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.
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.
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.
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.