Expense Pains of Underground Power Lines
Updated: Oct 31, 2020
Clarksville, TN (CU) - If you ask enough people, you’ll hear billboards are the number one eyesore of any urban community. But overhead wires and service poles have also been creating a very unattractive sight line for an exceptionally long time. We’ve just gotten used to the sight of them over the years.
More than three million miles of electrical cables cover the US with nearly 200 million telephone and cable lines hovering above ground on power lines. As a result, the aesthetics of our communities are often populated with repetitive views of utility wires and poles. When you’re referencing fast growing areas, such as Clarksville – Middle Tennessee, the importance becomes amplified.
Because of benefits associated with under-grounding utilities most new subdivisions bury utility lines. In addition, cities across the US have developed plans to bury utility lines. Even with that proactive planning, established areas are left behind in the development phases.
To put it bluntly, utility wire under-grounding and relocation projects are expensive. Communities need to convince their local officials and utility companies of the benefits of wire relocation or burial. On a larger scale, utilities report that it often costs five times more to install underground power lines than overhead lines. The trade-off, in terms of cost and other impacts, comes when severe weather events cause significant damage to overhead power systems, requiring costly repairs and economic hardship due to prolonged power outages.
Overhead service feeds include power poles that string feeder wires from the utility company’s pole to the power pole by your home. The appearance of an area can be greatly improved by reducing the visual clutter of utility wires. The appearance aspect provides a sense of community pride and acts as an asset for recruiting new members or businesses to the area. Under-grounding utility wires provides communities the opportunities to highlight their unique beauty without spiderwebs of poles and wires dominating the skies. Side benefits of removing overhead utilities have been tied to improvements with the process of improvement projects. These improvement projects, such as sidewalk widening and tree planting, become easier to manage without an additional effort to snake around poles or maintain vegetation.
Upkeep and Maintenance
In Middle Tennessee, we experience all beautiful collection of a full four seasons. As a result, the weather can be our enemy at times. Falling trees, high winds, and heavy snows are just a few of the things frequently creating utility disruptions by damaging overhead lines. Burying lines eliminates weather-related power outages and provides more reliable service to subscribers.
Burying lines is a significant contributing factor towards eliminating fire hazards, accidents, and safety risks due to downed lines. Relocation of power lines also reduces the potential health risks associated with electromagnetic radiation while improving road safety by reducing the chance of vehicles striking poles. Or, if you watch a lot of YouTube, people walking into poles.
There are revitalization experts across the country preaching the positive investment benefits with the appearance. Changes in the traditional commercial areas can be one of the best ways to attract new business and stimulate economic development.
This all sounds too good to be true. What are the downsides? There are two different ways of removing poles and taking utility cables underground. The least expensive way is called open trenching, where utility companies dig and lay strings of utility networks as they back fill the trenches later. This often requires rerouting of traffic which can present its own challenges.
You'll often find communities choosing directional drilling. This process is borrowed from an old oil and gas technique of drilling. Directional drilling is a less invasive, but more expensive, option for burying underground utilities. Installers can simply drive a pipe through a planned, miles-long subterranean channel without disrupting daily street level activities.
Either way, wires hanging from the above ground poles aren't available for underground use without modifications - the most important aspect being insulation. Electricity wires are very warm by the simple nature of their purpose - channeling currents back and forth. In the open air of above ground poles, this developing heat can dissipate into the air, but confined in the soil it doesn’t lose the heat. That’s the reason utilities are insulated and wrapped in plastic and surround with a conduit like oil to keep the equipment from overheating.
It's an assumption that every tractor owner in Guthrie and Ashland City would be ready to start the process tomorrow for a small fee. But wait! Depending on the density of the local population and the topography, and Middle Tennessee is very hilly, the project could cost 10s of millions. An article in The Conversation, Theodore Kury gave the example of communities having reviewed the expenses of under-grounding and decided change wasn't worth the price. In North Carolina, the approximately 25-year-long process of under-grounding the entire state's utilities would raise electricity prices by 125 percent. On the reverse side, Washington, D.C., has made the decision to underground a portion of its utility wires at an expected cost of $1 billion and local rate increases.
That’s not the only cost prohibitive aspect either. It just keeps going the wrong direction, huh? Repairing underground power line systems is typically more expensive than repairs for above ground wiring. “When the power goes out, there are two obstacles that [utility] faces before they can fix the line," Kury says. "One, identification of the fault, and then two, access to the line." While smart grid technology makes identification easier—devices would be able to identify the utility issue's exact location within the system. Although now you're going to experience access to those underground systems being hindered. Repairs require disruptive digging projects, which can be impacted by seasonal weather such as frozen grounds, flooded areas, or high winds. In the end, neither system can protect power in every situation.
The next time you’re taking a ride through town, look up. Are those wires worth the cost of replacing or have they slipped even further down the priority list?