A View from Kevin Bullis
Generating Power from Electricity in the Air
A researcher describes a potential new source of renewable energy.
Lightning is a powerful manifestation of the electrical charge that can accumulate in the atmosphere. New research, presented at the ACS meeting in Boston on Wednesday, suggests that it might be possible to harness that electrical charge.
Fernando Galembeck, of the University of Campinas in Brazil, has shown that water vapor in humid air can accumulate charge and transfer it to materials it comes in contact with. He says it might be possible to design collectors that exploit this behavior to generate electricity. The technology, which he calls “hygroelectricity” could provide an alternative to solar power in places without much sunlight but with a lot of humidity. It could also be used to prevent lightning strikes, he says, by draining electrical charge out of the air. He notes, however, that the research is very early stage and that such technology could be a long time coming.
Here’s the abstract from his paper:
Many experimental reports associate water-air interfaces with electrostatic phenomena, from “steam electricity” recorded in the 19th century and Kelvin water drop condenser to the close association between heavy clouds and thunderstorms. However, accepted physical-chemical mechanisms for charge build-up and dissipation at water-air interfaces are still lacking. This report shows that: 1) water vapor adsorption on dielectrics or isolated metal surfaces enclosed within a shielded and grounded environment causes charge accumulation on the solid, depending on the relative humidity (RH), nature of the substrate and exposure time. 2) A steep charge increase is observed in liquid and solid insulators under the action of external fields when RH approaches 100%. These results are in agreement with the hypothesis of water acquiring charge during adsorption and condensation, due to partition of aqueous ions.
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