People in developing countries may soon have a cleaner, safer way to light their homes for only $5 a unit.
GravityLight is a prototype that has been in the works for four years. It works by attaching a bag full of about 20 pounds of rocks, sand or dirt, to a light. The weight of the bag fuels the inner mechanisms of the light for 30 minutes of power at a time, after which the bag can be reset for another 30 minutes. The energy can be used to softly light a room, to power a reading light, or to charge devices like radios.
Its innovators, Martin Riddiford and Jim Reeves, recently surpassed their funding goal on indiegogo. Their plan is to donate 1000 of the devices to African communities.
A lighting solution like GravityLight could go a long way toward replacing kerosene lamps as the primary source of lighting in developing countries. According to a 2003 study by PhD Evan Mills of the University of California, “Fuel-based lighting (typically kerosene) represents $38 billion per year in fuel costs and 260 MT of carbon-dioxide emissions worldwide.”
A report by the U.S. National Park Systems highlights the human health hazards presented by the burning of kerosene. The report identifies benzene, xylene, napthalenes and toluene as just a few of the harmful chemicals in kerosene which can cause damage to the liver, heart, lungs, kidneys and nervous system. Benzene, in particular, is a known carcinogen associated with crude oil, from which kerosene is derived. Burn injuries also commonly result from the use of kerosene lamps, and kerosene expenses often make up a large percentage of the average household income in rural Asia and Africa.
GravityLight would not require any battery power, eliminating the expense of buying new batteries when they run out, the problem of recharging batteries and the issue of disposing of used batteries. This is notable because it is unlikely that individuals in developing countries would easily be able to recycle used batteries, and their improper disposal can be incredibly harmful to the environment as they release harmful metals and chemicals into the air and water. In the U.S., where battery-recycling facilities are easily accessible, 179,000 tons of battery waste still makes it into landfills.
Critics of GravityLight point out that the device currently emits a relatively low wattage, and that it is unable to charge mobile phones. There has also been some concern about producing the lights so cheaply because villagers in developing countries would be largely unable to replace broken parts or seek out repairs for a broken GravityLight. Nitpickers have even criticized the name of the product, saying that the device is powered more by kinetic energy than gravity, although the point is hotly contested among physics nerds.
Whatever the case, GravityLight may illuminate new strategies for providing clean energy to people across the globe.