Useless High-Voltage Power Lines Risk Sparking California Fires (yahoo.com) 22
"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:2)
Lines that are not energized should be grounded out; not sure why these were not.
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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).
Re:Ground out of service lines. (Score:4, 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.
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Moreover, you can see the fuses are open at the end of the line.
Re: Ground out of service lines. (Score:2)
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.
physics (Score:1)
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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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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?
How much electricity overproduction is there? (Score:2)
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?
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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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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.
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