It's Not the Heat, It's the Humidity: Electricity From Air

By Eric Wolff | August 30, 2010 4:00 am

Who needs Mr. Fusion if you can draw energy straight out of the air? A team of scientists from the University of Campinas in Brazil worked out a way to draw charge from  air in high humidity, going some distance to explaining the origins of lightning, and offering the promise  of renewable power for San Francisco and New England, where humidity is abundant and sunshine, not so much.

The study authors, Telma R. D. Ducati, Luis H. Simoes and Fernando Galembeck, found that tubes of aluminum, stainless steel, or chromium acquired electric charge in high relative humidity, and that the charge rose as the humidity went up.


Those metals are key, because none of them rust in swampy air, the paper said. Instead they develop a metal oxide coating that absorbs ions from surrounding water droplets. Whether the ion is OH- or H+, the other half of the water molecule ricochets off into the atmosphere, allowing the metal tube to acquire a charge.

I’m rather taken with the simplicity of Ducati et. al.’s experiment: They made a sandwich of several sheets of filter paper, a sheet of aluminum and a sheet of stainless steel. They mounted this capacitor in an aluminum box, and then put the box in a Faraday Cage. They could easily generate a charge simply by adding humidity to the space in the box, and drain it with a short circuit.

Whether this is the first step to a new kind of renewable power will take a long time to figure out, but it seems to offer a new opportunity to humid parts of the country that can’t easily benefit from wind or solar power. The scientists have decided to call it hygroelectricity, which means “humid electricity.”

I recommend the paper itself to anyone with even a modest recall of high school chemistry, or a semester of college chemistry. In most respects it’s a model of clarity not often seen in published scientific studies.

MORE ABOUT: hygroelectricity

Comments (8)

  1. Georg

    this is something appropriate for 1st of April!
    The blog (!) cited speaks of aluminium phosphate
    and silica “common” in atmosphere, which I
    doubt, and the use of a Faraday cage is typical
    for electrostatic experiments, as
    the micŕoscopic amount of charge is only collected
    There is no explanation of how to drain current
    from the gadget.
    Maybe this things play a role in genesis of lightnings,
    but as a source of electric power it is nonsense.
    I’d like to read the original, because I think this is at
    least partly produced by a consecution of erronous

  2. MT-LA

    @Georg: “I’d like to read the original, because I think this is at
    least partly produced by a consecution of erronous “reportings”.”
    So, why dont you read the original? The link to the actual study is available in the second paragraph. And no, it’s not a blog(!). Or perhaps you prefer to make assumptions and then spout off as if you’re some kind of expert on the matter.
    Considering the paper is on the American Chemical Society’s website (ACS), I’m willing to believe that the authors have some basis in reality. Furthermore, from what I remember about physics, if you can create a voltage difference between two conductors, then you have a means of generating electricity. The amount of electricity generated is then a matter of efficiency and scale.

  3. melyndaphilpott

    Maybe the fact that we feel ‘drained’ when in the midst of an extreme humidity wave could go some way to helping us understand how to drain current from a charge collector. I know that I can’t go across a Wal-mart parking lot in Arkansas during the summer without having to a) take a shower (sweat the current out maybe?) and b) needing a nap.

  4. Georg

    Hello MT-La.This is what I mean:
    a blog referring to the same original. There is the ominous
    phosphate and silica.
    Meanwhile I found the original paper and started to to study it.
    Still I am wondering, wheter they violate first LOT or not.
    The charges seem to be very small, it is not easy to rule out
    chemical action (= dissolution) of the metal sheets.

  5. kgwceyzelpvbosirmstk, delo, KqJnFJT.

  6. Funds 1 automobile loan terms include 30, 60 and seventy two months. Capital One particular, in contrast to other corporations I have carried out small business with is completely rigid with regards to adjusting there charges. Even when the enormous costs are resulting from all of your tiny hidden fees they have. Capital 1 Monetary can also be involved with instalment lending, healthcare financing, and little business lending activities.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


See More

Collapse bottom bar