefore has little incentive to spend extra money burying infrastructure?
Re:Ground out of service lines. (Score:4, Informative)
Well that's why PG&E is spending shitloads of money to bury ~800 miles of transmission line [pge.com]. Because they were finally held accountable for a huge fire that caused billions in damage, started by their overhead transmission lines that were not maintained and had steel hangers for the wires that were sawed in half from "fretting erosion" [nbcbayarea.com] and never inspected or replaced.
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I get that the cost of burying them is high, but compared to the cost of the wildfires?
That is a multi-variate question in conjunction with a whole lot of what-ifs and crystal ball dynamics. The question isn't bury vs have a wildfire. The question is bury vs install up high, neglect maintenance for decades allowing trees to encroach lines, don't properly decommission lines, experience power surges at precisely the right time, and do it all while extremely unfavorable weather can promote a devastating fire.
You're in the territory of predicting natural disasters here (since weather was a contri
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Power lines aren't made out of copper, they are made out of steel-reinforced aluminum (ACSR). Copper is too heavy and too expensive to be practical to use for long distance power lines.
While true, aluminum and steel both have scrap value as well. They might not get as much as for copper but its still something they can and would sell.
Re: Ground out of service lines. (Score:1)
High Voltage lines aren't typically "easily accessible", they are typically up on towers, not utility poles running thru neighborhoods.
If meth heads were trying to scavenge the wire, I think we'd see reports of meth heads dropping to their death from towers...
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If meth heads were trying to scavenge the wire, I think we'd see reports of meth heads dropping to their death from towers...
It's not a frequent occurrence, but it does happen. I remember an article several years back here in Florida of some idiots who thought it would be a good idea to steal wires from the utility poles. Spoiler alert: it ended badly for the would-be thieves.
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High Voltage lines aren't typically "easily accessible", they are typically up on towers, not utility poles running thru neighborhoods.
If meth heads were trying to scavenge the wire, I think we'd see reports of meth heads dropping to their death from towers...
Uh, how many other meth-ods of death have you seen reported?
If methheads were dying from cannibalism, most of mainstream society wouldn’t have a damn clue. Never seen a single report on the news. We simply know they just die off. Somehow.
Re: Ground out of service lines. (Score:5, Funny)
It's the vampires. It used to be that a vampire, if he/she were careful, could just kill some rando every now and then without attracting attention. That started to get harder to do about a century ago. Vampires very nearly went extinct in the Western world because it was harder for them to cover their tracks. Even a big city like New York can only have so many missing persons and unsolved murders before folks take notice. But then harder drugs got into the mainstream, and a steady supply of "disappearables" - folks who could go missing and no one would notice - started up again.
The only downside for the vampires is that they're now tweaking like mad. That explains their fashion choices, anyway.
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Re: Ground out of service lines. (Score:1)
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Lines that are not energized should be grounded out; not sure why these were not.
Probably because of meth heads, they can't steal the copper if the line is live (though they will try).
This week, on California NeoGraphic..
(Narrator, ala Attenborough) “And we see here, the elusive methhead in its natural habitat, foraging for..”
* BZZZZZIZZIZZZZLE-ZIZZZZ-ZIZZZZZ-POW *
(Narrator) “Ah! It appears this methhead has developed a unique cooking method. They can run quite fast too, running ‘round like that on fire. Quite a lovely color of flame, if I do say..”
Re: Ground out of service lines. (Score:1)
Meth heads stealing the lines for scrap seems like a win-win for the "remove a potential fire source on the cheap" problem.
Or, if we insist the utility does it all, they could start prioritizing the segments closest to energized lines and go back later for the isolated segments too remote for this induction risk to arise.
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Meth heads stealing the lines for scrap seems like a win-win for the "remove a potential fire source on the cheap" problem.
Guess that depends on if methheads read signs. Like ones that read “live wire”.
A methhead running around on fire, IS the fire hazard.
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If the power lines have not been used in two decades and there is no plans to reactivate them, why would it matter if the meth heads steal them? If those lines had a *lot* of scrap value, the power companies would recycle them. But clearly the scrap value is worth less than the labor it would take to recover them, so arguably the meth heads would be doing the power company a favor, albeit at considerable risk to their own lives.
In all seriousness the state should do is levy an excise tax on inactive power l
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Then they become lightning rods. Despite the grounding, a risk of strike, conduction, and current flow leading to fire hazard exists.
Take them down or maintain them. Is California really this broken? Well, I should not ask that.
physics (Score:2, Interesting)
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physics / engineering answer: no idea what the theory is or how plausible it is.
lawfare / social engineering answer: Why go to Vegas when you can gamble on suing an "evil corporation" (especially one that's practically a state owned enterprise) instead ? What are the chances that a jury will believe PG&E's "experts'" mumbo jumbo excuses? These people have profits! And they charge money! Pretty clear they're guilty.
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physics / engineering answer: no idea what the theory is or how plausible it is.
lawfare / social engineering answer: Why go to Vegas when you can gamble on suing an "evil corporation" (especially one that's practically a state owned enterprise) instead ? What are the chances that a jury will believe PG&E's "experts'" mumbo jumbo excuses? These people have profits! And they charge money! Pretty clear they're guilty.
Betting on Guilt, is not the challenge here.
Go ahead. Tell me the odds and how much you’re laying down on Punishment.
ACTIAL Punishment.
Yup. Thought so.
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I'm saying it's not about Punishment, it's about extracting dollars, especially for lawyers. In the large PG&E is close to a zero sum game since everything is funded by ratepayers.
These CA fires are due to fuel load, geography, and winds and are just going to happen. The specific ignition event almost doesn't matter.
In the 1700s, for example, an estimated 4.5 million acres burned each year, on average. This is more than four times the average annual amount of acreage that has burned in recent decades, due in large part to the state’s focus on suppressing wildfires.
https://lao.ca.gov/Publication... [ca.gov]
Systemic mitigation is an ongoing thing (see above for the current state of efforts in CA) and it's already highly regulated and legislated and PG&E
Re:physics (Score:5, Informative)
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>"The live and disused lines presumably run closeish and parallel to each other at some point (e.g. when they reach the power plant). Current spike on the live line could induce a current spike on the disused line"
Yes, it is possible, although I doubt the lines are close enough to create enough charge to do anything (like arcing), especially on just shorts runs. But if the line is de-energized, wouldn't it be trivial and cheap to just open every fuse down the line so there is no chance that can travel
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You need more than a magnetic field though. You need conductive material and relative motion. And if the magnetic field is big enough to bridge a 3m air gap at sufficient flux to create voltage high enough to start a fire, well holy fuck. What is that doing to your brain chemistry and body that is full of electrolytes.
Re: physics (Score:3)
Re: physics (Score:2)
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100mph winds may have provided movement.
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If this occurs it is essentially an act of God and Edison should not be liable for an act of God..
Something such as a nearby lightning strike can induce significant voltage in ANY long piece of metal. Including unused wiring, including In-use wiring or unrelated wiring such as ethernet cables or coax that doesn't normally carry significant voltage. Also including random metal objects such as the guard rails along an interstate. A direct hit would also energize them and create a shower of sparks th
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So, the lines themselves are steel conductors. This makes them susceptible to electromagnetic flux.
You could have an inductive coupling happen from a nearby energized wire that experiences a power surge. That is what is being posited by lawyers. Whether or not they can prove that it was enough to cause the line to spark and start fire is another thing.
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You could have an inductive coupling happen from a nearby energized wire that experiences a power surge.
In theory. It's the principle that allows a transformer to work. The problem with this idea is power lines are not wound tightly close together in parallel over long distances like in the turns of a transformer coil. Instead power lines are run w/feet or more average separation; so there is minimal interaction due to distance and any induced currents will be a tiny insignificant amount compared t
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What if there is chronic oversupply of electricity in the lines and corona discharge becomes an issue in energizing nearby lines?
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Corona discharge can be an issue, but this is just an effect of ionizing the air - the energy losses are in the form of heat and light. It does not impart significant current or charge into nearby lines. Just a few volts. Corona discharge will create a sufficient charge to destroy sensitive electronics, but not enough to power anything,
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Pretty unlikely. And that would not result in the sudden voltage spike needed here.
Re: physics (Score:2)
How close together do these cables have to be to each other and what kind of voltage level can be induced this way? Are they running energised and inactive lines together? Where were the sparks between and how much voltage is required for that?
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How close together do these cables have to be to each other and what kind of voltage level can be induced this way
You have to know which specific lines are involved, and they are still investigating this. No specific lines or location has been identified. Power transmission cables are required to have separation from one another, and the number of feet separation specified is dependent on the voltage. At a minimum several feet of separation is required, and for example at 750 kV they should require 3
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Or whether or not that constitutes fault/negligence. This is act of god territory if that theory holds up
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Material does not need to be magnetic for this effect. In fact, it works perfectly fine with copper.
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Re: physics (Score:2)
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What happens when you move a conductor through a magnetic field? Or, induce the magnetic field through the conductor?
I see lrwe answered this, but piling on is par for /.
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It is called "electro-magnetic induction". You know, Physics 101.
How much electricity overproduction is there? (Score:1)
If they're using unused parts of the grid to store excess production and still producing even more power so that it surges and the lines are so overloaded that they corona discharge, why are we still talking about energy scarcity?
Re:How much electricity overproduction is there? (Score:5, Informative)
That's not how any of this works.
Unused parts of the grid can't store energy - these unused CONDUCTORS can not store power.
Power surges are uncontrolled releases of power - think when a capacitor array meant to smooth out power ripples fails short and suddenly discharges everything it had stored.
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When they whine about transmission losses, are they ignoring the fact that they've got way more electricity in the grid than they need to satisfy demand? Why would capacitors fail unless there was oversupply (see dialectric breakdown)?
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Why would capacitors fail unless there was oversupply (see dialectric breakdown)?
Capacitors do not address oversupply, they do not store significant amounts of power. They are used for power factor management since a significant portion of grid loads are inductive. Additionally capacitors can fail for a variety of reasons including chemical breakdown even when completely disconnected. Dielectric breakdown isn't the only reason.
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"Why would capacitors fail unless there was oversupply"
Capacitors fail just aging while not installed in electronics.
"When they whine about transmission losses, are they ignoring the fact that they've got way more electricity in the grid than they need to satisfy demand?"
If we had a glut of power supply, we wouldn't still be having rolling blackouts. Try again when you live in the state, understand power generation, and how the utility grid works.
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What fucking capacitors are you blabbering about?
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Grid capacitors are not designed to smooth out power ripples, they are designed to correct power factor on a system that has a significant amount of inductive load on it. Smoothing power is done with either batteries (new), or momentum of spinning heavy machinery (traditional) such as a steam turbine itself. The stability is maintained by the momentum of lots of generators and consumers on the grid working in tandem (think of 10 people pushing a car, if one person stops the car doesn't suddenly stop moving)
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"Grid capacitors are not designed to smooth out power ripples, they are designed to correct power factor on a system that has a significant amount of inductive load on it."
Inductive loads cause power ripples and will fuck with things.
Protip: 220 and 500kV cap grid arrays for the new Brightline train to Vegas - I helped design them to combat that exact issue.
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That's probably what happened, they kept cramming more and more electrons into a few runs of wire setting up a growing magnetic field until they ran out of room, then at some point the magnetic field collapsed and the back EMF caused arcing.
All they had to do was connected a 5-cent 1N4148 snubber across it and it would never have happened. Maybe someone could point this out to the lawyers suing Edison. I'd be happy to act as a self-proclaimed expert witness for them.
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Your "self-proclaimed expert" testimony would be laughed out of court before you could even sit down.
I understand the absurdity of putting a diode on a high tension line, but the legal staff would not. The court room would be full of blank looks and vacant stares from those who see electricity and most of science as voodoo magic talk. They would only laugh once a couple of paid experts told them it was ok to do so. Not much different than most of the trolls around here.
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Your "self-proclaimed expert" testimony would be laughed out of court before you could even sit down.
I understand the absurdity of putting a diode on a high tension line, but the legal staff would not.
An “expert” testimony isn’t one when it’s bitch-slapped down by the prosecution armed with a 18-year old apprentice electrician and the NEC code book. This is a legal case involving billions in damages, not an illegal lemonade stand. Only thing absurd is your assumptions on legal tactics.
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Indeed. Now we wait for the sarcasm-challenged idiot that does not get it.
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You cannot "store" energy in the grid. You can only store it in the spinning of the generators connected to the grid. And for that the lines need to be used, not unused.
can anyone explain the math here? (Score:2)
can anyone explain how it would cost $1.03 Million to remove a mile worth of cable when it cost 300-400K to install a mile of HV cable?
re- $268 million cost and 10 years to remove 260 miles of cable.
Tip - Just tell people there is copper in those lines, they'll be gone by sunrise. (yes, i know HV lines don't have copper... but the thieves might not know better)
a cable that was abandoned 54 years ago is still on the list of "anticipated to be used" again lines... that is some ever hopeful thinking... bet th
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Well,
that is simple, in gods own country, when a mile of cables get installed, they are not under power.
When cables get dismantled/removed they are under high voltage.
This is because of the countries unions. They forgot to write anything about removal into the union contract.
And as you need a way to get rid of the to many workers you have who do nothing, and as uneducated as they are: you instruct them and train them and certify them how to safely remove a cable under power and when the flash and bang comes
CA Not Good With Utility Maintaince (Score:5, Interesting)
What it comes down to is: preventative maintenance. In New England, they know that if they don't check it in the Spring and Summer, they will have to fix it in the snow, in the freezing rain. In California, the weather is usually good. They know that they can probably fix it any time, so they don't do enough proper maintenance, and let if fail--sometimes with deadly consequences.
I understand (Score:2)
"Waste" ROI on maintenance, esp. removing things, when we can just move on and ignore them, since there's no laws forcing us to do the maintenance?
Power company needs to be de-privatized.
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Except I thought we already had legislation in place that separated the energy generation charges from the transmission charges on everyone's bill?
Consumers were supposed to have the opportunity to choose from multiple options for who to go with for the power generation (supplier) but usually have no say in the transmission portion.
Seems to me that's where the real problem lies? There's no competition for who people pay to maintain the transmission lines.