RANDOLPH — Eversource is investing roughly $26 million statewide this year on installing optical ground wire, a dual-functioning cable that makes the electric transmission system both more resilient in severe weather and enhances vital communication between key installations, such as substations, providing real-time information on its electric system.
William Hinkle, Eversource’s media relations manager in New Hampshire, said in an email exchange: “The optical ground wire — OPGW — is placed at the topmost position on the transmission line (towers) where it protects important equipment from lightning with the added benefit of containing optical fibers to transmit data."
“Optical ground wire projects are an important part of improving grid reliability,” said Eversource Director of Transmission Construction Marc Geaumont in a prepared statement.
“This work provides a stronger electric system, not just for Eversource but to the whole electric grid and allows us to better deliver electricity to the neighborhoods where we work and live.”
OPGW also allows Eversource to reduce how long power outages last when they do take place.
Over the summer, a chunk of Eversource’s statewide investment was made in the southern tier of Coos County.
Several helicopters plus other equipment worked over and on the upgraded transmission powerline corridor between the East Side substation on the edge of the Community Field in Berlin and the Whitefield Substation off Route 3 north of King’s Square, which required crossing through those two municipalities plus the towns of Gorham, Randolph and Jefferson.
The OPGW installation was performed mostly by helicopter, but in order to perform this work safely, crews had access to certain structures from the ground. Four contractors worked on this phase of the project: Michels Power, Supreme Industries, Haverfield Aviation and Waveguide.
Ground crews used bucket trucks, cranes and ATVs. Reusable wood mats were temporarily installed to reduce harm to brooks and wetland areas. Construction hours lasted from 7 a.m-7 p.m., Monday-Sunday.
“We now expect to finish the helicopter work by early October, with some remaining restoration and ground work to follow before completing the project later this fall,” Hinckle said.
Elis Ward, Eversource Siting and Construction Services Specialist, pointed out reassuringly, “When the project is complete, crews will restore areas that were disturbed by the work.”