Why Can’T We Bury Power Lines?

The question of why we can’t bury power lines is an important one, as severe weather events like hurricanes, ice storms, and wildfires frequently cause power outages when overhead lines are damaged or destroyed. Burying power lines underground could prevent these outages and provide more reliable electricity service. However, there are significant challenges and costs associated with transitioning to an underground power grid. This article will provide an overview of the key factors involved in the debate over burying power lines.

Pros of Burying Lines

Burying power lines underground offers several potential benefits compared to traditional overhead power lines:

Improved reliability: Underground lines are less susceptible to damage and outages from severe weather events like storms, high winds, ice, and snow. Trees falling on lines is a major cause of power outages that is eliminated with buried lines [1].

Reduced outages: Because they are protected, buried power lines have fewer outages resulting in more reliable electricity delivery. Areas with underground lines experience 70-90% fewer outages than overhead lines [1].

Enhanced aesthetics: Removing unsightly poles and overhead wires can greatly improve the appearance of neighborhoods and landscapes. Underground lines also enable better city planning and development.

Cons of Burying Lines

Burying power lines comes with some significant drawbacks. The most notable is the high upfront cost. Installing underground lines can cost up to $1 million per mile, while stringing overhead wires only costs $100,000 per mile (https://winknews.com/2019/04/04/can-burying-power-lines-keep-the-lights-on-during-powerful-storms/). This 10x increase in infrastructure costs presents a major barrier.

Accessing buried lines for maintenance and repairs is also much more difficult compared to overhead wires. Any issues require excavating to reach the cables, leading to longer outages. Flooding can also damage underground wires, contrary to the perception that buried lines are immune to weather events (https://www.city-data.com/forum/florida/2874164-puerto-rican-arrivals-florida-hit-hard-times-4.html). The vulnerability to flooding mitigates some of the benefits.

Cost Comparison

The cost to bury existing power lines underground is significantly more expensive than installing overhead power lines. According to homeguide.com, burying power lines costs between $2,000 to $6,000 per linear foot, while overhead power lines cost $20,000 per mile on average. This means it can be over 30 times more expensive to bury lines underground.

For example, the typical cost to bury a one mile length of power line underground is around $528,000. In contrast, stringing one mile of overhead power line costs approximately $80,000. While exact costs vary by region and project specifics, these comparisons illustrate the large price differential between the two methods.

One report from FEMA showed a project that buried 5 miles of overhead lines at a cost of $11,570 per mile, totaling $57,850. While expensive, proponents argue the increased reliability and resilience of buried lines can justify the higher upfront costs over the long term.

Feasibility

Burying power lines comes with several technical and regulatory challenges that make large-scale implementation difficult. According to a report by Oklahoma Gas and Electric, burying all power lines could take over 20 years to complete (source).

On the technical side, burying high voltage transmission lines requires special insulation and cooling systems to prevent overheating. Underground lines are also more prone to failure and much harder to access and repair. Any fault in an underground cable often requires excavation to locate and fix the problem.

There are also regulatory and legal obstacles around rights of way and obtaining permits for underground construction. Rerouting existing above-ground lines underground would require cooperation from multiple jurisdictions and property owners.

According to an Austin City Council report, the complex web of regulations from various authorities like the Public Utility Commission and ERCOT creates additional challenges (source). New legislation may be needed in some areas to facilitate large-scale undergrounding projects.

Case Studies

One example of a city that has buried power lines is Washington, D.C. According to the Quora article “What cities and states have underground power lines?” (https://www.quora.com/What-cities-and-states-have-underground-power-lines), Washington, D.C. began a project to bury power lines after a 1922 blizzard knocked out overhead power lines. Today, 90% of the city has underground power lines.

Burying the lines has significantly improved reliability in D.C. During hurricanes and storms that cause widespread power outages in surrounding areas, most of D.C. retains power. According to Pepco, its utility provider, “underground equipment is less susceptible to damage from storms and severe weather than overhead lines.” Outages in D.C. tend to be fewer and shorter compared to cities with above-ground lines.

Another case study is Fort Collins, Colorado. As reported by the Colorado Springs Gazette (https://gazette.com/news/fort-collins-buried-all-its-power-lines-so-can-colorado-springs-cronin-loevy/article_51bf5af8-8a05-11ec-815c-431ed60d6ac1.html), Fort Collins buried all of its power lines over an 18-year project completed in 2006. This has significantly improved reliability, with Fort Collins now seeing fewer and shorter power outages than other parts of Colorado.

New Technologies

There are some exciting new technologies being developed that could make burying power lines more feasible in the future. One innovation is the use of covered power lines. These involve encasing traditional above-ground lines in insulated coverings to help protect them from weather events and animals. The covers provide many of the same benefits as buried lines, like reduced outages, without the major upfront costs of undergrounding.

Another promising technology is underground power lines that use access panels or vents to allow maintenance workers to reach the lines for repairs. Traditional buried lines are very difficult to access when issues arise. But lines with built-in access points avoid the cost of completely excavating and reburying lines for routine maintenance. This can make underground power more affordable while still keeping its reliability advantages.

Policy Considerations

There are some key policy considerations around the debate of burying power lines versus keeping them above ground. Two major factors are government funding challenges and public support.

Burying existing above-ground power lines would require massive infrastructure spending by federal, state, and local governments. According to the U.S. Department of Energy, burying above-ground lines costs approximately $1 million per mile, compared to $100,000 per mile for overhead lines. With over 200,000 miles of high-voltage transmission lines alone in the U.S., the costs to move lines underground would likely reach into the hundreds of billions. Securing adequate funding for such large public works projects presents a significant challenge.

Public support is another key factor. Residents may desire the aesthetic improvements and reliability benefits of buried lines, but not support major rate increases on their monthly utility bills to fund the projects. Strong public information campaigns would likely be needed to educate citizens and build support for any major initiatives to bury substantial portions of above-ground grid infrastructure.

Policymakers weighing proposals to bury lines must carefully consider funding constraints and public sentiment. Though burying key portions of the grid may provide benefits, the high costs involved mean it is not a straightforward decision.

The Future

Despite the many challenges and upfront costs, the trend towards burying more power lines underground is likely to increase over time. As this article discusses, improvements in underground cable technology like high-temperature superconductors and solid dielectric cables may help reduce the costs and feasibility challenges in the future. Many experts believe that burying lines underground is the inevitable future of electrical infrastructure for developed areas that can afford it, offering benefits like reliability, aesthetics, safety and maintenance cost savings.

However, overhead power lines will likely remain prevalent, especially in rural areas where cost is a bigger barrier. Burying all utility lines underground nationwide would require massive capital investment measured in the trillions of dollars. But as technology improves and cities and communities make investments over time, we may see a gradual shift towards burying more power lines where it makes the most sense based on cost-benefit analysis and community priorities.

Conclusion

In summary, burying power lines underground has some advantages but also significant downsides that must be carefully weighed. Burying all power lines would provide more resilience against storms and natural disasters, less risk of electrocution, and more aesthetically pleasing views without overhead wires. However, it comes at an extraordinarily high cost likely in the trillions in the US alone, would require a massive infrastructure project, provides challenges for maintenance and repairs, and is not feasible everywhere due to geography and existing urban density.

There are merits to targeted undergrounding of new lines or areas especially prone to storms, but a full transition is likely cost prohibitive. New technologies like covered conductors may provide a middle ground but are unproven long-term. Overall there are no easy solutions, and communities must consider all tradeoffs involved when evaluating burying versus overhead power delivery.