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Shouldn't we be using some of the billions that will be forthcoming from the feds for infrastructure to create a fully resilient grid by putting the vast majority of it underground ?

Larry Eisenberg's picture
Principal Beezley Energy Advisors

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I originally shared this as a comment on a post on Energy Central, but thought it was worth sharing as a Q&A to generate some more discussion.

In watching the discussion about the future of the grid, a fundamental question crossed my mind.  Shouldn't we be using some of the billions that will be forthcoming from the feds for infrastructure to create a fully resilient grid by putting the vast majority of it underground ? With climate change already creating unrecognizable weather patterns, with fire season now a year-round phenomenon, and active terrorism from multiple state actors and home bred types, an underground highly secure grid with both long distance high tension lines and last mile lines all uniformly placed into high security weather proof / vandal proof / fire proof tunnels would make a lot of sense.  The history of the grid development is about how to do it in the cheapest way possible.  Yes, proper under grounding would cost a huge amount of money.  It would also create a huge amount of very well paying jobs.  The technology to do this is readily available. It would also create long term savings when we do not have to replace power lines due to fire and weather events.  Not to mention the aesthetic value of an urban and rural landscape free of the blight of power lines. Had we made this decision a long time ago, the billions devoted to rebuilding power lines after they have burned downed or been trashed by the latest tornado and/or hurricane would have gotten us a long way toward the goal of a resilient modern and stable grid that can support whatever the future of energy generation is. 

Look forward to other's thoughts on the issue.

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In Florida, my understanding is there are concerns about saltwater intrusion for undergrounding in coastal areas. The cost is also a big issue in conversions from overhead to underground, but not for new subdivisions.

Bob Meinetz's picture
Bob Meinetz on Jul 3, 2021

IMO those concerns are well-founded, Cindy.

Though the cause of the collapse of Champlain Towers South in Surfside is still under investigation, it's likely differential subsidence, or the uneven settling of ground underneath massive seaside buildings weighing 4,000 tons or more, played a role:

"The Miami-area apartment building that crashed to the ground in a horrifying early-morning collapse Thursday had been experiencing 'issues' for years, and it was even the subject of a scientific study last year that warned of it sinking into the earth.

"The Champlain Towers complex in Surfside, Florida, was the subject of at least one lawsuit over the maintenance of the structure’s outer walls. In addition, the building attracted the attention of scientists alarmed over flooding and land erosion. (Update: Officials released a 2018 report late Friday in which an engineer warned of “major structural damage” to the concrete foundations of the building.)

"According to a Florida International University professor who co-authored a study focused on the issue last year, the complex had been sinking into the earth bit by bit since the 1990s, at one point at a rate of about 2 millimeters per year. 

Professor Shimon Wdowinski and co-author Simone Fiaschi were examining increases in flooding frequency, and found that in addition to rising sea levels, flooding was 'significantly higher' in areas along the southeastern coast that had been sinking into the earth due to urban development and compacted sediment on what was (at least in part) reclaimed marshland."

https://www.thedailybeast.com/ill-fated-champlain-towers-showed-signs-of-something-off

Over the last 20 years OSHA has investigated 67 incidents of significant structural failures. 15 happened in Florida - over ten times the national average.

Even without settling, the expense of protecting electrical cables in areas repeatedly flooded by corrosive saltwater will make undergrounding more impractical than it is already. But it may not matter - within a century most of Florida will be uninhabitable anyway.

Doug Houseman is correct about the cost of going underground. Instead of adding to that question, maybe we ought to think of a different way of building a Smart Grid. Microgrids in areas where transmission costs are high due to distance from generation facilities, storage and things like what Vermont Electric are doing using wind, solar, Tesla Powerwalls and more. There are much more creative and more resilient and reliable ways to build it, rather than think the current transmission system is the best, even if it were underground. 

If there were forthcoming TRILLIONS then this is a great discussion. 

Underground transmission costs about 6 times the overhead costs in rural areas, and as much as 12xx the cost where there is a population center. 

 

Distribution costs are about $3 million/mile in suburban areas, 3x that in urban areas, and about 2 for rural areas. - there are 5.5 million miles of distribution - $165,000,000,000,000 - this is more than the whole Federal Debt. The numbers are averages from filings by various utilities in various states. Work in Florida shows that costs can be reduced, but even if we had a 75% reduction in costs it would still be trillions. 

 

Undergrounding needs to be strategic and carefully done. 

The cost of such a move would be absolutely staggering, as we have thousands and thousands of miles of transmission lines. Just a really bad idea from a cost versus benefit for the country as a whole. From a security standpoint, the vulnerability is greatest at those points where digital protective relays and switching controls exist that can be accessed and controlled remotely by computer. While having the ability to program and control the relays is good from a technical standpoint, that convenience comes at a security cost. The communications systems with these relays needs to be significantly hardened to minimize hacker and terrorist remote access.

Larry, from what I understand it all comes down to expense. Though security and visual aesthetics are improved by burying cable, installation and maintenance are more expensive - and dangerous. A careless backhoe operator, for example, can quickly take a distribution grid down and seriously (or fatally) injure himself.

Proponents point to Europe, where "undergrounding" is common. But for the same reason a higher percentage of residents ride bicycles in Amsterdam than Los Angeles, the sheer size of American communities would make burying cable prohibitively expensive.

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