A Bridgewater company is betting the road to success goes through some of the world's poorest countries.

With $100,000 in funding from the World Bank, a group of graduate students at the Massachusetts Institute of Technology has developed a solar energy system that generates electricity, heating, and cooling -- using little more than sheet metal and automobile parts. They hope to turn their invention into a viable business, under the name Promethean Power.

"Can this be a multi-hundreds of millions of dollars company? The potential is there," said Sorin Grama, an immigrant from Romania who just completed a master's degree in system design and management at MIT's Sloan School of Management.

Grama created Promethean Power's business plan, and it was good enough to win a $10,000 prize in MIT's annual entrepreneurship competition.

The idea behind Promethean Power came from Matthew Orosz, an MIT graduate student who has worked as a Peace Corps volunteer in the African nation of Lesotho. Orosz wanted to provide electric power, refrigeration, and hot water to people without electricity. He and some MIT colleagues designed a set of mirrors that focus sunlight onto tubes filled with coolant. The hot coolant turns to pressurized vapor, which turns a turbine to make electricity. The leftover heat can be used to warm a tank of water and to run a refrigerator or an air conditioner, using a gas-absorption process that chills liquid ammonia by first heating it.

Such a system needs pumps and coolant condensers, which may be hard to obtain and maintain in a poor country. But Orosz designed his system to rely on components for cars. Automobiles are common even in poor countries. Spare parts are readily available, and so are people with skills to replace things that break.

Grama estimates that building one of the systems will cost about $5,000, and that the price could fall to $3,000 if the solar systems are mass-produced. Yet each would produce enough power to run a small business, such as a grocery store or restaurant. Aside from electricity to run lights, the chemical refrigerator could be used to preserve food, and the leftover heat would deliver hot water.

Because the system produces power without adding greenhouse gases to the atmosphere, Promethean Power officials think system operators will be able to sell "carbon offsets" on global energy markets. Companies that produce lots of carbon dioxide emissions sometimes purchase offsets to subsidize nonpolluting energy alternatives. If Promethean Power users can tap into the offsets market, it will mean a steady stream of extra income.

But Orosz, who's in Lesotho working on two prototype systems, said the system is far from ready for commercial use. "We got the award to try to demonstrate that the concept is valid," said Orosz, but "it's not a slam dunk." The machinery inside the prototypes uses more energy than they presently produce. So Orosz is bench-testing pumps and condensers from a host of automotive suppliers. He's looking for a combination of components that will produce enough surplus energy to make the system pay.

Daniel Alexander, founder of the venture capital firm CambridgeLight Partners, served as a judge in the MIT competition. He said it's too soon to tell whether Promethean Power can be a viable business. But he likes what he's seen. "Their technology is quite lovely," Alexander said. He was especially impressed by the solar power system's relatively low-tech design. "Everything else we get is nano-this and nano-that," he said.

Grama is off to India, where he hopes to find small manufacturers to mass-produce them. India, not Africa, will be Promethean Power's first beachhead, because the country has a well-established "microlending" system. Microlenders provide small loans to the kinds of start-up businesses that would benefit from a Promethean Power system.

"We want to be profitable by the fourth year of operation," Grama said. Becoming an affordable-energy giant, though, will take a little longer -- a decade, he figures.