Ask Lemmy

AC lines would get large capacitance losses being buried vs. overhead. ElectroBOOM explains why in his vid about high-voltage DC lines starting at this point in the vid.

Granted this is at high voltages in the five-digit range and beyond, and I'm not sure how much that would matter at 240V split-phase that homes typically get in North America*, but that's a technical reason why power lines are still overhead regardless; it's more efficient and with less capacitance losses to have overhead power lines spaced far apart than to bury them.

*Yes, really, I meant what I said, North American homes still get 240V, but it's split down the middle; 120V circuits for things like lighting and such, and normal devices that you plug into a NEMA-5 outlet such as portable space heaters, use a single hot line and a neutral line while 240V circuits for high-powered appliances like clothes dryers, ovens, HVAC systems, and things of that nature, use both hot lines, and optionally neutral in addition for things in, say, an oven or a dryer that only need 120V such as lighting, while the heating elements need 240V in those applications.

My neighborhood, built from bare dirt about 30 years ago, does, as do the other neighborhoods and commercial sites built here since then.

The answer is always money, though. It's cheaper to put wires up on poles, so that's how it was done. It's expensive to move them underground, so the wires stay up on poles.

Money.

Let me reverse the question

Why do power cables need to be buried in non dense urban area?

Yes it will make it a bit ugly, but so what?. It's not like it being ugly will do anything anyway. It's not like being a bit ugly is a very annoying thing unlike when there a trash heap and it smells bad.

I think we should just keep it up there for sub-urban and rural areas, and invest the saved money on other things.

Also, im from developing country so my perspective is bit different for this topic.

One thing to be aware of is that it's much easier and cheaper to repair damages or upgrade it. Underground is not without problems too, moisture or ground movement for example.

They are safer and less prone to fault underground.

It just costs more.

it's about cost. They're more expensive to bury and to maintain.

And it's not that helpful in storms either because even if the lines near your house are burred, they're still connected to the above ground stuff that runs along roads, rural areas, and the big transmission lines themselves.

In Germany: They are in the more urban areas.
The more rural have it either on street poles, poles on the roof, both or underground.

Cost. Including maintenance costs.

You can do it, but it costs more. I understand that some of the reason that California's electricity rates are as high as they are is because PG&E is doing a bunch of burying lines.

EDIT:

https://schlanj.substack.com/p/why-electricity-prices-in-california

The IOUs spent $7.7 billion in 2024 on wildfire mitigation, which equates to 4.2 ¢/kWh. Due to years of fire suppression, exacerbated by warming trends, and the desire to build homes in wooded areas, wildfires caused by downed distribution lines are a never-ending problem. To resolve the situation, the utilities are burying the power lines, but the cost is enormous.

Wildfire mitigation accounts for just over half of the price premium.

If you think that's antiquated you should see all the aspects of our grid.

It costs less to maintain poles in high density areas than it would to burry them and have to close off entire neighborhoods.

places with above ground lines are effectively low priority for the municipality and utility companies. it's the common way in places where it's common because short term benefits are always treated as more important than long term benefits

They are in most residential areas here in Denmark.