Lack of access to low-cost electricity is perhaps one of the biggest challenges faced by rural African villagers. It is a problem that hasn’t escaped the development community — from multilateral and bilateral donors funding the construction of more power plants across the continent to social entrepreneurs who have introduced innovative products that make use of solar and wind power, both readily available in Africa.
But there’s something else that can be used to power rural villagers across the continent: soil. That’s according to Lebone, a social enterprise that has developed a microbial fuel cell, or MFC, which taps energy in the soil to create enough electricity to power LED lights and charge mobile phones.
“You can just literally make energy from dirt,” Aviva Presser, one of Lebone’s founders, has noted. “And there’s a lot of dirt in Africa.”
Presser and the rest of Lebone’s founders were classmates at Harvard University in the United States; most of them trace their roots back to African soil. The company’s name, in fact, means light or lamp in Northern Sotho, one of South Africa’s official languages.
How exactly does MFC “make energy from dirt,” as Presser suggested? Some microorganisms in ordinary soil are capable of producing small amounts of energy as they break down organic material such as dried grass, dead leaves or compost, Lebone says. The MFC harnesses this energy and converts it to electricity that rural households can use for their basic lighting needs, among other simple applications.
The initial Lebone battery was a simple device made of manure, buckets, copper wires and graphite cloth. Refined prototypes still make use of other readily available and low-cost materials: sand, mud, salt water, chicken wire, and a five-pound bucket with a graphite-cloth anode.
The device is buried in the soil and connected to a circuit board that can then be used to charge a battery. Each cell costs less than $15 to assemble and can last up to 12 months if regularly watered to keep the metabolic reaction going.
Lebone, like most startups, is continually improving its invention. It is partnering with design teams to better meet the needs of its intended end users. The company, which was founded in 2008, has won grants from the World Bank, among other public and private supporters, to field test the MFC in Namibia and Tanzania.
Where does “dirt power,” as Lebone describes it, rank among clean energy solutions such as wind and solar? The jury’s still out. But, it is a reminder of grassroots power.