Underground vs. Overhead Power Lines
There are two methods of installing the power lines that carry electricity to your home, overhead and underground. Lane Electric Cooperative members sometimes ask why we use one versus the other, or why all power lines are not installed using the underground construction method. These are great questions, and the answer is that each method has its place.
Let’s look at some the advantages and disadvantages of each method.
Overhead
Overhead line construction starts with the setting of utility poles. Poles can be set in nearly any type of terrain, and are less expensive to build and maintain. Overhead lines are also easier to locate, and repair faults or damage. Once the poles are in place, wires can be strung and equipment installed.
Overhead lines are, however, more susceptible to extreme weather conditions, like wildfires and ice storms. As a part of our advanced wildfire mitigation planning, we are exploring additional options to make our system even more resilient, such as pole wraps, coated power lines and relocating overhead lines to less sensitive locations.
Pros:
- Less expensive to build and maintain
- Easier and quicker to locate and repair faults or damage
- Can be built in any terrain
- Faster construction time
Cons:
- Exposed to wind, wildfire and weather, including ice
- Susceptible to damage from trees and vegetation
- Vulnerable to blinks when animals and branches contact lines
- Risk of damage from vehicles colliding with power poles
- Possibility of contact with energized downed lines
- Less attractive
Underground
Underground line construction requires digging a trench that is deep enough to keep the lines well away from surface activities, like digging or construction. Where the terrain is extremely rocky, underground lines may not be an option. Wires are then laid in the trench directly or placed in conduits for protection. Currently, Lane Electric has more than half of our distribution system (754 miles of line) underground, which is significantly higher than the national average.
While underground lines are protected from wind, wildfires and tree branches, they are vulnerable to earthquakes and flooding. They are also more expensive to build and maintain. By comparison, it costs approximately 3-5x more per foot to construct underground power lines versus overhead lines. Furthermore, it would cost in excess of $600 million to bury the remaining overhead lines in our service territory. In order to avoid passing that cost onto our members, we continue to apply for FEMA grants to underground more of our system each year.
Pros:
- Protected from wind, wildfire, weather, tree branches and damage from most animals.
- Less susceptible to outages from vehicles colliding with poles.
- Reduced risk of electrocution from downed lines.
- Aesthetically more pleasing, with poles and wires out of sight.
Cons:
- More expensive to build and maintain.
- Time consuming and expensive to locate and repair a malfunction.
- Vulnerable to damage and electrocution from digging or other construction.
- Susceptible to damage from earthquakes and flooding of the transformer box.
- Not practical in unstable sandy or rocky mountainous areas.
- Ultimately fed by overhead lines.
What is Lane Electric doing?
Trees are the number one cause of outages in our rural service territory. Our tree-trimming program is staffed with arborists and forestry experts who work tirelessly to keep our members safe and reduce the chance of power outages. Our tree crews are constantly trimming and removing trees under power lines in our ongoing effort to make your electric service as reliable as possible. In addition to tree trimming, our crews perform regular equipment maintenance and take planned outages as necessary to repair or replace equipment.
Additionally, we are actively applying for FEMA grants to move as much of our system underground as is feasible and mitigate the extreme weather risks above-ground power lines are susceptible to. We are committed to doing so as effectively as possible and at no-cost to our members.
What can you do?
You can help by taking a “power friendly” approach in landscaping your property. Choose the right tree, plant it in the right place, and maintain it. Members are responsible for making sure trees aren’t growing into the line that comes from our distribution system to your house. If limbs are getting too close, contact us at 541-484-1151 and we will make arrangements to come and drop your service line for you while you trim the trees. Together, we can all do our part to build an even more resilient system. Visit our tree trimming page for more information.