Static electricity can remove frost from windows using little energy

Static electricity can remove up to three-quarters of frost from a surface, which could save vast amounts of energy and millions of tonnes of antifreeze currently used to defrost vehicles.

In 2021, Jonathan Boreyko at Virginia Tech and his colleagues serendipitously discovered that frost becomes naturally charged as it forms. They used this natural electric field to charge a nearby film of water that could then, in turn, pluck ice crystals from the frost, acting as a natural de-icer. This effect, however, was minuscule and had little effect on the frost overall.

Now, Boreyko and his team have developed a more effective defrosting system by using an extremely high-voltage copper electrode suspended above frost-covered glass and copper. This system can remove half the frost from a surface in around 10 to 15 minutes, and 75 per cent of frost if the surface is also highly water-repellent. “Instead of taking advantage of frost’s pre-existing voltage, we’re trying to turbo-boost the whole effect by applying our own voltage,” says Boreyko.

Removing 50 per cent of frost from a surface using their method required an electrode charged to 550 volts, more than double the voltage supplied by mains electricity in most countries. Unlike electrical sockets, though, the electrode has a vanishingly small current, making it relatively safe. Accidentally touching the electrode would generate an electric shock comparable to an electric fence used on farms, says Boreyko.

This small current also ensures it requires little energy, less than half the energy it would take to heat the frost directly, according to Boreyko.

As well as potentially being used in car windows and on roads, a fast and efficient defrosting method could also be helpful in the aviation industry, which uses vast quantities of antifreeze to ensure aeroplane wings are free of ice that might affect flying performance.

“Instead of dousing hundreds of litres of antifreeze over an airplane wing to de-ice it when it’s taxiing, instead you just have this machine that can drive around airport runways with an electric wand and, as you wave the high-voltage wand over the wing, it just pulls all of that ice and snow right off,” says Boreyko.