> generated 68x more power than needed to operate its sensors

> all components...can be purchased at a local hardware store

I can't help but think this would be used for surveillance. All you need is dirt to run a sensor and transmitter. But it's cool science.

It would be interesting to figure out how much does it take away from the soil biome's energy budget. If you did a whole acre of these, would the insects, worms, and millipedes take a hit, and then birds and reptiles etc.?