Harvesting Energy From Ambient Moisture

Generating electricity out of thin air is the fantasy for our modern technology dependant world, but still falls squarely in the world of science fiction. However, researchers from the University of Massachusetts Amherst claim that they have found a way to do exactly that, using protein nano-wires to produce tiny amounts of electricity from ambient humidity.

The protein nano-wires in question are harvested from the microbe Geobacter sulfurreducens, to create a 7 µm thick film that is placed between two gold electrodes. One electrode completely covers the back of the film, while the front electrode covers only a tiny portion of the surface area. When the film is exposed ambient moisture, researchers measured 0.4 V – 0.6 V produced continuously for more than two months. The current density was about 17 µA/cm². This is only a fraction of the output of a commercial solar panel, but it can be layered with air gaps in between. The electricity is supposedly produced due to a moisture gradient through the thickness of the film. Harvesting energy using ambient humidity is not new, but the improvement in power density on this study is at least two orders of magnitude larger than that of previous studies.

The researches have named the technology Air-Gen and hope to develop it commercially. As we have seen many times before, promising lab results often don’t translate well into real world products, but this technology is definitely interesting.

We’ll continue to see all sorts of weird and wonderful ways to free up electrons, like using sweat, but we’ll have to wait and see what sticks.

Thanks for the tip [William Polo]!

24 thoughts on “Harvesting Energy From Ambient Moisture

  1. You have to wonder the state of scientific publishing when even Nature lets through a spelling error in the very first paragraph. But I digress…

    The authors make a convincing case that is isn’t something other than humidity gradient: they remove oxygen, remove nitrogen, check for protein decomposition, vary humidity, do long-term runs, etc. They really are presenting this with the expectation that it’s radical and will be challenged. They acknowledge they really don’t understand the mechanism but postulate some.

    But it seriously doesn’t pass the sniff test. They claim (and show) that simply exposing the device to humid air produces power: NOT exposing it to a humidity gradient. They claim the gradient is produced inside the device. There is no way a gradient can be maintained indefinitely against a flux (of ions, electrons, reagents, whatever), without some consumable that will ultimately need to be replaced. Otherwise it’s a perpetual motion machine.

    Sounds like Pons & Fleischman all over again.

    1. I would expect that it will require fresh moving air all the time to maintain said gradient…ie fluctuating humidity levels. If held at one level for long enough it probably ceases functioning. I also imagine that long term there is some form of corrosion(I know…gold) going on. The current density is very tiny, although stackable.

    2. Call me cynical but doesn’t this break all kinds of laws of thermodynamics if there is no gradient? ‘Ambient’?. If it’s creating its own gradient then that also needs energy input. If they are only measuring micro-amps, is there a chance there is some kind of stray field coming in from somewhere else. The ‘gods of the copybook headings’ probably have something to say about it. Lots of gimmicky and click-baitey stuff in Nature these days, its going down the pan.

  2. As someone from Western Mass, I just want to take this opportunity to let everyone know that the “H” in “Amherst” is silent. Same thing goes for Amherst College.

    There is an Amherst, NY that does pronounce it the other way, but whatever. ¯\_(ツ)_/¯

    Thank you for reading this Very Important Message.

  3. From a perspective of very basic thermodynamics, it seems that if the bacteria are producing the power, they’ll need to be FED to sustain their output. How can this be anything other than a novel bioreactor design, turning fuel into electricity?

  4. Gold? Now the meth heads have new target. Any captured ambient moisture, tends to dissipate fairly quickly. This product, is going to have very short time slot to produce a minuscule amount of power.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.