Jul 27 - McClatchy-Tribune Regional News - The Arizona Daily Star, Tucson


With monsoon wind gusts twisting power lines, at times to their breaking point, one Star reader asked last week in a letter to the editor why local electric companies don't just bury the lines.

The main reason Tucson Electric Power Co. doesn't go with underground power lines is the benefits don't outweigh the costs, said TEP spokesman Joe Salkowski.

"This is not to say underground lines would not be advantageous in a storm," Salkowski said.

TEP has 2,631 miles of line in its distribution area. In 2006, Edison Electric Institute estimated the cost of burying power lines at $1 million per mile, which Salkowski said is consistent with TEP's estimates.

That puts the price tag for burying TEP's line at $2.63 billion -- or $6,660 per customer -- Salkowski said.

Also, while underground lines are less vulnerable to storm damage, they can get hot during the summer months as demand for power increases, Salkowski said. And hot lines can also lead to failures, he said.

If underground lines do fail, it can take longer to locate the damage, so while there might be fewer outages, those hiccups in power tend to last longer, Salkowski said.

Plus even if TEP did put its lines underground there would still be 800 miles of transmission and subtransmission lines that would remain vulnerable to storms, he said.

(c) 2009, McClatchy-Tribune Information Services