Recent trends in distribution line undergrounding.
William Atkinson is a freelancer who writes occasionally for Public Utilities Fortnightly. Contact him at w.atkinson@mchsi.com.
Following a large storm causing a lengthy power outage, one can bet that media coverage will turn to at some point to underground lines. Future outages will be averted, presumably, without overhead lines exposed to falling tree limbs. And children will play safer absent the danger of contact with live wires, exposed above ground.
But just as there are pros and cons to overhead distribution lines, the same can be said for undergrounding, starting with cost.
"Building overhead lines is very cost-effective," said Frank Alonso, P.E., manager, transmission line engineering, for Leidos Engineering (Orlando, Fla.), who also has experience with distribution lines.
"The material is less expensive, the insulation requirements are significantly less, and the maintenance is relatively inexpensive compared to underground," he said. Another benefit is that, when an outage occurs, it can almost always be located quickly. "Overhead lines are also very easy to tap into," he said.
Yet overhead lines can prove vulnerable even in good weather.