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Buried Power Transmission Tech Update

Unread postPosted: Thu 08 Feb 2018, 16:41:39
by KaiserJeep
Utilities Bury More Transmission Lines to Prevent Storm Damage
Facing hurricanes and public opposition to overhead lines, utilities are paying extra to go underground
26 Jan 2018 | 16:00 GMT
By Peter Fairley
In the past six months, transmission lines have been destroyed by hurricanes in Puerto Rico, singed by wildfires in California, and bitterly opposed by residents in Utah and Pennsylvania who want to stop utilities from building more.

Such problems have grid operators literally thinking deeper. Increasingly, utilities in the United States and elsewhere are routing power underground. Puerto Rico’s grid rebuild is a prime example: A proposal, crafted by an industry-government consortium late last year, calls for “undergrounding” transmission to harden a power system still recovering from Hurricanes Irma and Maria.

Re: Buried Power Transmission Tech Update

Unread postPosted: Sun 11 Feb 2018, 20:29:52
by Subjectivist
I can recall when my local telephone company buried most of their lines. That was back in the 1970's after they were sued by the family of a driver who slammed into a telephone pole.

Re: Buried Power Transmission Tech Update

Unread postPosted: Sun 11 Feb 2018, 23:12:29
by Outcast_Searcher
Burying lines seems to be more common practice for newer subdivisions, especially in higher cost areas. They just apparently include the extra cost in the houses.

I noticed this in 2003 after a huge local power outage that took out power due to an ice storm to over 200,000 residents in my 320,000ish population city area. That mess lasted for weeks, and LOTS of people were without power in freezing temps for at least a week.

Various friends of mine in newer subdivisions pointed out that their power was all underground, so except for when (for example) a nearby substation was damaged, they didn't lose power. And when they did, it tended to come on in more like 12 hours than a week or more.

Since no one wants to fix the problem overall due to the cost, that's one of the reasons I am considering a solar / battery backup solution at the point the cost / convenience / availability makes sense to me. (In the mean time, my whole house generator works great - I'd just as soon not pay to replace it when it becomes unreliable at some point).

Re: Buried Power Transmission Tech Update

Unread postPosted: Mon 12 Feb 2018, 21:22:32
by KaiserJeep
In new construction, the cost penalty for underground power transmission is 1.5X-2X the cost of regular and vulnerable overhead power. The wiring although different (conductive versus convection cooling) costs about the same, you trade off the cost of the trenching against the steel towers and wooden power poles. The higher cost figures you hear are for burying existing overhead power in an area that is already built up.

In Puerto Rico, we are actually looking at costs somewhere between the low/high figures. Many existing structures and roads were destroyed, the very high costs only apply in cities, where prolonged outages were simply not experienced. The vulnerability to long term outages - such as the 5+ months that some rural PR areas have been without power - are in the hinterlands, where at least the major transmission lines should be buried to prevent the recurrence of lengthy outages.