After a snowstorm late last month knocked out power to nearly 700,000 Massachusetts residents, Gov. Deval Patrick and Richard K. Sullivan Jr., the secretary of Office of Energy and Environmental Affairs, said burying the state's power lines could help prevent future outages, according to media reports, but the massive undertaking would cost a jaw-dropping $1 trillion.
The figure came from Thomas May, the CEO of NStar, during a post-storm meeting, according to a spokeswoman for Sullivan.
Caroline Allen, an NStar spokeswoman, said the figure was "not a formal estimate." She said the figure was meant to "demonstrate the complexity involved in building an underground system."
"There are so many variables ... a more accurate estimate can't be discussed without a complete engineering review of the entire state," she said. "Tom was pointing out that it would be astronomically expensive."
Undergrounding all power lines would be an expensive, multidecade effort. The cost per customer would almost surely make the project uneconomical. And underground power lines are not immune to outages.
The Edison Electric Institute (where May is a board member), which represents shareholder-owned electric companies across the country, concluded in a 2009 study that conversion costs for distribution lines could range from $80,000 per mile in rural areas to $2.1 million in urban areas. For transmission lines it would be even more.
The state has about 29,080 miles of distribution lines and approximately 1,700 miles of overhead transmission lines. Using the high end of the EEI price estimates, it would cost Massachusetts about $99.1 billion to bury all power lines, more than 10 times less than a trillion dollars.