Overhead vs. Underground Power Lines

October 26, 2021

Why aren’t all power lines underground?
Storms often stir up questions about overhead versus underground distribution of electricity. For example, when powerful winds roll through our area, like summer storms or hurricanes, and we experience widespread outages, we are often asked why aren’t all of our power lines buried underground—and if a line is underground—why does the power still go out.

The answer is quite simple. While more than half of the Cooperative’s lines are underground, overhead lines are still more affordable to construct, repair, and maintain, which helps keep costs affordable for our members. In addition, our crews can visually inspect faults on the line, and repairs are usually made quicker. Those factors play a prominent role when severe storms and hurricanes strike our area, and our crews need to find and fix problems safely and quickly.

That’s not the case with underground lines. While the Cooperative uses the most reliable underground technologies and materials available, such as insulated cable and protective conduit, problems with existing underground cables can still take longer to find and fix. Additionally, installing underground cables costs significantly more than building overhead lines, and they are much more expensive if they need to be replaced.

“When the power goes out, there are two obstacles our crews face before they can fix a line,” said David Medlock, line superintendent at Union Power. “One is identification of the fault, and then two is having access to the line in order to make the necessary repairs. While smart grid technology—devices that tell us exactly where in the system a given disruption lies—makes identifying faults easier, access to underground systems is hindered. Repairs often require disruptive digging and are intensified by severe weather conditions.”

Another factor worth mentioning is that many of the outages we currently receive on our underground system are due to other utilities digging into our underground cables. And as more utilities like telephone, gas, and cable companies are putting more of their services underground in the same area, it makes our lines more likely to get hit.

Home improvement projects that involve digging also play a significant role. That’s why it is vital to call 811 before starting any digging projects to ensure all underground power lines are avoided. It’s a free service that gives Union Power and other utilities time to locate and mark our cables properly and helps keep you safe and the power on.

Rest assured, whether lines are overhead or underground, we are always prepared to respond in the event of an outage. As your electric cooperative, Union Power is dedicated to delivering safe, reliable, and affordable energy to our members daily and during the more difficult times.