Burial Benefits

I was recently featured on the Energy Cast podcast, see below:

I’ve always been a big fan of burying transmission lines—those high voltage lines hung from gigantic towers crisscrossing the countryside. During my time as a transmission project manager, we’d sometimes get budget surpluses, and I’d inevitably pitch burying a stretch of transmission lines with management. It makes sense. Burying lines increase resiliency, lower O&M, and require about the same engineering and construction as overhead.

Mike Beehler, spokesman for the Power Delivery Intelligence Initiative, or PDI2, advocates for more strategic line burials around the country. Mike says many utilities are seeing benefits of burial beyond aesthetics.

He points to the recent announcement by California-based utility PG&E to bury as much as 10% of their transmission and distribution lines, at an estimated cost of $15-30 billion. Mike says wildfires allegedly sparked by power lines nearly bankrupted the company.

“Why would [PG&E] come back, rebuild, and do the exact same thing over again?” asks Mike. “[Their CEO] said, ‘We can’t afford not to underground some of these lines.’”

Mike says California is not alone in Mother Nature’s effect on power lines. Some parts of New Orleans, hit by Hurricane Ida in 2021, endured as much as three weeks without power when the storm blew down all eight major transmission lines feeding the city. So far no plans have been introduced to bury any of those lines.

“You lost all your transmission feeds to New Orleans 2005 with Hurricane Katrina,” says Mike. “You went back and essentially built the same overhead system and then 16 years later you’re right back.”

One of the main hurdles to wider undergrounding is expense. Anecdotally, I’d been told burying lines costs 3-5X as much as overhead.

“What we’re trying to say is, no more rules of thumb,” says Mike. He argues that new technologies, materials, and economies of scale, combined with less O&M (i.e. regular tree trimming and vegetation management in rights-of-way) can lead to a “total cost of ownership” less than overhead lines.

“When they realize the amount of underground that’s going to go in is going to grow exponentially, they’re going to develop new devices to build it better, faster, cheaper,” he says.