Advanced transmission cable projects still on the sidelines

By Peter Behr | 04/10/2024 06:52 AM EDT

The conductors are less vulnerable to overheating and could move more energy across the U.S. electricity system, according to studies.

Power transmission lines are shown in Lansing, Michigan.

Power transmission lines are shown in Lansing, Michigan. Al Goldis/AP

Almost a year ago, Secretary of Energy Jennifer Granholm held a high-voltage cable in her hand and explained how it could be used to significantly increase the capacity of the U.S. electricity system.

But her message during last June’s visit to a technology lab in North Carolina has been slow to get through.

Advanced transmission cables built with aluminum-sheathed carbon fiber or other composite cores are lighter and stronger than traditional aluminum-wound steel core cables, and thus they can carry up to four times more current, according to a series of studies, the newest released this week by the University of California, Berkeley, and GridLab, a research group supporting clean energy policies also based in Berkeley.


But the upfront costs for newer cables — two to three times more than comparable conventional lines strung in new transmission projects — have kept them on the sidelines.