With all the fossil energy hunger in 2022, In this project I want to use only the energy what earth and soil us freely gives. It may be negligible but you can easily harvest and use it.
Can I use an earth battery to power low-power devices? Yes, I did it. I made a simple battery with soil, coppertube and a zincplate. The cell voltage is 0.9V and a short circuit makes 200 microAmp. The pendulum consumes about 40 microAmp. A supercap of 10F is the buffering battery. Duration tests have still to be done. Also soilcell improvement is part of the project. I love low-tech minimalism.
My Non-Stop Solar Devices are running for month’s and some for years. More at YouTube.