Sam Goldman knows what it means to live in the dark. For four years, the young Peace Corps volunteer inhabited a remote rural community in the West African country of Benin. Kerosene lamps were the primary light source in this off-grid village. One night in 2003, a snake came out of the shadows and bit him. He rode 7 kilometers on the back of a motorcycle through the murky darkness to locate anti-venom. Luckily, another village had one dose left in a kerosene-fueled refrigerator. Not long after this harrowing evening, his neighbor—a 12-year-old boy—endured serious injury from a kerosene lamp accident.

“I had a series of things happen in a relatively short amount of time, which got me thinking,” Goldman says of the perils of off-grid living. “It seemed like a huge market failure. You have millions of people who want something better and are willing to pay for it, but nobody [is] serving them.”

In fact, it's a market of 1.6 billion individuals. That's how many people live without electricity, according to the World Bank, meaning nearly a quarter of the world's population effectively shuts down with the sun. Studying and socializing are limited to the paltry light cast by candles or kerosene lamps. In addition to the constraints on activities and work, the danger of fuel-based lighting is well documented. According to the World Bank, kerosene lamps guzzle 77 billion liters of fuel, emit noxious smoke and CO2, and cause dangerous fires and personal injury. Then there is the cost. In sub-Saharan Africa, where 560 million live without electricity, families spend as much as a third of their income on kerosene.

Today, Goldman is the CEO and director of South Korea–based D.light, a three-year-old for-profit company on a mission to bring safe, affordable solar lighting to off-grid families. Last year the company released the Kiran, billed as the world's most affordable solar lantern (it retails for $10 to $15 depending on the country). The lamp is composed of a 0.3W integrated solar panel and high-powered LEDs. It is marketed as a replacement for kerosene. There are two task settings: high for studying and reading, and low for walking. Its tempered plastic body is transparent, creating 360-degree illumination when hung and eliminating the shadow cast by traditional lantern designs. With eight hours in the sun, the Kiran collects enough power to provide eight hours of low light or four hours of bright light. The lantern can withstand the high winds and temperatures of climates like those in Africa and India and it can endure extensive daily use for five to 10 years, according to Goldman. “The environment is pretty intense compared to the way someone would use something if they were going camping,” Goldman says. “People need these products. They use them daily.”

“It's all about the consumer,” says Robin Chilton, head of product design with D.light. “In designing the Kiran, we spent a lot of research time living with consumers, understanding their needs, and trialing prototypes with them.”

REACHING AN OFF-GRID POPULATION Understanding and cultivating this global consumer has become a priority for many nonprofits, nongovernmental organizations, and social entrepreneurs as they begin to realize the potent impact that off-grid lighting systems could have. In addition to the significant ecological benefits of moving from fossil fuel to renewable energy, there is also a market base hungry for affordable and reliable alternatives.

Itotia Njagi is the program manager with Lighting Africa, a World Bank initiative aimed at helping the lighting industry connect with consumers in developing nations. He says a cadre of new social entrepreneurs, like D.light, are looking to pioneer the field of off-grid lighting and develop the distribution infrastructure to get these fixtures and the equipment to underserved users. “This is an interesting market where social entrepreneurs are seeing an opportunity and spending the time to understand the needs of the market.”

Laura Stachel, co-founder and director of San Francisco's We Care Solar, is one of those social entrepreneurs. She is not a lighting designer by profession and—as with Goldman—it was a challenging problem in the field that led her to develop an off-grid lighting solution. “I am an ob-gyn and I was trying to do research about maternal mortality in Africa,” Stachel says. She discovered that sporadic electricity was a major issue. Most hospitals and clinics have anemic energy sources and are limited to just a few hours of electric light. One evening, the lights went out while Stachel was watching another doctor perform a casarean section in a Nigerian hospital. The doctor was forced to finish the procedure by flashlight. “I felt there was nothing we could offer that hospital if they couldn't get access to light,” she says.

Back home in San Francisco, Stachel partnered with her husband, Hal Aronson, a solar energy educator and designer, to develop a solar lighting system for the hospital. Statchel asked her husband to create a demo of the lighting that she could pack in her suitcase and easily bring through customs. The hospital staff in Nigeria was so taken with the demonstration, they begged Statchel to let them keep it. From this, the Solar Suitcase was born. Weighing about 35 pounds, the suitcase contains all of the components necessary to power two overhead LEDs as well as charge walkie-talkies and cell phones. It also includes LED headlamps that come with rechargeable batteries. Since its introduction in June 2009, the Solar Suitcase has been sent to nine countries from Tanzania to Rwanda, to Tibet, Mexico, and Nicaragua. In Haiti, medical relief teams and maternity clinics now use them. The cost of the system is about $1,000 and Stachel works with nonprofits and others to raise funds to offset the cost to the user.

Recent years have seen a rise in the development of these off-grid lighting systems that capitalize on compact fluorescent and LED technologies. They get their fuel from alternative energy sources such as wind, water, and human power, such as hand-cranking and bicycle pedaling. But it is solar that is encouraging the most research and development. “We use solar energy because it is the most versatile,” explains Michael Fark, executive director of the non-profit foundation Light Up the World (LUTW). LUTW is an international humanitarian organization that has worked in over 50 countries to provide efficient lighting systems to disenfranchised communities.