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benthic_microbial_fuel_cell.jpg

“Benthic microbial fuel cell” is propeller-head code for the following very interesting fact: If you bury a metal plate a few centimeters beneath the ocean floor, and elevate a parallel plate a few centimeters above the ocean floor, the potential between them (due to ongoing microbial metabolism in the sediment) is enough to generate useful power. 800mV is a typical figure, but if I understand correctly, the current is directly related to the area of the plates, so the amount of power available by this method is theoretically only limited by the size of the plates you can install. Mark Nielsen is a doctoral candidate at Oregon State University under Dr. Clare Reimers, an expert in the field. This page at the OSU website provides a nice general overview of the concept and of Mark’s work in particular.

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.


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Comments

  1. Craig says:

    … or more accurately, the flaw in this idea, is that it only works if the water-sediment boundary can be kept between the two plates. If the sediment shifts, then you stop generating power. What’s worse is that, over time, the matter that drifts down from the surface to become fresh sediment, accumulates on top of the top plate, and eventually your generator becomes buried. Oops.

    Evil Overlord Rule # 12: One of my advisors will be an average five-year-old child. Any flaws in my plan that he is able to spot will be corrected before implementation.

    1. ehrichweiss says:

      Craig, did you by chance get that Evil Overlord quote from the now defunct Fringeware mailing list?

    2. The image, of course, is just a cartoon illustrating the concept. The problems you mention, it turns out, are easily overcome:

      http://oregonstate.edu/~nielsema/Marks_Homepage/Home_files/Nielsen_2007.pdf

  2. Gaijintendo says:

    Now all we need to do is get rid of all those unknown species at the sea bed.

  3. cdreid says:

    Mindnumbingly dumb. See evil overlord rule #1 (from How to succeed in evil i think- see podiobooks.com)

    1. Yay lets destroy the ocean floor because we’re not destroying the ocean fast enough.
    2. Im sure alll that microbial action will continue when you shut off its food source by encasing it in metal plates.
    3. Thank god metal doesnt corrode or anything.. in salt water..
    4. Im quite certain superbarges ripping the top off the ocean floor, planting plates then dumping it all back wouldnt affect the microbes, the ocean, the global climate or anything

    Neilson and Cliemer.. Phd’s… seriously?

    1. zof says:

      Seeing as it is designed to power instruments and not cities I fail see a point to your argument of destroying the oceans. As for the food source, it can easily be overcame by many more small plates then 1 large one, as for corrosion its a matter of how long you expect that instrument to work anywho… its not a great idea, but it is a good one and should be given all consideration.

    2. Pascal says:

      Before to start speaking of “evil overlord” you should begin to read completely his paper. His work doesn’t destroy the sea floor or anything else but it’s natural. Maybe you rather use fossil fuel or nuclear. Are you an expert to speak in that way.

      1. hurf durf says:

        Yeah, its natural, unlike oil from long dead plants we drill from the earth, wood from short dead plants we drill from the forest, and nuclear which comes from somewhere out in space (I dunno, it def can’t be found in nature, I’m sure about that).

  4. pmjett says:

    Really, cdreid? I think you’re a little quick to start hating on this idea. I’d say it’s a reasonable bet that none of these researchers envisioned “superbarges” or “destroying the ocean floor.” I suspect that this research is more of a starting point idea (as much PhD research is) Perhaps you can implement this in industrial wastewater ponds. (And yes there’s benthic activity, and I’ve seen 500 acre ponds) Perhaps you can use this a some sort of biological battery system in other manmade settings, where recovering a little extra power is icing on the cake. Who knows?

    Sounds like a cool idea to me.

  5. volkemon says:

    @cdreid- Yeah…little bit of hatin’ there….

    But THANKS for the cool heads-up on podiobooks! And the ‘how to succeed in evil’ title…I listened to the first three podcasts before I could break away.

    Plates in the wastewater ponds…Hm…

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