About Carbon Fiber / Composite Core Conductors

Carbon and Composite Core Conductors, also known as Advanced Conductors or High- Temperature, Low-Sag (HTLS), are overhead, bare conductors that use a trapezoid shaped wire of annealed aluminum to carry electrical current and use a carbon or composite core for support. Used commercially for 20 years, the conductors are deployed in over 60 countries across 5 continents.

Carbon and composite core conductors have three key advantages over traditional (ACSR) conductors:

  • Have stronger and lighter weight cores, which allows for more aluminum to be added to the conductor, doubling the capacity;

  • Are 20% or more efficient;

  • Have half as much thermal sag.

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Diagram of a High Performance Conductor, showing the structure with trapezoidal outer strands of fully annealed aluminum and a smaller yet stronger core made from composite materials.
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Case study #1: AEP West — Texas Lower Rio Grande Valley (2011)

  • Challenge: AEP West faced significant load growth in South Texas but was informed by ERCOT that the transmission line could not be taken out of service long enough to accommodate a full rebuild.

  • Solution: AEP reconductored approximately 240 miles of aging conductors with HPCs using energized (live-line) installation techniques that kept the line in service throughout construction. Doubled the line’s capacity and reduced line losses by 30%, saving $15 million annually.

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Case study #2: Montana-Dakota Utilities — Montana (2021)

  • Challenge: The utility needed to upgrade aging infrastructure in a region with harsh winter conditions, including 1.5 inches of ice loading, while minimizing costs and avoiding lengthy rebuild timelines.

  • Solution: Montana-Dakota Utilities selected HPCs for reconductoring using existing towers, which were uniquely capable of withstanding the region’s ice loads and allowed for rapid deployment. Increased capacity by 50% while achieving 40% cost savings compared to rebuilding with traditional ACSR conductors

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Case study #3: Southern california edison — BIg Creek Corridor (2016)

  • Challenge: SCE needed to upgrade a critical transmission corridor in a wildfire-prone area, and traditional rebuilds would have delayed the project by years.

  • Solution: The utility reconductored the line with HPCs, which offered a lighter, low-sag carbon core that provided both higher capacity and improved wildfire resilience. Doubled transmission capacity, saving customers $85 million and shaving 30 months off the construction schedule when compared to building with traditional ACSR.

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