By Tim Gardner
While the new transmission line constructed to connect the electrical substations between Sugar Mountain and Banner Elk in Northern Avery County didn’t meet its anticipated completion timeline of summer or early fall of 2019, it has been operating since November last year. And it has been a godsend of electrical sorts to those using electricity in its service area.
According to Mountain Electric Cooperative General Manager Joseph (Joe) Thacker III, the Sugar Mountain transmission line and substation provides long-term benefits to electric consumers in its region who are served by Mountain Electric.
“The Sugar Mountain Substation and Transmission Line are necessary to maintain adequate electric power capacity and service reliability in the Sugar Mountain, Banner Elk and Grandfather Mountain service areas,” he commented. “Additionally, the new facilities improved electrical service capacity conditions in the Linville area due to the electrical load that was transferred from our Linville Substation to the new Sugar Mountain Substation when it became operational.”
Thacker III added: “Although we didn’t get the transmission line operating by the time frame we wanted due to some delays, it has been so beneficial to its service area and our officials and staff are proud of it.”
Mountain Electric Cooperative was formed on April 1, 1941 by area farmers and residents. It owns and operates more than 2,290 miles of distribution line and over 24 miles of transmission 69 kV lines. MEC distributes electricity, generated by the Tennessee Valley Authority, to more than 33,900 residential and business members.
The Mountain Electric service area includes primarily Johnson and Carter Counties in Tennessee and much of Avery County. Additionally, small portions of Watauga, Burke and Mitchell, NC counties and Unicoi County, TN are also served by the cooperative.
The MEC service area population is approximately 45,000 and covers 700-square miles. The cooperative has several dozen full-time employees based out of three offices, including its headquarters in Mountain City, TN, a district office in Newland, NC and a small branch office in Roan Mountain, TN.
In 2018, Mountain Electric Cooperative began construction on the Sugar Mountain 69,000-volt (69 kV) Line to connect a new electrical substation in the Village of Sugar Mountain to its 69 kV electrical grid near its Banner Elk Substation. The new substation was designated as “The Sugar Mountain Substation.”
The project’s right-of-way preparation was completed by the end of August 2018. Holes were started being dug for the line in March of that year and then pole installation began shortly after. All poles at the substation are made of solid steel and were assembled on site. Some are massive in height, reaching more than 100 feet. And nearly 60 structures are part of the project–some of which include more than one pole.
The Sugar Mountain Transmission Line was built within a 75-foot wide linear right-of-way easement owned by Mountain Electric. The length of the line is approximately 4.15 miles, which includes approximately 3.0 miles of acquired right-of-way within which it was built. It also includes an approximate 1.15-mile portion of an existing Mountain Electric transmission line right-of-way easement that runs between the Towns of Banner Elk and Newland.
Mountain Electric officials said that the installation process was highly- challenging due to the complexity to the mountainous region and sensitive environmental resources that are present in the general vicinity of the line’s route.
They also revealed that twelve alternate routes were analyzed before selecting the final route to confirm that line construction could be achieved in a safe manner and while some of the lines installed cross roadways, most are off roads.
Thacker noted that Mountain Electric officials carefully planned each phase of work with the ultimate goal of balancing two critical objectives–protecting environmental, cultural and scenic resources in the area and selecting a line route through tough, mountainous terrain that facilitated construction and long-term maintenance.
When siting the route for the line, comprehensive environmental, cultural and scenic resource studies were conducted that allowed consideration of only those routes that would avoid or minimize any effects to them. While conducting those studies, Mountain Electric also carefully analyzed terrain conditions along the alternate routes.
The initial phase of line construction, which began after Mountain Electric received all required project permits, included clearing trees from the right-of-way, installing extensive erosion and sediment control measures and building access roads that accommodated line construction, line maintenance equipment and vehicles.
Also, besides the installation of line structures (single steel poles, for the most part), the project included stringing the conductors (three current carrying conductors and one overhead ground wire).
The final construction phase was “clean-up and repair” that focused on repairing any minor disturbances to the ground surface within the right-of-way and access roads that may have occurred while installing the structures and stringing the conductors.
Mountain Electric Cooperative officials said the initial phase of work such as preparing the right-of-way, was especially challenging and the company took extra care to assemble a well-qualified corps to perform this work. That included a contractor who specializes in right-of-way preparation and has executed numerous successful projects in mountainous areas.
The electric cooperative also engaged an experienced project inspector to work with the contractor to ensure all permit requirements pertaining to environmental protection were fulfilled.