Introduction: Soil Battery
Two different metals, usually copper and zinc, and inserted into the soil, the use of the electrolyte in the soil constitutes a primary battery. Two metal pole will produce about one volt potential difference.
Dutch designer Marieke is this simple principle design of several small works by a force of nature, have a look!
First, is this light, dozens of copper and zinc electrodes inserted in the soil constitutes its energy, as long as you keep watering, LED bulbs will illuminate you.