A Northwestern University-led team of researchers has developed a new fuel cell that harvests energy from microbes living in dirt. About the size of a standard paperback book, the completely soil-powered technology could fuel underground sensors used in precision agriculture and green infrastruct

Northwestern University researchers have introduced a soil-microbe-powered fuel cell, significantly outperforming similar technologies and providing a sustainable solution for powering low-energy devices.

  • cmnybo@discuss.tchncs.deEnglish
    562·
    9 months ago

    How much power does it produce? It must be pretty bad since they don’t mention it anywhere in the article.

    • Tar_Alcaran@sh.itjust.worksEnglish
      37·
      9 months ago

      They claim “68 times more than required to operate the sensors”, then mention a sensor to measure soil moisture.

      A basic soil moisture sensor, like say, the ones I have stacked on a shelf here, will work on 2 AA batteries. It runs on 2V at 10mA. So that’s 20 milliWatts, and in willing to be a fair bit of that goes into the electronics that make a red, green or orange led light up at certain moisture levels, and the bit that beeps when below a certain level.

      Still, this sets something of an upper limit at 1.3W, or maybe 680 mA? Those seem rather high, so I’m betting their moisture sensor is a bit more delicate than my model. It depends on the size and number of cells though.

      • muntedcrocodile@lemmy.worldEnglish
        14·
        9 months ago

        Im pretty sure most soil moisture measurment devices just measure the capacitance to measure dielectric permittivity. U can design such a setup to use any arbitrary amount of power depending how close the electrodes are rogether etc etc.

      • Willie@kbin.social
        5·
        9 months ago

        Yeah, I am imagining the soil moisture things from the garden store, with the little needle gauge thing, that takes so little power that there’s no battery slot. I feel like the amount of power this thing makes is extremely low.

    • WHYAREWEALLCAPS@kbin.social
      12·
      9 months ago

      The linked article has a table that gives 1.74 uW/cm^2. However glancing over the rest of the paper there’s a ton of variability of output.

    • Magrath@lemmy.caEnglish
      84·
      9 months ago

      Who debunked this? I don’t any comments debunking it.

      Also if you read the article it has limited applications so it’s not some pie in the sky you think it.

      • linearchaos@lemmy.worldEnglish
        10·
        9 months ago

        I kind of get op’s point. It’s not straight up debunked, but it’s so few microwatts that they can power the sensor but they can’t store log data.

        It requires a close proximity powered base station nearby to fire a signal out to get reflected back somehow.

        I’m having a hard time picturing any viable setup outside of a laboratory experiment. If you’ve got a powered base station within a few inches of it why not just power it with that?

  • TheOneWithTheHair@lemmy.worldEnglish
    241·
    9 months ago

    " As long as there is organic carbon in the soil for the microbes to break down, the fuel cell can potentially last forever.”

    It’s also a stationary battery

    “Although the entire device is buried, the vertical design ensures that the top end is flush with the ground’s surface.”

      • take6056@feddit.nlEnglish
        1·
        9 months ago

        I’d say a battery is at least something that should be “chargeable”, either one time or rechargeable. I dont think you can use solar cells to store energy back into the sun.

        Not saying that my definition does work for the dirt fuel cell, talked about in the article, though.