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Undergrounding

Wood Poles vs. Undergrounding

Undergrounding

Moving overhead power lines underground is often advocated as a way to decrease power outages caused by weather or other events. 

However, placing power lines underground -- particularly if relocating existing overhead lines -- carries significantly higher costs without a corresponding improvement in reliability of electrical service.

The first utility poles, ordered by Samuel Morse in 1844 for his new telegraph line from Baltimore to Washington D.C., were created after Morse placed the lines underground and experienced multiple failures.

The decision to place lines underground is usually not because of issues with utility pole performance. In most cases, lines are put underground for aesthetic reasons so they won't be seen.

Many studies indicate the cost to convert overhead lines to underground lines at five to 10 times that of comparable overhead construction using wood poles. Also, failures in underground lines can take significantly more time to identify and repair compared to overhead line repairs.

Review the following for additional information on the economics and service reliability of overhead lines compared to placing lines underground.

Undergrounding

OSO2 Out of Sight, Out of Mind Revisited
2009 update of Edison Electric Institute study of the costs of undergrounding overhead power lines.
66 pages, 12/09
PDF
OSO1 Out of Sight, Out of Mind
Original 2003-06 Edison Electric Institute study of the costs of undergrounding overhead power lines.
32 pages, 07/06
PDF
TBHardening Technical Bulletin - Hardening of Utility Lines: Implications for Utility Pole Design and Use
Despite calls for "hardening" utility systems in response to storms, qualitative evaluations indicate current sytems perform as expected and potential actions to harden the system are expensive and offer questionable benefits.
8 pages, 11/07
PDF
Dirt2014 DIRT Report on striking underground utilities
Report from Common Ground Alliance on the 273,599 events where underground utilities were struck or damaged during 2014.
32 pages, 09/15
PDF
Laguna Laguna residents fight undergrounding
Residents in Laguna, Calif., discover the high costs of moving utility lines underground.
2 pages, 05/09
PDF
Fla Florida Utilities Research: Undergrounding Electric Lines
Three-part report analyzing the costs of placing utility lines underground vs. the marginal benefits in protecting distribution systems.
Phase 1 - Literature Review and Analysis - 40 pages, 02/07
Phase 2 - Case Studies - 40 pages, 08/07
Phase 3 - Ex Ante Cost and Benefit Modeling - 97 pages, 05/08
PDF
Texas Cost-Benefit Analysis of Hardening Utility Lines
Report by Public Utility Commission of Texas analyzing costs and benefits of placing utility lines underground.
10 pages, 03/09
PDF
Mara Cost-Effectiveness of Undergrounding Utility Lines
Presentation by Kevin Mara, PE, of HiLine Engineering on the trends and economic costs in placing utility lines underground.
16 pages, 10/06
PDF