7 ms·

So bury all the cables/equipment underground? I'm sure costs are substantially higher to do so, but we could add other infrastructure along these underground li

So bury all the cables/equipment underground? I'm sure costs are substantially higher to do so, but we could add other infrastructure along these underground lines as well if there was a shred of political will to accomplish this.

VLM 8y ago
From a safety engineering standpoint it would be much cheaper and safer not to live in a tinderbox than to try to make a tinderbox fireproof. It seems a bad investment to try to live there.
- dsfyu404ed 8y ago
  In a fight between logic and "surf and ski in the same day, brah" logic is not what wins.
  - sgc 8y ago
    That is a useless comment. People should not live in hurricane areas, in tornado alleys, etc. But they do. So the infrastructure needs to be designed for it. What people's pastimes are is totally irrelevant and obviously does not inform this type of decision a whit.
    - dsfyu404ed 8y ago
      That's not my point. My point is that people don't take long term risk of mother nature screwing them into account when they're deciding where to live, they just look at the short term benefits. They don't bother to account for there being a high chance of mother nature destroying their home within their lifetime. "Surf and ski in the same day brah" is an example of a short term benefit.
smolder 8y ago
Or just surround electrical equipment with good old nonflammable concrete.
Mvandenbergh 8y ago
So typically burying a cable at HV or EHV is an order of magnitude more expensive than overheads. Underground cables are also prone to thermal issues (ironically) so I don't know that you'd be reducing fire risk as much as you'd think. Much of the ignition risk comes from transformer explosions, air-insulated CB arcs, and line-to-tree arcs. Transformer explosions are inherently harder to isolate from flammable material in the American distribution system design than they would be in a European 240v system, that's because the US system has to keep LV (110v) runs short so has extensive HV networks with pole-mounted transformers feeding a small number of properties each. 240v systems can tolerate longer LV runs and use larger pad-mounted distribution transformers with about 20x the power rating of American style pole-mount transformers. In the Euro configuration, you therefore have many fewer transformers which have a least a fence around them with regular vegetation control within it. You can also put these transformers within enclosures. A typical UK rural/suburban arrangement has the transformer air cooled and outside within a fence with breakers and distribution boards inside a brick or GRP hut inside the fence. In urban areas the whole thing is enclosed in its own structure or in the basement of a building. Anyway you can't do that with American transformers as there are more of them. These will therefore always be an ignition risk. Yes you can step up planned replacement of older models, be more aggressive about keeping the load per transformer down to lengthen lifetime and reduce fault risk but fundamentally they are a risk. You can replace air insulated CBs with gas-insulated models at significant expense, that will reduce that risk. Burying cables as I said is horrifically expensive but you could increase the size of the vegetation-cleared right of way around the overheads and step up the clearance schedule. None of these will remove every source of ignition.
- crunchlibrarian 8y ago
  Super informative, thanks
- sgc 8y ago
  There are certain areas which are known to be very high risk with population centers in the expected path of travel of a fire. It is criminally negligent to not bury lines or provide other extremely robust fire risk reduction measures in these areas. Although not exclusively, the conversation needs to focus on the smaller areas of highest risk.
pdkl95 8y ago
PG&E apparently[1] has a project to improve the infrastructure in some areas. They are replacing the existing 12kVA lines with insulated 15kVA lines that still carry 12kVA service. This should provide a larger margin for transient problems and protect against some types of arcing. They are also retrofitting some poles so they hold the individual cables farther apart. However, the real problem is trees/etc growing too close to the lines, compounded by the extra dry drought conditions throughout CA. Regardless of the type of cable or other technical safety features, power lines are always going to be a fire hazard if they don't receive regular inspection and maintenance. The lesson from these fires is that the existing maintenance schedule is severely inadequate. [1] https://www.youtube.com/watch?v=L2nWuZ8J0Go https://www.youtube.com/watch?v=L2nWuZ8J0Go
planteen 8y ago
I've wondered why it wasn't underground as well. I live in Colorado and have underground at my house. The EIA says underground is 5-10x more expensive. https://www.eia.gov/todayinenergy/detail.php?id=7250 https://www.eia.gov/todayinenergy/detail.php?id=7250

VLM 8y ago

From a safety engineering standpoint it would be much cheaper and safer not to live in a tinderbox than to try to make a tinderbox fireproof. It seems a bad investment to try to live there.

dsfyu404ed 8y ago
In a fight between logic and "surf and ski in the same day, brah" logic is not what wins.
- sgc 8y ago
  That is a useless comment. People should not live in hurricane areas, in tornado alleys, etc. But they do. So the infrastructure needs to be designed for it. What people's pastimes are is totally irrelevant and obviously does not inform this type of decision a whit.
  - dsfyu404ed 8y ago
    That's not my point. My point is that people don't take long term risk of mother nature screwing them into account when they're deciding where to live, they just look at the short term benefits. They don't bother to account for there being a high chance of mother nature destroying their home within their lifetime. "Surf and ski in the same day brah" is an example of a short term benefit.

smolder 8y ago

Or just surround electrical equipment with good old nonflammable concrete.

Mvandenbergh 8y ago

So typically burying a cable at HV or EHV is an order of magnitude more expensive than overheads. Underground cables are also prone to thermal issues (ironically) so I don't know that you'd be reducing fire risk as much as you'd think. Much of the ignition risk comes from transformer explosions, air-insulated CB arcs, and line-to-tree arcs. Transformer explosions are inherently harder to isolate from flammable material in the American distribution system design than they would be in a European 240v system, that's because the US system has to keep LV (110v) runs short so has extensive HV networks with pole-mounted transformers feeding a small number of properties each. 240v systems can tolerate longer LV runs and use larger pad-mounted distribution transformers with about 20x the power rating of American style pole-mount transformers. In the Euro configuration, you therefore have many fewer transformers which have a least a fence around them with regular vegetation control within it. You can also put these transformers within enclosures. A typical UK rural/suburban arrangement has the transformer air cooled and outside within a fence with breakers and distribution boards inside a brick or GRP hut inside the fence. In urban areas the whole thing is enclosed in its own structure or in the basement of a building. Anyway you can't do that with American transformers as there are more of them. These will therefore always be an ignition risk. Yes you can step up planned replacement of older models, be more aggressive about keeping the load per transformer down to lengthen lifetime and reduce fault risk but fundamentally they are a risk. You can replace air insulated CBs with gas-insulated models at significant expense, that will reduce that risk. Burying cables as I said is horrifically expensive but you could increase the size of the vegetation-cleared right of way around the overheads and step up the clearance schedule. None of these will remove every source of ignition.

crunchlibrarian 8y ago
Super informative, thanks
sgc 8y ago
There are certain areas which are known to be very high risk with population centers in the expected path of travel of a fire. It is criminally negligent to not bury lines or provide other extremely robust fire risk reduction measures in these areas. Although not exclusively, the conversation needs to focus on the smaller areas of highest risk.

pdkl95 8y ago

PG&E apparently[1] has a project to improve the infrastructure in some areas. They are replacing the existing 12kVA lines with insulated 15kVA lines that still carry 12kVA service. This should provide a larger margin for transient problems and protect against some types of arcing. They are also retrofitting some poles so they hold the individual cables farther apart. However, the real problem is trees/etc growing too close to the lines, compounded by the extra dry drought conditions throughout CA. Regardless of the type of cable or other technical safety features, power lines are always going to be a fire hazard if they don't receive regular inspection and maintenance. The lesson from these fires is that the existing maintenance schedule is severely inadequate. [1] https://www.youtube.com/watch?v=L2nWuZ8J0Go https://www.youtube.com/watch?v=L2nWuZ8J0Go

planteen 8y ago

I've wondered why it wasn't underground as well. I live in Colorado and have underground at my house. The EIA says underground is 5-10x more expensive. https://www.eia.gov/todayinenergy/detail.php?id=7250 https://www.eia.gov/todayinenergy/detail.php?id=7250