This clever little mud-powered LED light was created by Marieke Staps and is named, quite simply, the Soil Lamp. It features mud-filled cells made of copper and zinc, which conduct electricity produced in the wet soil to the LED.

The mud acts as an electrolyte and only needs a little water now and then to keep the process running. Sadly, this is not indefinite. It is not clear how long the chemical reaction will continue to run, but at some point the light will cease to function.

Staps has encased the unit in a glass tube to highlight its simplicity, but would be more practical placed directly in soil – in the garden outside, or even in a pot inside. A lever could be incorporated into the design that can push out the old mud in the tubes once the chemical reaction has ended, ready for you to plunge the unit into a fresh patch of muddy soil to start the process up again.

Don’t know about you, but I can see a real commercial product here. I wonder how much energy it’s able to generate and for how long? I would imagine the Soil Lamp’s life between mud-changes could be considerably lengthened with the addition of an on/off switch, which directs the unused energy to a battery during the daytime when the light wouldn’t be required.

Sources:
Marieke Staps via MAKE