Power defrost

Working with his colleagues at Ice Engineering in Lebanon, New Hampshire, Dartmouth College engineering professor Victor Petrenko has invented a way to keep ice off power lines.

The technology is called a variable-resistance cable (VRC) de-icing system.

With only minor cable modifications plus some off-the-shelf electronics, the system switches the electrical resistance of a standard power line from low to high.

The high resistance automatically creates heat to melt ice build-up or keep it from forming in the first place.

'The beauty of the VRC system is that it's fully customisable and is an affordable addition to the current manufacturing and installation process,' said Gabriel Martinez, Ice Engineering's vice-president, who studied under Professor Petrenko at Dartmouth.

'And it works without causing any service interruption whatsoever,' he added.

Ice Engineering plans to install and test a full-scale VRC system prototype on a section of power line in Orenburg, Russia, later this month.

The company is also currently negotiating full-scale installations of VRC in other regions of Russia and in China.

Martinez said the changes in manufacturing and installation required to implement the VRC system would result in a less than 10 per cent increase in overall cost.

Since utility companies normally replace three per cent of their cables every year, the system could be installed as part of the regularly scheduled maintenance process.

Furthermore, the life span of the de-icing system would match or exceed the life-span of the utility cable, approximately 30–50 years.

The system would pay for itself by practically eliminating the cost of fixing downed cables and power outages due to ice and snow, according to Martinez.

Another benefit of the VRC system is that utility companies using the system would have full control over its functionality, said Martinez.

Time, temperature, and location can all be adjusted manually or set and controlled automatically with electronic sensors.