Why Do High-Voltage Transmission Lines Have No Insulation Coating?

High-voltage transmission lines are designed with thick conductors that carry enormous amounts of electrical energy across long distances. However, unlike the insulated wires we see in household electrical systems, these power lines are exposed without any insulation coating. This often raises the question: why are these high-voltage lines left bare? The reason lies not only in cost considerations but also in engineering principles and safety requirements. In this post, we will explore the scientific and technical reasons why high-voltage transmission lines are designed without insulation coating.     Air as a Natural Insulator The primary reason high-voltage transmission lines are not insulated is that air itself is an excellent insulator . Electricity requires a potential difference to flow, but air can withstand hundreds of thousands of volts without allowing current to pass through. For example, a 1-meter air gap can insulate more than 300kV. Transmission...