Preamble: Utilities are highly risk adverse. They are generally not quick to try new things. An old saying goes: “They all want to be first to be second.” Meaning that they want someone else to learn any hard lessons before they adopt any new technology but may still want to be identified as leaders.
Background: Several decades ago, non-ceramic ‘polymer’ insulators were introduced that used improper glass fibers, less than adequate manufacturing methods, and poorly designed connectors. Moisture that penetrated into the fiberglass rods through the connectors wicked into the core. This, coupled with the electrical potential to ground and highly charged electric fields, acidified the moisture which ate away boron in the glass resulting in brittle fracture and premature insulator failure.[1] At that time, the science was new, not well understood, and lacked manufacturing and test standards. With tens of thousands of these devices in service, it was a hard lesson to learn for many utilities. A decade or so later a handful of utilities installed ‘self-damping’ ACSR conductor with less than stellar results and replaced these conductors relatively quickly. Nebraska Public Power District reported several failures of 954 kcmil ACSR SD wire from 2010 to 2012. With 2,000 miles of wire in the air, they took a different approach as described in a thesis by a student at the University of Nebraska. In any case, the prerequisite to successfully using any new technology requires significant testing and a full understanding of the product’s attributes and limitations.
Discussion: While much has been learned since the introduction of self-damping conductors and polymer insulators, and many improvements made, risk mitigation requires knowledge and facts. CTC Global’s development and testing of the ACCC Conductor and its composite core benefitted tremendously by the decades of experience its founders leveraged to embark on their journey. This was further strengthened by the strong support of several key utilities like Southern California Edison, American Power, PacifiCorp, and many others. The inclusion of the ACCC Conductor in testing and evaluations by EPRI[2], members of IEEE[3], Cigre[4], a vast number of university professors and students, including the collaboration with the National Science Foundation, gave CTC, its product, and its customers a strong advantage - and much is known.
Facts: In addition to the testing and evaluation of the ACCC Conductor and composite core completed by CTC and others, lessons learned in the field have delivered much more knowledge about proper installation techniques and how well the product performs under varied conditions. In 2006, crews in China installed Drake size ACCC conductor over a mountain range with several spans over 2,500 feet. Two days before the line was energized, Typhoon Kaemi brought in 2-4 inches of rain and 75+ mph winds. A few days later, Typhoon Saomai delivered winds in excess of 135 mph. More than 1.3 million people were evacuated. Fortunately, the 220 kV ACCC conductor was unaffected which was looked upon very favorably by the utility as this line traversed over 37 other T&D lines and a line failure could have had dire consequences. See Report. In 2012, a firestorm took down several wood structures supporting 431 kcmil Linnet ACCC Conductor. While several structures had to be rebuilt, the ACCC Conductor was undamaged (watch video interview). Since that time NV Energy has completed more than 30 additional new line and reconductor projects in its service territory with great success. Many similar stories can be found on CTC Global’s website and blog posts.
Conclusion: As with any new piece of equipment or device, it is important for the user to understand the product’s characteristics and limitations. CTC Global offers an impressive array of support for everyone in the process ranging from transmission planners and engineers to asset managers, maintenance crews and installation teams. The ACCC® Conductor was designed to mitigate risks common to grid owners and operators. The technology, and composite materials in general, have been widely proven and accepted to deliver higher performance, lower risk, and improved longevity. In addition to having successfully completing over 1,250 projects in 66 countries, it is noteworthy that there are over 75 CTC certified ACCC Master Installers, worldwide. The experience and knowledge they share with utility crews has helped CTC deliver a ‘no regrets’ conductor solution for every project type. As Tom Martin described in a recent article “the way we’ve always done it” may now be the riskier approach.