Brazilian scientists believe they have found a way of tapping electricity direct from the air - and preventing lightning strikes at the same time.
"Our research could pave the way for turning electricity from the atmosphere into an alternative energy source for the future," said study leader Dr Fernando Galembeck of the University of Campinas. "Just as solar energy could free some households from paying electric bills, this promising new energy source could have a similar effect."
Scientists have been unsure about whether an electrical charge is created when water vapor collects on microscopic particles of dust and other material in the air.
Galembeck and his colleagues have simulated this using tiny particles of silica and aluminum phosphate, both common airborne substances, and shown that silica became more negatively charged in the presence of high humidity and aluminum phosphate became more positively charged.
"This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes into contact with," Galembeck explained. "We are calling this 'hygroelectricity', meaning 'humidity electricity'."
In the future, he says, it may be possible to develop collectors, similar to solar cells, to capture hygroelectricity and route it to homes and businesses.
Just as solar cells work best in sunny areas of the world, hygroelectrical panels would work more efficiently in areas with high humidity, such as the northeastern and southeastern United States and the humid tropics.
Galembeck said that the approach might even prevent lightning from forming and striking. He envisions placing hygroelectrical panels on top of buildings in regions that experience frequent thunderstorms. The panels would drain electricity out of the air, and prevent the buildup of electrical charge that is released in lightning.
His research group is now testing metals to identify those with the greatest potential for use in capturing atmospheric electricity and preventing lightning strikes.