A Swiss startup is testing a low cost green battery that can be recharged with a paper coffee filter and a cheap solution made from fertiliser. The aqueous battery technology can be used in the developing world to replace kerosene lamps.
HiLyte is a startup founded by two graduates of the School of Engineering (STI) at EPFL in Lausanne, has developed a clean, affordable battery using iron, water, coffee filters and carbon felt. A single charge can power an LED bulb for five hours or charge a cell phone. Once used, the liquid from the battery can be safely released into the environment.
Twelve prototypes have been built and distributed in Tanzania and are currently being tested in families.
To generate power, the four-compartment green battery is filled with sheets of iron foil, coffee-filter paper and carbon felt. The user then pours a solution of water and iron sulfate powder which is used as a fertilisera. As the liquid soaks into the carbon filter, it slowly dissolves the iron foil. This releases electrons, generating electricity that is available via a built-in USB port.
The reaction produces iron 2 sulfate, a harmless liquid that can also be used as fertilizer.
The $12 (€11) battery costs around half as much as a kerosene lamp, whiles the consumables cost just 12 cents per recharge. “Once recharged, the battery produces five hours’ worth of electricity,” said Barthes.
“Our technology has the potential to change people’s everyday lives,” said Briac Barthes, a co-founder of the company. “For one of the pilot families, the battery allowed their daughter to study in the evening. Having light can also transform the way people interact, bringing socialization opportunities for isolated and vulnerable families.”
Kerosene is an expensive and highly flammable fuel that emits harmful soot particles when burned in a lamp and are widely used in rural areas of Tanzania.