Africa may be about to get a whole lot more power.

For years, nonprofits have worked to make lighting available and affordable to Africans who aren't connected to a power grid. But they've managed to help only a tiny percentage of that population, mainly by selling them inexpensive kerosene lamps.

Now, some of the world's biggest energy companies are thinking on a much grander scale. They're conducting projects to test the viability—and marketability—of solar-powered systems to provide electricity for lighting and other purposes in villages all over Africa.

The companies are aiming to sell the systems to governments and nonprofits, which could use them to provide power to villages at a discount or for no charge. The systems cost less than it would to expand traditional power grids—offering a relatively swift, economical way to boost living standards.

The pilot programs have improved people's lives. And the market potential is enticing to the energy companies: Some 600 million people in Africa live without reliable access to electricity, according to the International Finance Corp., a division of the World Bank. The big question is how willing governments and nonprofits will be to invest in solar systems.

Testing, Testing

When the sun disappears behind the South African village of Lomshyo,Thandi Mangomisse no longer frets about how much kerosene her lamps are burning.

LIGHT UP THE NIGHT A field of Osram Sylvania solar panels charges LED lanterns like this one in Sindo, Kenya. Siemens AG/Volker Steger

Now, she flicks on two LED ceiling lamps and a lantern, all powered by batteries she charges with two small solar panels on her roof. After living her whole life without electricity, she now can't imagine life without it. The lantern is so integral to her routine that she won't let her grandchildren carry it. "I think they'd break it," says Ms. Mangomisse, 55. "It's too valuable."

The solar panels and lights were a gift from Philips Electronics NV. The Dutch company distributed them to Lomshyo's 71 households and is studying their effect on people's lives to help build a case for future sales of similar systems. In addition to the convenience of electric light, the equipment has provided a financial boost to Lomshyo's residents. Few of them have steady income beyond government welfare grants or modest earnings from banana and mango sales, but now they don't have to spend money on kerosene. One result: Many are now able to buy bread, previously a luxury, to supplement their diets.

In some other pilot projects, nonprofits and local governments are testing the waters by providing some funding for solar-powered systems.

DuPont Apollo Ltd., a unit of Wilmington, Del.-based DuPont Co., last year installed fields of solar panels at a site in Tanzania and four sites in Nigeria to power churches, a middle school and a medical center. The company has sent a team to South Africa to discuss similar installations there.

Osram Sylvania Inc., a unit of Germany's Siemens AG , is using a field of solar panels in Kenya to power rechargeable LED lanterns and overhead household lights in fishing villages on the banks of Lake Victoria. The company plans to replicate the model at 10 more sites in Kenya.

Meanwhile, France's Schneider Electric SA has electrified three villages in Senegal and one village each in Madagascar and Nigeria with solar power. By the end of the year, 20 more villages will be solar-powered in Cameroon, Senegal and Nigeria.

How Big a Market?

The IFC sees the potential for companies to start racking up double-digit annual gains in sales of off-grid lighting systems by 2015. But Arthur Itotia Njagi, manager of the IFC's Lighting Africa program, which promotes private-sector activity in the off-grid sector, acknowledges that energy-company executives still have reservations. "The big guys tend to take a guarded view," he says. "Once they are convinced that there's a market, then they come in big."

The market's size will depend on the willingness of governments and nonprofits to invest on a larger scale in off-grid power systems, says Chuck Xu, chief executive of DuPont Apollo.

Given all the political, economic and financial variables that will influence that willingness, the future is uncertain. But the participation of governments and nonprofits in pilot programs is encouraging, as are the comments of Solomon Lechesa Tsenoli, deputy minister in South Africa's department of rural development. South Africa already supports solar power with guarantees that the state-backed utility will buy the output of large-scale solar-energy plants at a favorable price. It also offers subsidies to homeowners who buy solar water-heating systems. Mr. Tsenoli says the government is interested in similar programs for other solar-power applications, including water pumps and lighting systems.

In Lomshyo, both the promise of solar-powered electricity and the need for more power are obvious. Village leader Teteya Loti Mhlabane is thrilled with the new lighting system but hungry for more. "With the lights, all is all right," he says. "But people here, they still need refrigerators, radios, other things—they still need more power."

Mr. McGroarty is a Wall Street Journal reporter in Johannesburg, South Africa. He can be reached at