What are the different strengths and weaknesses of overhead and underground service that affect performance and reliability?
While underground facilities are not as susceptible to wind and debris-blown damage, they are more susceptible to water intrusion and local flood damage, which can make repairs more time consuming and costly. Overhead facility damage is easier to locate than underground and can generally be repaired quicker. Underground interruptions may be less frequent, but typically last longer due to more complex repair requirements. Following hurricanes, we’ve found that areas that took the longest to repair were generally those served by underground facilities still flooded days after the storm passed. Damage and corrosion of underground electrical systems often shows up days or even months later, causing additional outages and inconvenience to customers. Storm winds can damage both types of systems causing outages. Overhead systems face outages resulting from trees and debris blowing into lines. Underground systems face outages from trees collapsing on above-ground transformers and switch boxes
