The power grid and wildfires.

PG&E may cut power again due to the threat that high winds could spark a fire if tree branches damage lines.

The obvious solution is to bury lines, but it is extremely expensive. What about running the lines through heavy steel conduits on short steel posts a few feet off the ground, say six feet. The conduit could be durable enough endur impacts by tree branches. Could this work?

Not really.
The high tension power lines are really high voltage - like 300,000 volts. That requires large spacing between the conductor and anything grounded (like your conduit) to prevent arcing. The spacing would have to be very large to account for wire sag under load. So encasing the power line would require conduit the size of a culvert.

Most of the lines which service the rural communities in northern California would not be in the 300 KV range. Those are relatively few and can be defended. The ones which which cause problem when they snake through the forests are more like in the neighborhood of 12 KV, or maybe more, but they must be low enough such that the discussion regarding burying the lines never raises the question raised by beowulff regarding arcing or sagging. The only question raised is always cost, so if a line can be buried in the earth and be properly insulated, it should be possible above ground as well.

Not really, no.
Easier than this would be to just make the length of the wires shorter – put power poles closer together. That reduced the chances of wind blowing wires to touch each other or touch tree branches, etc. But that means many more power poles to be installed & connected, which is also expensive.

The cheapest option seems to be simply trimming trees that are close to where the power lines run. That just seems like normal maintenance. Our power co-op does it every 2-3 years on our farm, trimming tops on windbreak evergreens in the ditch under the power lines.

But apparently PG&E doesn’t believe much in doing ‘normal maintenance’.

Corporate directors were busy awarding themselves fat bonuses and bribing regulators - why waste the money on maintenance?

I call for all PG&E directors and senior managers of the past decade who skimped on maintenance, and all state PUC regulators who allowed such negligence, to be tried for contributing to the deaths of those killed in powerline-related fires, and for their estates to be confiscated. Painful executions might also deter future sloppiness.

We’re now almost four hours past the announced power shutoff time. They’re running late.

One big problem is who is going to pay to trim around the power lines that are going through rugged/wild property, especially when there is no designate owner.

Of course not - that would cost money.

The cheapest option, and the only one that will have immediate impact during this high-wind period is cutting power.

No, that’s still on the electric company. They established the easements through that property, so they have to maintain the trees to not only protect their lines but the surroundings.

I’ve seen third-world power lines that actually just lay on the ground. About a foot in diameter (30cm) with all insulation.

I didn’t find out any more information.

Umm, the problem isn’t powerlines. It never was.

The problem is that the way the forests are being managed, they are allowed to build up fuel and build up fuel and build up fuel.

This is the same as putting down flammable materials all around your neighborhood, year after year, until the place will explode and destroy the whole place if one spark falls on it.

And then if a person sets the place on fire, they declare bankruptcy and pay a few thousand bucks tops (or go to prison for the maximum of their life), but if a corporation accidentally sets the fire, they have to pay up to 30 billion and can’t afford another such incident.

So they turn off the power and do hundreds of millions of damage to other people as a result. (but apparently don’t have to pay for that)

One valid solution is to have logging companies clearcut off firebreaks all throughout the state of California. Probably cut about half of all the trees down. Leaving the forests as isolated, separate sections that when they catch on fire burn only that section down.

It is not a valid solution to try to prevent all sources of ignition. This is because the longer a fire is prevented, the more flammable material builds up, and the worse the eventual fire is going to be. Also, the more sensitive it will be to a spark.


Much of California has an excellent climate for tree growth, and much of what grows each year will eventually burn. It’s convenient to blame PG&E as the source of ignition, but you certainly don’t need power lines for that.

I visited Sequoia Park last year. On display at the Visitor Center is the cross section of a 1000+ year old Giant Sequoia tree. It shows evidence of many significant fires, with an average interval of 13 years. This species of tree is adapted to fire: fire damage is tolerated well, seeds need fire to sprout, and sprouts need fire-cleared land to grow. This adaption is clearly a consequence of frequent fires over at least many hundreds of thousands of years.

Well duh. The normal layout of California power supply is risky, trees grow into powerlines. In litigious America, people sued the power company for causing fires. The obvious result is “fine, we’ll cut power whenever we see a hint of risk, rather than spend money on lawyers and settlements”. I guess the real question is how much an aggressive tree control campaign would cost, and how much that adds to electrical bills - followed by “why should we pay more here in the fields when the people with tree problems are up in the hills?”. Certainly the people in the cities don’t want to pay for the people in the countryside. The people living in the hinterland don’t want to pay triple their already high electrical bills.

There’s that scene in Life of Brian when after listening to an ex-leper complain (about being an ex-leper cured by Jesus so he can’t beg any more) Brian says “there’s no pleasing some people”. The leper replies “Yes, sir, that’s exactly what Jesus said, sir!”

That is NOT a valid solution IMHO.

Managing fuel loads is certainly the right approach( or at least part of a balanced approach )and a historical failure to allow natural burns has greatly contributed to the problem by creating unnaturally dense fuel profiles. California has a Mediterranean climate and is adapted to burn. The old policy of suppressing fire wherever it pops up has had an unhealthy impact on many CA ecosystems. We need a lot more carefully managed proscribed burning. Less climate change would also be a nice as long as we are pining for ponies - our increasingly abbreviated winter season is not helping matters.

But clear-cutting half the trees in CA is, to borrow a phrase from the late Frank Zappa, like treating dandruff by decapitation. For one thing the next time torrential winter storms hit an awful lot of CA would slide into the sea in one huge mass of mudslides. Vegetation is necessary for humans beyond aesthetics. The problem is how to manage the human-wildland interface and there aren’t any easy solutions.

Most of the time, the lines arent running thru forests. They are in rural or even suburban areas.

Well. The problem is at this point if you try to set a portion ablaze for a controlled burn it is going to spread out of control for many miles.

So you would need to section the forest into separate sectors. Maybe cutting half the trees is too many but these firebreaks have to be quite large to minimize the chance of high winds carrying embers far enough to start the next sector burning.

And logging is better for the carbon footprint than burning since the wood goes into durable structures. Eventually when those houses are demolished the pieces then go in landfills, sequestering the carbon away.

So logging and also higher density housing- people shouldn’t have their homes inside the forests. Two things Californians hate.

If your going to cut 50% (which seems a little excessive). You should probably remove 50% of the basal area by diameter class, which works out to removing a lot of the little trees and less, but some, of the big trees. It would reduce the ladder fuels keeping fires low to the ground and reduce the likelihood of uncontrollable crown fires. It would also treat 100% of the area and pay for itself:)

But that doesn’t really solve the problem of the brushy areas.

Other than that it would upset the chemicals crowd, the right of ways should probably be kept so short they can spray them from a truck or ATV.

Well that sounds expensive. Clear cutting is cheap. Also fixes the brushy areas because once you split Into separate sectors you can set a sector on fire and clear it all out.

Cheap is not always better or even acceptable. Something I once remarked to very frugal friend of mine as I picked a chunk of random plastic out of an awful-tasting bit of curry chicken from a super cut-rate Chinese buffet he favored :).

In areas where the fuel load is not yet over the top or has been corrected, managed controlled fires( which also serve to activate the fire-adapted seed bank and add a proper ecological succession to wild lands )are usually going to be the best solution for maintenance.

In areas where they are out of control, mechanical thinning of the underbrush, not clear-cutting forests( which should be managed for posterity and good economics )is probably the best practice. That is very time-consuming, labor intensive and often costly. But hey - that’s why you, I and everyone else in this country is happy to pay more taxes :D!

The firebreaks would have to be extremely large. Highway 101 is a pretty big firebreak, and the fire jumped it last year. 60 mph gusts (which we are seeing now) is going to blow embers across any practical firebreak.

Expensive? Damn, if they gave it to me I’d average a return of 700$ per acre to the land owner while removing 10 to 15 thousand board feet per acre.