Power from the Soil Beneath Our Feet

There are numerous examples of home-made soil batteries on the web. All you need they say is an old soda can, copper wire, a piece of aluminum, and moist soil. We’ll show you a video of that in a moment. But first we have more important news to share. EuroNewsGreen reports we could store solar power from the soil beneath our feet someday too. Just fancy that!

Harnessing Microbial Power from the Soil

Scientists at Cardiff University in Wales, United Kingdom are chasing the idea down. “The possible scale of that impact is really exciting,” their lead researcher Michael Harbottle says. “To see something that’s really quite novel, possibly having a big impact is what’s driving us.”

The prof’s thinking is still in the realm of possibilities, abstract science if you like. But if a kid could make an LED brighten using soil, why not the lights of England too? Right now Harbottle is exploring the idea of harnessing solar power to feed the process, and it could work like this:

Electrical energy is food to micro-organisms because it helps them survive.
They use it to electro-synthesize carbon-based molecules from carbon dioxide.
They then convert these molecules to more complex ones we call acetate.

Here’s an Experiment to Show You How

Acetate, Harbottle explains ‘is the same sort of molecule found in vinegar, minus the acid’. It acts as a chemical store of energy, like our old friend the lemon battery we imagine. So far so good, but how do we tap this power from the soil?

Tapping Energy Using a Microbial Fuel Cell

We’re getting a little out of our depth here. However, we do understand microbial fuel cells are a bio-electrochemical process. And that this produces electricity using electrons derived from biochemical reactions.

Switching on the microbial fuel cell would therefore activate a different set of bacteria in the soil. These would feast on the acetate, releasing electrons to flow through electrical circuits.

“One advantage of the idea is it doesn’t require resource-limited, or hazardous chemicals like lithium that are used in other battery technologies,” Harbottle explains. “It creates organic molecules that are often present in the soil anyway. And these are produced naturally by microorganisms in smaller quantities.” So we could say this is a truly organic battery.