Stories
Slash Boxes
Comments

SoylentNews is people

posted by martyb on Wednesday July 31 2019, @04:17PM   Printer-friendly
from the seawater-is-more-than-just-salty-water dept.

There are many ways to generate electricity—batteries, solar panels, wind turbines, and hydroelectric dams, to name a few examples... and now, there's rust.

New research conducted by scientists at Caltech and Northwestern University shows that thin films of rust—iron oxide—can generate electricity when saltwater flows over them. These films represent an entirely new way of generating electricity and could be used to develop new forms of sustainable power production.

Interactions between metal compounds and saltwater often generate electricity, but this is usually the result of a chemical reaction in which one or more compounds are converted to new compounds. Reactions like these are what is at work inside batteries.

In contrast, the phenomenon discovered by Tom Miller, Caltech professor of chemistry, and Franz Geiger, Dow Professor of Chemistry at Northwestern, does not involve chemical reactions, but rather converts the kinetic energy of flowing saltwater into electricity.

https://phys.org/news/2019-07-ultra-thin-layers-rust-electricity.html

More information: Mavis D. Boamah et al. Energy conversion via metal nanolayers, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1906601116


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 0) by Anonymous Coward on Wednesday July 31 2019, @05:22PM (8 children)

    by Anonymous Coward on Wednesday July 31 2019, @05:22PM (#873624)

    Go right ahead. Spend more electricity and resources and cause more pollution making the device than would be generated by this generator. It is quite perverse.

  • (Score: 0) by Anonymous Coward on Wednesday July 31 2019, @09:53PM (7 children)

    by Anonymous Coward on Wednesday July 31 2019, @09:53PM (#873738)

    that’s the beauty of it, it is not all that hard to modify existing things that move in the ocean so they make electricity.
    Example 1) a ship
    Example 2) tide moving past a bridge pylon

    • (Score: 2) by c0lo on Wednesday July 31 2019, @11:21PM (6 children)

      by c0lo (156) Subscriber Badge on Wednesday July 31 2019, @11:21PM (#873778) Journal

      Example 1 is dumb, since you are using energy to make the ship move through the water. (Car analogy - you won't be better in terms of mileage if you'd try to 'recover' some energy using a wind turbine on top of your car)
      May have a point if you consider salt-water from the spray flowing back into the ocean, but I doubt it will generate enough worth increasing the ship's weight by the whole setup; you'd be better with a superhydrophobic coating to shed the extra water faster. So... nah.

      Example 2 might work.

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
      • (Score: 2) by deimtee on Thursday August 01 2019, @11:09AM (5 children)

        by deimtee (3272) on Thursday August 01 2019, @11:09AM (#873950) Journal

        Example 1 is not necessarily dumb. It depends on how much drag is increased by leeching power. Boats generally use an obscene amount of power to push them through the water, and most of that is simply lost. If you can recover 30% of that and feed it back into an electric motor you might be able to significantly improve your fuel economy.

        --
        If you cough while drinking cheap red wine it really cleans out your sinuses.
        • (Score: 0) by Anonymous Coward on Thursday August 01 2019, @10:41PM (2 children)

          by Anonymous Coward on Thursday August 01 2019, @10:41PM (#874330)

          i am guessing that a non working stainless steel plate and a rusty steel plate have total different friction.
          i'll even wager a bet that a rusty plate system that is producing energy has even MEOR friction.
          what would be interesting is if electricity is supply TOO the rusty plates if the friction would decrease?
          maybe this will get you nuclear energized RUSTY submarine hulls ^_^

          • (Score: 2) by deimtee on Friday August 02 2019, @04:21AM (1 child)

            by deimtee (3272) on Friday August 02 2019, @04:21AM (#874476) Journal

            i am guessing that a non working stainless steel plate and a rusty steel plate have total different friction.

            Totally agree, but if you've ever been a boat owner or watched when they refuel you can see just how much energy they use pushing through the water. There is a huge stream of energy going from the fuel tank to dissipated in the water. Can this rusty iron catch more of it than it costs? I don't know, but it's worth checking out.

            --
            If you cough while drinking cheap red wine it really cleans out your sinuses.
        • (Score: 2) by Immerman on Tuesday August 06 2019, @02:47AM (1 child)

          by Immerman (3985) on Tuesday August 06 2019, @02:47AM (#876294)

          It's not *entirely* impossible = in a chaotic open system there's always a chance to "cheat" against thermodynamics, but that's really not the way to bet. As a pretty solid rule if you're generating P kW of electrical or mechanical power as a result of your motion, you're also adding at *least* PkW of additional drag, and probably much more. Second law of thermodynamics: you *always* lose.

          Consider - if that wasn't the case then you could make a free-energy device by lining an ultra-low-drag ring of pipe with this power generating material, and generate more power than required to keep the water moving.

          Now, it might be a viable alternative to driving a dynamo to produce electricity for other ship systems... But given that it would involve exposing a delicate ultrathin skin to the abuse normally seen by a ships hull... I'm going to bet against it.

          As a powerstation though - if you could suspend generating plates in big watersacks filled with a sterile saline solution, the agitation from the surrounding water might provide nearly the same energy without exposing the delicate surface to an uncontrolled environment

          • (Score: 2) by deimtee on Saturday August 10 2019, @07:16AM

            by deimtee (3272) on Saturday August 10 2019, @07:16AM (#878138) Journal

            I didn't say it was likely, just that it was worth checking out. :)
            There is a (very) small possibility that leeching energy from the water would reduce micro-turbulance and increase laminar flow, actually reducing drag as well as generating energy. Do I think it likely? No, but it doesn't violate any laws of physics and the benefits would be large enough to definitely make checking it out worthwhile.
             

            --
            If you cough while drinking cheap red wine it really cleans out your sinuses.