It's About Time: A Power Line That Sheds Heavy Ice

Tired of Jack Frost knocking out your power? Victor Petrenko,
an engineering professor at Dartmouth College, has developed
de-icing technology that could save power lines from ice
storms.

Until now, the only answer to frozen lines has been to hope
that they don’t break or pull down poles under the weight of
the ice. A single ice storm in early December left more than
1.25 million people in Pennsylvania, New England and New York
shivering in the dark after ice storms snapped power lines.

Petrenko’s trick is to increase the electrical resistance in
cables, something engineers usually avoid because it causes
lines to lose energy as heat. Attached to each end of a line,
his device switches the wires inside from a standard parallel
layout to a series circuit. In normal conditions, the cable
works like a standard power line, but flipping the line to
series increases resistance, and the wires generate enough
heat to shed the ice. The process takes 30 seconds to three
minutes and saps less than 1 percent of the electricity
running through the lines. Utility companies could switch the
lines remotely, and Petrenko says swapping in his cables
would cost less than repairing ice damage.

This summer he tested the technology between two transmission
towers near Orenburg, Russia; China is considering the device
to protect its $170-billion investment in expanding its
energy grid. This fall, Petrenko will test a modified version
of the tech on an Audi A8 that he expects will de-ice its
windshield in two to four seconds. Later, he’ll apply the
tech to airplane wings, which could reduce delays and crashes.
“A plane that could shed ice in seconds,” he says, “would be
a much safer way to fly.”