The vast majority of power lines in France are overhead.

RTE overhead lines: 100000 km

RTE underground lines: 5400 km

https://www.rte-france.com/fr/document/statistiques-reseaux-...

If you are intending to distinguish between distribution and transmission, the lines in question in California are transmission lines, not distribution lines.

Wouldn't that cost something like $1 trillion to do for the entire state?

Math: 155147 miles * $750/foot

And an article https://www.desertsun.com/story/news/environment/2019/10/11/... confirming it's pretty much out of reach. $15,000 per household estimate (and 1,000 years!!).

You wouldn't necessarily have to do the entire state but rather start doing this in high-risk places first.

Good point. Is it also true that high risk places (forest/rural) are probably cheaper and easier to install underground than low risk places (urban)?

A lot of long-distance, high-voltage transmission crosses what's effectively wilderness. You've got issues of unstable slopes, earthquake faults, flooding, and ground-current losses (a big problem with undergrounded power).

And that's before you look at getting crews in place.

Then there's the question of monitoring, servicing, and repair after undergrounding.

It's definitely an option. But not a cheap or universally applicable one.

Not sure about that. The high risk places are also often in remote, rugged terrain. What you save by not having to disrupt other infrastructure you might end up spending just to get people and equipment to where they need to be. Interesting perspective here: https://www.wsj.com/graphics/california-wildfire-pge-drought...

Well then everyone has local solar with a powerwall for when PG&E shuts down. Maybe that's cheaper? Honestly I think PG&E could bury the lines cheaper than $750 a foot.

Maybe, but I think CEQA will pretty much guarantee that it will end up being a bit more expensive than even that.

Maybe ultra sparse settlements on a scale as today are unaffordable in the long run? It not just power but also the roads and communication links. Accounting for infrastructure maintenance is not done properly.

> $750/foot

2-3 times more than per square foot price of building a luxury house in California, that number totally checks out!

Well the obvious thing to do is to bury the ones in wind problem/fire risk areas

Underground power distribution doesn't last as long as above ground. So not only is it more expensive to install, you have to reinstall it more often, plus spend more money on repairs more often. Repairs take longer as well because you have to dig up the lines to do it.

Not needed really. We have last mile underground, but major distribution lines are over air. However all plants higher than few inches are cut down under the lines the width of the cut depending on how high the cables are. I can imagine it wouldn't work that well in the mountains. Here it is just a matter of regularily mowing the whole thing (few times per year).

France does everything right (but it also does everything wrong.)