Smithsonian.com

Photo: Threeboy

Forget wind, solar and even seaweed. Renewable energy is getting down and dirty…with dirt! A Harvard scientist is striving to harness the energy potential found in the mud and muck, soil and sand, and clumps and clods we tread on every day.

The Pacific Standard fills in the dirty details:

How do you make electricity with dirt? First you need some kind of jar, with a piece of graphite or some other non-corrosive metal, at the bottom. Then put in dirt with very little oxygen, and another piece of graphite. Soil microbes are constantly making electrons, but if there’s oxygen about they’ll put the electrons into the oxygen. If there isn’t any oxygen, they’ll dump the electrons on pieces of metal—i.e. the graphite.

Microbes are finicky, though. Figuring out just which bacteria like which dirt and in what quantity will take time. But the research has high hopes for the project and low goals for the cost so that farmers in Africa can fashion a DIY version of the contraption.

Ultimately, she hopes that increasing refinements will reduce the price to $5 or less for those who build the devices out of scraps.

Presser sees the design as part of a wave of appropriate lower-cost high-tech for Africa that can help people live better.

More from Smithsonian.com:

A New Exhibition Gets All the Dirt on Soil 

I Think I’ll Go Eat Dirt