ST. PETERSBURG, Fla. (WTSP) – With widespread power outages across Florida in the days following Hurricane Irma prompting what some called the largest electrical restoration effort in U.S. history, many people are asking: Why continue to put power lines above ground instead of underground?

The easy answer: money. But as is the case with most complicated issues, the easy answer fails to tell the entire story.

Yes, overhead power lines are cheaper to install, repair and rebuild than underground power lines. But power utility companies are required by the Florida Public Service Commission to provide electricity in the most cost-effective manner -- which, in most cases, is in the form of overhead power lines.

A 2012 study found that putting power lines underground can cost five-to-10 times what it costs to hang them from power poles.

Tampa Electric customers can request that power lines to their homes be moved underground, the cost of which is assessed to the customer. But underground lines are not storm-proof.

“Underground lines are a little more reliable than overhead lines but not significantly so. The downside is an outage on an underground line takes longer to find and longer to fix because of the difficulty accessing them,” said Tampa Electric spokesperson Cherie Jacobs. “The overhead lines are susceptible to damage from wind and wind-borne debris. Underground lines are susceptible to flooding and saltwater intrusion.”

Jacobs says about 40 percent of TECO’s power lines are currently underground, most of those in newly constructed neighborhoods.

She says the company has spent almost $480 million in strengthening its infrastructure over the last 10 years installing things like concrete and steel transmission poles. Similarly, Duke Energy has spent $2.4 billion since 2004 strengthening its system and Florida Power & Light says it has spent $3 billion in upgrades since Hurricane Wilma in 2005.

“We have the strongest, most highly engineered, smartest grid in the U.S., but there is no way to engineer against a storm of this kind of magnitude,” Silagy told Bloomberg in the days before Irma came ashore in Florida. “Even underground facilities are going to be subject to outages because of flooding and storm surge.”

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