Will insulation on electric power lines affect the flow of power?

[KurtLudwig]

TL;DR Summary

Will insulation of electric power lines interfere with delivery of electric power? It would greatly decrease the setting of fires in dry conditions.

If electric power lines were insulated, there will be no or much less sparking between wires when poles are blown down during high winds.
(I am thinking of the recent fire in Lahaina, Maui. My granddaughter barely escaped the fire. The family lost all their homes.)
I had believed that electricity was conducted inside of copper wires. Then I read that the energy is carried by the electromagnetic field, mainly outside of the copper wires. How does insulation affect the electric field around a current-carrying wire? Will it impede the flow of electric energy?
I have also read on Wikipedia about a Poynting vector inside a co-axial cable. I am not sure I fully understand the concept of vectors. Could you elaborate?

 

[Dale]

TL;DR Summary: Will insulation of electric power lines interfere with delivery of electric power? It would greatly decrease the setting of fires in dry conditions.

My granddaughter barely escaped the fire. The family lost all their homes.

I am glad they escaped with their lives and sad to hear they lost their home.

How does insulation affect the electric field around a current-carrying wire? Will it impede the flow of electric energy?

Insulation would not impede the flow of electrical energy along the wires. It would add to the cost, both of the wire itself and also the supports needed to hold the extra weight.

 

[Baluncore]

Insulation is a disadvantage.
1. Insulated wire costs more than bare wire.
2. It weighs more, so needs thicker wire, and poles to support it.
3. It has greater wind section, so needs better support wires and poles.
4. The melting point of insulation limits the wire temperature, so wire must be thicker, which then needs a greater circumference of insulation.
5. In winter, it insulates, so prevents melting ice on the lines with reactive current.

A fallen insulated line will have a bare end without insulation. That will start surface fires.

Insulation is really only needed where trees can contact the power lines. Trimming trees will reduce the fire problem significantly.

If you insulate the wire, you might as well place it underground in a conduit.

 

[KurtLudwig]

Thank you for your answers.

 

[russ_watters]

Thank you for your answers.

Wait - before you go, another common/related question is why we don't bury power lines underground:
https://www.starenergypartners.com/blog/electricity-company/why-dont-we-bury-power-lines-underground

But that's the power company's answer. But Europe does it, so why can't we...?

 

[Baluncore]

Undergrounding power is economic in new high-density suburbs, where the earthworks are planned with drainage, before the construction of roads.

Above-ground power, indirectly, reduces the height of trees in avenues. Trees block the sun and wind, which reduces temperature extremes. Tall trees cast longer shadows, over more PV panels. Tall trees drop limbs, or fall on houses during windstorms, or burn during bushfires.

My state-owned power-company inspector told me to replace my two privately-owned timber power poles, because they had signs of rot. They quoted AU$2k each at the time.
I have a vintage JCB backhoe for gardening, so I buried a 3PH line in conduit, from the road to my house. I now buy power at the front boundary. The power company had to finance and install a pole to cross the public road for my connection. At the same time, I converted from 1PH to 3PH, so they were required to upgrade their transformer, at their cost. I had to apply to Municipal Council for an easement, to cross the 1 foot (300 mm), underground from the State's pole to my boundary.
By going underground, I saved AU$1k and got 3PH power, (which would have required taller and more expensive power poles). I also escaped from the liability of rotting poles and overhead wires on my property.
Above all, I saved them the cost of doing the regular safety inspection of two private power poles.