The US electrical system

[richard.cs]

Underground wiring is far more expensive to install and maintain than overhead. While it's true that it isn't as prone to damage in wind storms that knock trees down it's not immune, a root ball from a fallen tree can really do a number on underground wires. It's also far more prone to damage from flooding and tremendously more difficult to troubleshoot and repair. It works well in areas that are dry and have relatively few trees though.

I am with you on more expensive to install but unconvinced on underground cable maintenance being more expensive than overhead, at least in a UK-like climate. Sure it costs more to actually do the repair but it is rare. Here underground cable faults are more often from people digging them up by accident* than by tree roots and similar though it does happen. Failures not caused by digger buckets are often poorly installed joints or places where the cable sheath was nicked on installation leading to eventual to water ingress. I don't see why the cables themselves would be considered vulnerable to flooding? They're waterproof and often installed below the water table anyway. A majority of all the underground cables ever installed in the UK are still in service, thousands of miles of 1950s lead-covered cable still in-use. In comparison we loose lots of overhead cables every time there's a storm and routine maintenance is needed too - regular tree cutting, replacement of the poles every 30 years or so, etc.

Generally I expect our electricity suppliers to do the cheapest thing, and they seem to have settled on putting new cables underground by default in urban and suburban areas. This may be influenced by them being fined for customer minutes off supply, so powercuts have a significant financial cost.

*Yes someone pays to fix these (and other expenses incurred as a result), but it's not the cable owner.

[TimFox]

Yes, everything in engineering involves a trade-off between installation cost and operating cost.  It depends on how much it costs to repair ice-storm damage, and often it occurs, and if the power company is liable for consequent damage.  New York City banned overhead wires sometime after a serious blizzard in 1888, although there are still some areas in the city (annexed thereafter) with overhead wires.

[themadhippy]

It's also far more prone to damage from flooding and tremendously more difficult to troubleshoot and repair. It works well in areas that are dry

meanwhile in the uk we run 400KV cables under the towpath and use the canal water to keep the cables cool

[IanB]

Generally I expect our electricity suppliers to do the cheapest thing, and they seem to have settled on putting new cables underground by default in urban and suburban areas.

In the UK I would think this is more about planning consent than cost. When there is a new development every detail has to be negotiated with the planning authority, and I would assume that "all cables are underground" is high on the list of requirements.

Weirdly, not long ago the National Grid were upgrading a substation near where I grew up (I used to fall asleep every night to the transformer hum floating miles across the countryside--but I digress), so anyway they were upgrading the substation and they actually did a public consultation about the design of a new switch yard--air insulated circuit interrupters or gas insulated interrupters. The air breakers were bigger, required more land area, but were cheaper and easier to maintain, while the SF6 breakers were more compact and had a smaller footprint, but were more expensive. People voted for the SF6 design, and they accepted the result of the poll. I was surprised they actually did that consultation exercise.

[james_s]

It's also far more prone to damage from flooding and tremendously more difficult to troubleshoot and repair. It works well in areas that are dry

meanwhile in the uk we run 400KV cables under the towpath and use the canal water to keep the cables cool

How many junctions, switches, fuses, and transformer vaults are down there under the canal water? How much does it cost to maintain them? Do you think the UK possesses some magical technology that North America lacks? Keep in mind the entire country is smaller than some of our individual states, there has got to be a lot less electrical infrastructure, vastly fewer km of cable.

This is one source I came across: "According to the May 2011 paper “Underground Electric Transmission Lines” published by the Public Service Commission of Wisconsin, “The estimated cost for constructing underground transmission lines ranges from 4 to 14 times more expensive than overhead lines of the same voltage and same distance."

Underground lines have their place, they have advantages, but they also have disadvantages. Because of that we typically use underground in cities and modern suburbs but the long runs between towns are usually overhead.

[richard.cs]

meanwhile in the uk we run 400KV cables under the towpath and use the canal water to keep the cables cool

How many junctions, switches, fuses, and transformer vaults are down there under the canal water? How much does it cost to maintain them? Do you think the UK possesses some magical technology that North America lacks? Keep in mind the entire country is smaller than some of our individual states, there has got to be a lot less electrical infrastructure, vastly fewer km of cable.

This is one source I came across: "According to the May 2011 paper “Underground Electric Transmission Lines” published by the Public Service Commission of Wisconsin, “The estimated cost for constructing underground transmission lines ranges from 4 to 14 times more expensive than overhead lines of the same voltage and same distance."

Here we make a distinction between "transmission" at >100 kV, "HV distribution" generally at 11 kV and 33 kV, and "LV distribution" at 400 V (all line to line).

The vast majority of our transmission network is overhead - at these voltage levels underground becomes very expensive, but in urban areas both HV and LV distribution tends to be underground, and there is very little suburban HV distribution.

Underground lines have their place, they have advantages, but they also have disadvantages. Because of that we typically use underground in cities and modern suburbs but the long runs between towns are usually overhead.

Well yes, we tend to do that too, noting that "long runs" are always at higher voltages. The point I was making is that this kind of thing: https://goo.gl/maps/rqwRZZQkqCgEUxqQ6 with HV distribution on poles in a urban area just does not exist here at all.

[tom66]

There are some 275kV cables that run under an office estate I used to work at in Leeds.  I'm not sure why they ended up there but I recall National Grid was pissed that someone had built an estate over this underground line.  They had assumed they would always be able to dig to access the cable!

[themadhippy]

How many junctions, switches, fuses, and transformer vaults are down there under the canal water?

none ,but then again no mention of those factors was mentioned by the claim

It's also far more prone to damage from flooding

The added advantage is no road closures if a fault does occur,and the heat from the cables keep the tow path frost free

with HV distribution on poles in a urban area just does not exist here at all

https://goo.gl/maps/zkvizUUCEwnNckxJ8

[Monkeh]

with HV distribution on poles in a urban area just does not exist here at all

https://goo.gl/maps/zkvizUUCEwnNckxJ8

Well, they're not poles..

[james_s]

The added advantage is no road closures if a fault does occur,and the heat from the cables keep the tow path frost free

I don't see how they avoid road closures if there's a fault, here they typically have to close at least a lane to excavate a faulty underground cable, sometimes it's quite a major project. There have been a few cases where underground transformer vaults have caught fire or exploded and left a crater in the street. If it's an overhead line the fault is usually a large tree falling across the line (and the road) so the road is closed while crews clear the tree, repairing the power lines doesn't normally require any sort of closure, they just park the utility truck on the shoulder and get to work. It doesn't really happen very often though, just when a big storm rolls through at which point there are often road closures all over from downed trees, most of which don't involve power lines.

Somebody posted this a few days ago https://www.youtube.com/channel/UCpJWHeFjOjoDrHLIPqIHgwA
He's based in Canada but their system is pretty much the same as what we use here in the US. Older and rural areas are typically exclusively overhead, newer, urban and/or more upper class areas that can afford the cost are usually underground.

[themadhippy]

I don't see how they avoid road closures if there's a fault

here in the uk its  rare to find vehicles on canal towpaths,maybe its different in america

[IanB]

here in the uk its  rare to find vehicles on canal towpaths,maybe its different in america

Speaking of which, I wonder how they get motorized vehicle access to maintain their poles? Or for that matter the transmission tower visible on the other side of the canal? In California transmission and distribution lines tend to be placed along a vehicular right of way. In the UK they seem to get plonked down anywhere across the countryside.

The pole in the foreground appears to be burnt. Lightning strike perhaps?

https://goo.gl/maps/MhbJjs7dMU1i61JF9

[themadhippy]

Lightning strike perhaps

more likely local scrotes trying to set them on fire

[AlbertL]

with HV distribution on poles in a urban area just does not exist here at all

https://goo.gl/maps/zkvizUUCEwnNckxJ8

Well, they're not poles..

Love the towers in the middle of the roundabouts!  That must have taken some serious coordination between the utility and the road authority.

[Monkeh]

with HV distribution on poles in a urban area just does not exist here at all

https://goo.gl/maps/zkvizUUCEwnNckxJ8

Well, they're not poles..

Love the towers in the middle of the roundabouts!  That must have taken some serious coordination between the utility and the road authority.

I think it's far more likely they built that entire estate around them to save costs. They're actually gone now anyway. At least 8 years gone.

[themadhippy]

They're actually gone now anyway. At least 8 years gone.

Have they? Another childhood memory gone.

[richard.cs]

with HV distribution on poles in a urban area just does not exist here at all

https://goo.gl/maps/zkvizUUCEwnNckxJ8

Well, they're not poles..

This is the transmission vs distribution distinction I was trying to make. We have >100 kV lines on towers passing through some urban areas because at those voltages underground just gets crazy expensive, but the general power distribution for that area, at moderate HV voltages of 11-33 kV (we used to call this "medium voltage" / "MV") is underground. Scrolling way back we were discussing shared HV and LV on poles, etc. and this is something we never get on those kind of towers.

Also it's not a pole

Speaking of which, I wonder how they get motorized vehicle access to maintain their poles? Or for that matter the transmission tower visible on the other side of the canal? In California transmission and distribution lines tend to be placed along a vehicular right of way. In the UK they seem to get plonked down anywhere across the countryside.

In this case probably either by driving carefully along the towpath which might just have enough gap between poles and water, or by boat. A lot of distribution poles here are across farmland and and accessed with offroad vehicles.

The pole in the foreground appears to be burnt. Lightning strike perhaps?

https://goo.gl/maps/MhbJjs7dMU1i61JF9

This is 33 kV distribution, and I think the black areas on the pole are just places where the wood preservative is darker.