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.

    • Tar_Alcaran
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      5 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.world
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        145 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
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        5 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
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      125 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.