In the poorest parts of the world, especially in rural villages and outlying city slums, people are confined to their homes by darkness at night. The only light they have usually comes from a smoky fire or an air-polluting kerosene lantern. But an entrepreneur from Houston, Texas is trying to change that by distributing flashlights powered by energy from the sun in developing nations. VOA's Greg Flakus has more in this report from Houston.

The flashlight venture began several years ago in Africa where former U.S. diplomat Mark Bent was working for an oil company. He saw that people in many poor rural villages were trapped by the darkness of night, unable to read, to work or to venture out too far from their homes, unsure of who or what might be out there.

"The social interaction stops in Africa when the sun goes down," said Mark Bent. "You don't walk around, you do not study, you stay home."

Mark Bent's solution is a flashlight that has a solar panel on one side of its shaft to capture energy from the sun.

"This is a photovoltaic panel, a solar panel, it is a poly-silicone panel, and it produces electricity when hit by sunlight," he said. "The electricity is then stored inside the light in three double A batteries, rechargeable batteries, then at night that energy, which has been stored, is released to the light-emitting diodes and they provide lighting."

Light- emitting diodes, sometimes called L.E.D.s, provide sufficient light to read or find a trail in the dark, but they do not produce much heat nor do they produce eye-irritating glare. As recently as a few years ago L.E.D.'s would have been too expensive for such a device, but innovations and production efficiencies have now made them affordable.

Mark Bent says one of the big benefits of using this kind of flashlight is the reduction in use of wood fires and kerosene lanterns, which produce noxious fumes and greenhouse gases.

"One kerosene lantern puts out 100 kilograms of carbon gas, annually," said Bent. "Okay, that is not that much, but when you consider that one third of the planet, two billion people, rely on kerosene for their lighting, illumination needs at night, that is an amazing amount of carbon."

With financial backing from Exxon Mobil and a few other corporate donors, Bent has introduced his flashlight all over Africa and in other parts of the world as well. He is also encouraging Americans to buy them through a special plan that also benefits other nations.

"I realized I could sell this same light in the United States, which will allow people in the United States to have a more sustainable and environmentally friendly flashlight," he said. "So I worked out a program called BOGO, buy one, give one. An American can buy my light for 25 dollars. I will ship it to their home from my warehouse here in Houston and with that same amount of money, no more, I will deliver a second light to the developing world."

Bent's company, Sunnight Solar, is now looking at other applications for solar energy in poor areas of the world. One device would use solar panels to power a water purification system that uses ultraviolet light to kill organisms; another would use natural insecticides like chemical from chrysanthemum flowers to combat malaria-causing mosquitoes.

"All these things are very low energy, have very low energy requirements, and are all doable, but no one has really looked at it in that way before," said Mark Bent.

Mark Bent is full of ideas, but his main focus for the moment is helping poor people everywhere escape the darkness of night, using the power of the sun.

rechargeable battery:充电电池

kerosene lantern:煤油灯