KIPTUSURI, Kenya — For Sara Ruto, the desperate yearning for electricity began last year with the purchase of her first cellphone, a lifeline for receiving small money transfers, contacting relatives in the city or checking chicken prices at the nearest market.
Charging the phone was no simple matter in this farming village far fromKenya’s electric grid.
Every week, Ms. Ruto walked two miles to hire a motorcycle taxi for the three-hour ride to Mogotio, the nearest town with electricity. There, she dropped off her cellphone at a store that recharges phones for 30 cents. Yet the service was in such demand that she had to leave it behind for three full days before returning.
That wearying routine ended in February when the family sold some animals to buy a small Chinese-made solar power system for about $80. Now balanced precariously atop their tin roof, a lone solar panel provides enough electricity to charge the phone and run four bright overhead lights with switches.
“My main motivation was the phone, but this has changed so many other things,” Ms. Ruto said on a recent evening as she relaxed on a bench in the mud-walled shack she shares with her husband and six children.
As small-scale renewable energy becomes cheaper, more reliable and more efficient, it is providing the first drops of modern power to people who live far from slow-growing electricity grids and fuel pipelines in developing countries. Although dwarfed by the big renewable energy projects that many industrialized countries are embracing to rein in greenhouse gas emissions, these tiny systems are playing an epic, transformative role.
Since Ms. Ruto hooked up the system, her teenagers’ grades have improved because they have light for studying. The toddlers no longer risk burns from the smoky kerosene lamp. And each month, she saves $15 in kerosene and battery costs — and the $20 she used to spend on travel.
In fact, neighbors now pay her 20 cents to charge their phones, although that business may soon evaporate: 63 families in Kiptusuri have recently installed their own solar power systems.
“You leapfrog over the need for fixed lines,” said Adam Kendall, head of the sub-Saharan Africa power practice for McKinsey & Company, the global consulting firm. “Renewable energy becomes more and more important in less and less developed markets.”
The United Nations estimates that 1.5 billion people across the globe still live without electricity, including 85 percent of Kenyans, and that three billion still cook and heat with primitive fuels like wood or charcoal.
There is no reliable data on the spread of off-grid renewable energy on a small scale, in part because the projects are often installed by individuals or tiny nongovernmental organizations.
But Dana Younger, senior renewable energy adviser at the International Finance Corporation, the World Bank Group’s private lending arm, said there was no question that the trend was accelerating. “It’s a phenomenon that’s sweeping the world; a huge number of these systems are being installed,” Mr. Younger said.
With the advent of cheap solar panels and high-efficiency LED lights, which can light a room with just 4 watts of power instead of 60, these small solar systems now deliver useful electricity at a price that even the poor can afford, he noted. “You’re seeing herders in Inner Mongolia with solar cells on top of their yurts,” Mr. Younger said.
In Africa, nascent markets for the systems have sprung up in Ethiopia, Uganda, Malawi and Ghana as well as in Kenya, said Francis Hillman, an energy entrepreneur who recently shifted his Eritrea-based business, Phaesun Asmara, from large solar projects financed by nongovernmental organizations to a greater emphasis on tiny rooftop systems.
In addition to these small solar projects, renewable energy technologies designed for the poor include simple subterranean biogas chambers that make fuel and electricity from the manure of a few cows, and “mini” hydroelectric dams that can harness the power of a local river for an entire village.
Yet while these off-grid systems have proved their worth, the lack of an effective distribution network or a reliable way of financing the start-up costs has prevented them from becoming more widespread.
“The big problem for us now is there is no business model yet,” said John Maina, executive coordinator of Sustainable Community Development Services, or Scode, a nongovernmental organization based in Nakuru, Kenya, that is devoted to bringing power to rural areas.
Just a few years ago, Mr. Maina said, “solar lights” were merely basic lanterns, dim and unreliable.
“Finally, these products exist, people are asking for them and are willing to pay,” he said. “But we can’t get supply.” He said small African organizations like his do not have the purchasing power or connections to place bulk orders themselves from distant manufacturers, forcing them to scramble for items each time a shipment happens to come into the country.