What Are the Pros and Cons of Underground Power Lines?

Professionals such as city planners and electrical engineers often discuss the pros and cons of underground power lines versus those above ground. Becoming familiar with their advantages and downsides enables making more-informed decisions and engaging in authoritative conversations with clients and other stakeholders. 

Increased Costs Associated With Underground Power Lines 

One of the main arguments against burying power lines is that they’re more expensive than their above-ground counterparts. Overhead power lines are pricey, too. They cost approximately $100,000 per mile to string. However, underground versions can be 10 times that amount. 

There are also associated costs when a community has overhead lines and people plan to transition to the underground type. However, the extra expense may be worthwhile depending on why residents want this kind of infrastructure. 

Outages Happen Less Often With Buried Lines 

Downed power lines can cause major infrastructural challenges for power companies. They also wreak havoc on consumers, especially when households have medical needs or other characteristics that make them particularly dependent on reliable electricity. Placing lines underground does not prevent outages. However, decision-makers at some utility providers believe it could substantially reduce them. 

In Virginia, authorities at Dominion Power are working on a long-term undergrounding project. So far, 46,000 customers have had their lines put underground. That change benefitted the whole grid and prevents 2,500 outages annually. Representatives say the power company can now devote more resources to fewer overall problems. They’re also specifically burying the lines that were historically most prone to outages. 

Virginia’s utility regulator conducted a study about the financial feasibility of underground power lines in 2005. The results confirmed that they would reduce the adverse effects of lost sales and post-storm restoration during outages. Moreover, burying the lines would eliminate tree-trimming maintenance. 

However, the benefits would not offset the costs. That’s because each Virginian would need to pay $3,000 (approximately $4,915 in today’s money) to make a complete undergrounding project happen. 

Underground Power Lines May Require Special Placement Considerations

People can easily see the locations of above-ground lines, but that’s not the case with those placed underground. Thus, there’s an elevated likelihood of machines such as diggers accidentally hitting and damaging them. 

However, the need for pre-project planning to avoid those issues is not unique to laying underground lines. People also must do it when drilling pipelines, especially since many projects happen in residential areas. The pre-planning phase often reveals solid rock, requiring drilling and blasting during excavation. 

The hidden nature of underground power lines makes them good choices for places where people don’t want to interfere with a site’s aesthetic or historical characteristics. One recent example involved people burying more than five miles of power lines in Dorset, England, at a protected area. Archeologists unearthed artifacts from more than 6,000 years ago on the land. 

People involved with the line burying also mentioned that the site had such steep slopes that it needed special machinery and required workers to anchor diggers before using. 

Underground Cabling Supports Solar Power

Many experts assert that modern society must aggressively transition to renewable energy to make the world more sustainable and ready for the future. The benefits go beyond helping the planet, too. Statistics indicate solar panels could reduce utility bills by as much as 75% for some businesses. 

Solar panel installations require cables to work, and people can put them underground, too. One project involving a United Kingdom hospital and its more than 15,000 solar panels will use below-ground cabling to connect the facility with a solar farm. Installing the cables should take about four months. 

Many people are interested in using solar power for numerous reasons. They typically see the panels on rooftops, but this example shows that the infrastructure can sometimes remain underground, too. 

Putting Lines Underground Can Be a Climate Change Safeguard

A large and increasing body of research suggests climate change will lead to more extreme weather events. Representatives at some utility companies have already noticed that their power infrastructure cannot withstand this trend. During one summer in Michigan, the state experienced nearly 20 major storms that left 2.4 million people without power. Some of them were in the dark for more than a week. 

That issue caused the state attorney general’s office to assert that utility companies should compensate customers for such inconveniences. Experts have also noted that state officials must act now to prevent future occurrences. Burying power lines is one option, despite its associated expense. Advocates say that underground lines are safer for the public and would be more resilient. However, any work on them would take longer to complete than on overhead lines. 

A worrying report also warned that wildfires will become more severe and widespread due to climate change. It suggested worldwide catastrophic wildfires will show a one-third increase by 2050. The data also warned that this trend will also adversely affect areas historically thought of as well-protected. 

People assert that burying lines can virtually eliminate their ability to start fires. As of now, many utility providers compromise by turning the power off during periods of high wildfire risk. 

One of the major downsides of undergrounding, though, is the slowness of the process. One California utility company started putting lines underground in the 1960s and, until recently, had a goal of burying 15 miles of lines throughout San Diego each year. However, with undergrounding part of its wildfire mitigation plan, the amount should surpass 100 miles annually by 2023. 

Installing Lines Underground Requires Careful Consideration

Utility providers that want to make their electrical infrastructure more resilient should consider installing lines underground instead of above. However, it's not the best solution in every case due to factors such as the cost and significant time required.

Another issue is that regulations associated with the land may make it unsuitable for undergrounding the lines, or it could take planners significant time to get approval. Similarly, it’s necessary to engage with property owners when the underground infrastructure would include privately owned lands. 

Costs are typically passed onto the taxpayers. Most people would appreciate fewer power outages, but they may be less agreeable to the money needed to accomplish that goal. These factors highlight why it’s hard to decide quickly whether to put this infrastructure under or above ground. Both options have essential advantages and disadvantages to weigh.