The caption of one of the photos - 'The pylon stays, the gas holder will go' - made me think: Will pylons ever go away? Is there any possible future tech out there that might make electricity pylons a thing of the past too?
It is possible to put that all underground, that's just extremely expensive. (That's currently a hotly debated topic in my region, since the new north-south connection in Germany is very controversial and underground transmission is sometimes brought up as a solution, though not really a realistic one.)
I really don't know if underground transmission will ever be economical. In principle it's possible, though, if you want to spend the money.
Not only expensive to run things underground, it introduces maintenance nightmares. Overhead lines can easily be inspected and even repaired while in service [1]. Underground lines cannot easily be inspected or repaired. Even when there are multiple lines, failures can overload the remaining lines as happened in Auckland [2]. If you want to get an idea of the hassle repairing an underground line is like, read this series of posts [3].
Not perhaps extremely expensive, but it may be more expensive than setting up pylons. But for instance when crossing waters, it is more practical to have an underwater cable than build pylons across sea.
It's no future tech - building electricity transfer and distribution underground is a perfectly standard thing to do, particularly in European cities. Where I live, even countryside 20 kV distribution lines are being dug into ground, to avoid trees falling on the wires in winter and subsequent power cuts, and to reduce maintenance cost (no need to clear trees and vegetation from around the lines).
There are some limitations; for instance, on long transfer lines underground - we're talking about 100 km here - you may need to convert to DC in between because underground cables have stronger reactive components which makes voltage control difficult.
20kV is not very much, the one in the picture is probably 275 or 400kV.
The pylon shown is the end one — the wires on the left side go down to the ground. It's probably on the edge of a city somewhere, within British cities electricity distribution is buried.
Yes, 20 kV is not much, but also 400 kV can be underground. What I meant is that even with such low voltage as 20 kV and even in countryside it may be worth it to bury the cable.
Sure, we just need decent local power generation. For example, if we can get each village or even block to have its own little nuclear plant, who needs pylons?
practical room-temp superconductors might make electricity transmission possible on smaller towers, but unless we get some cool tech like mostly autonomous underground cable tunneling robots, its likely to remain cheaper to run them on poles in most places for the forseeable future.
