Nokero, a Hong Kong-based company, has debuted the world's first solar-powered LED lightbulb. Costing $15, the Nokero N100 has kerosene lamps in its sights but, at $15 a pop (although that drops to $10 if you buy 48 or more) it's going to be an expensive alternative for people in the developing world and for aid agencies in disaster zones. Anyone with a patio or a camping habit, however, might find it more than useful.
The rainproof bulb is made from impact-resistant plastic, with four solar-panels on the side, and a replaceable battery. Fully charged, it can give around four hours' worth of light, although a single charge will probably only give users around half of that. It consumes just 1/200 of the energy of a typical kerosene lamp and provides five times as much light. Over 190 million tons of CO2 are released each year from fossil fuel-burning lamps. That's the equivalent of 30 million cars, or 2 million less than are currently on the U.K.'s roads, if you want to put it into perspective.