The world's first solar-powered lightbulb could provide an alternative to fossil-fuel lighting in the developing world, according to its makers.
The Nokero N100 is about the size of a standard incandescent bulb and can be charged during the day to provide light at night. It comes with a replaceable, rechargeable battery so it can be renewed to run for several years.
When fully charged, it can give four hours of light - less on a cloudy day or in northern countries. Its makers envisage it replacing kerosene lamps in developing countries and after disasters.
"We’ve done everything we can to make this solar bulb affordable and long-lasting so the people who need it can afford it, and reap the benefits, " said Nokero’s inventor and founder Stephen Katsaros.
“There are so many ways this product can change lives: It can help keep families and shopkeepers safe, help students study at night, eradicate indoor pollution, and reduce worldwide carbon emissions.”
As many as 1.6 billion people worldwide - a quarter of the world's population - still lack access to electricity, the company says, with another million having only limited access.
People using fuel lamps spend five percent of their income on fuel, according to UN figures, and Nokero says the bulb can pay for itself within months when replacing a kerosene lantern.
The N100 is made of impact resistant plastic, and is rainproof, says the company. It has four solar panels, and five bright LEDs. The replaceable nickel metal hydride battery lasts up to two years.
"There’s no other product like this on the market," Katsaros said. "This bulb represents our best chance at eradicating an outdated, dangerous practice and replacing it with a safe, sustainable solution."
A single bulb costs $15, but there are big discounts when ordering in bulk.