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.
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Technical Bulletin - Undergrounding: Hidden Lines, Hidden Costs
Overview of the costs and other challenges placing utility lines underground. Includes cost comparisions of underground lines vs. overhead systems with utility poles.
8 pages, 4/17 |
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Out of Sight, Out of Mind 2012
2012 update of Edison Electric Institute study of the costs of undergrounding overhead power lines.
71 pages, 1/13 |
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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 |
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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 |
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UPDATED! DIRT Report on striking underground utilities
Report from Common Ground Alliance on the record 534,151 events in North America where underground utilities were struck or damaged during 2019.
65 pages, 10/20 |
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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 |
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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 |
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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 |
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