Harnessing Dirt for Electicity

An innovative way to generate power off the grid

Originally posted on June 16, 2010

It is called “Dirt Power.” Or, more specifically, as the scientists call it, a microbial fuel cell. A team of undergraduate researchers at Harvard, a small liberal-arts university in New England, invented a battery that runs on dirt. Actually, it runs on microbes that like to hang out and dine on the decaying organic matter that exists in the dirt. The team that invented this technology – an organization called Lebone – won the MIT IDEAS competition and, recently, their creation was called one of the 10 most brilliant inventions of 2009 by Popular Mechanics. First, the problem:

There is currently a dramatic shortage of electrical power in Africa. One billion Africans, constituting a sixth of the world’s population, generate only 4% of global electricity. In most African countries, 95% of the population is living off-grid with no access to electricity (World Bank Millennium Goals Report, 2006). This has a devastating effect on socio-economic development, education, health, and safety. Imagine a village at night in which students are walking to distant highways to study under streetlights, where small merchants are investing half of their resources to pay for kerosene lighting to run their operations, and where emergency health workers, if operating at all, are trying to stitch up wounds and perform surgeries by candlelight. Lack of energy is one of the Africa’s biggest obstacles to development, and a major deterrent for foreign investors.

We believe that providing cheap and consistent lighting in rural households and health centers in Africa is a key leverage point that will overcome this root obstacle to development. With appropriate lighting and energy technology in target villages, the performance of village students will increase, the health of rural populations will improve, the incomes of local households will grow, and villagers will be energized to become more self-reliant and productive overall.

And, the solution:

The results of the Development Marketplace competition was presented at the ‘Lighting Africa 2008? conference that took place in Ghana’s capital city Accra between May 5 – 8. So how does this technology work? According to Hugo Van Vuuren, one of the students in the winning group, “a microbial fuel cell taps into the energy that soil microbes generate when they break down organic matter. Literally, this is energy from dirt: no special microbes or conditions are needed other than enough moisture for the bugs to do their work. Essentially all you do is dig a hole, layer an anode, some soil, sand and a cathode – and connect the anode and cathode to a circuit board to charge a battery that can power an LED (light emitting diode) light, run a radio or charge a mobile phone.”

My emphasis in bold. The key to bringing electricity to the billions of people without access comes from…dirt. Pretty cool stuff!