Transmission vs. Distribution

Transmission and distribution lines are vital to the electric grid. Simply put, these power lines incorporate different voltages of power as it is transmitted from generating stations to substations and ultimately to customers.

Transmission

Transmission lines can be compared to interstate highways as they carry electricity across great distances from generating stations to primary substations. Transmission lines are installed on large structures, and the company’s transmission system consists of 69,000 volt through 500,000 volt lines and moves power from power generation plants to substations.

Trees must grow far enough from the conductors that they won’t hurt or harm individuals or cause a disruption to electric service. 

An outage on a transmission line could affect thousands of people. For this reason, trees or branches must remain far enough away that they never make contact with wires.

Distribution

Distribution lines and equipment carry electricity from local substations to customers’ homes and businesses. These lines are often found overhead on utility poles but are sometimes located underground. The most common voltage for electricity being moved along distribution lines is 12,470 volts.

LG&E and KU maintain hundreds of miles of overhead distribution power lines. Trees can pose a serious safety hazard and reliability threat to these lines if they are not maintained. Overhead distribution lines are the ones that most often experience outages related to trees and other vegetation.

For underground electric service, we need to keep as much open space as possible around the pad-mounted transformers that deliver electricity to the home or business. The pad-mounted transformer is the rectangular green box located near a property line. In order to provide easy access for LG&E and KU to get inside the transformer to perform any necessary repairs or maintenance, we advise you to keep the area free from obstructions, and to provide adequate access, work and safety clearances.

Get to know your power lines

To get power to homes and businesses, we rely on two main types of power line structures:

chart of transmission and distribution pole types

Transmission structures are typically taller, and the wires and hardware are larger in size.
Distribution poles are often shorter and may have a bucket-shaped transformer affixed to them.