The differences between overhead and underground power lines
September 26, 2016
There are two methods of installing the power lines that carry electricity to your home, overhead and underground. South Central Power members sometimes ask why we use one versus the other, or more to the point, why all power lines are not installed using the underground construction method. Isn’t one method better than the other? These are great questions, and the answer is that each method has its place.
Overhead line construction starts with the setting of utility poles. Poles can be set in nearly any type of terrain, even rocky. In the case of heavy rock, special equipment is used to augur out the hole. If placement occurs in boggy or wet terrain, many techniques are available to set poles securely. Once the poles are in place, wires can be strung and then equipment––like transformers, fuses and reclosers––are installed. Power can now flow.
Underground line construction requires digging a trench that is deep enough to keep the lines well away from surface activities. Where the terrain is extremely rocky, underground lines may not be an option. Next, wires are laid in the trench directly or placed in conduits for protection. The trench is filled in, and the surface is restored to its original condition. Padmount transformers and additional equipment are installed as needed, now the system is ready to deliver electricity.
Determining if power lines should be overhead or underground boils down to what is best for the situation. Underground lines might be ideal in situations where there is a desire to keep the poles and wires out of sight, such as a residential neighborhood, park or historical area. There are many cities and towns that construct only underground lines for a variety of reasons.
Overhead systems work well when appearance is not a major concern. Examples include extremely long line distances across country, where the voltages are higher than the limitations set for underground lines.
The ultimate mix of underground and overhead construction used by South Central Power provides you, our members, with the highest possible quality of service at the lowest possible price. Cost, appearance, reliability, maintenance and future upgrades will drive which is the better approach, overhead or underground.