Evans Wadongo is not yet 25 but has already changed the lives of tens of thousands of his fellow Kenyans living in poor rural communities by supplying them with solar lamps.
As a child growing up in west Kenya, Wadongo struggled to do his homework by kerosene lamp. He was caned at school if his family ran out of fuel for the lamp, and he permanently damaged his eyesight by sitting over the smoky fumes when they did have kerosene.
But his father, whom he describes as a teacher who was "very strict" and "my greatest inspiration", saw that he completed his studies and made it into university.
Once there, Wadongo started wondering how to improve conditions for children in communities similar to his home village -- and there are many. Though Kenya is one of the richest countries in east Africa, more than half the population lives on less than a dollar a day.
The young man had always wanted to help people but did not have the stomach to go into medicine, so he opted for engineering. He was only 19 when he invented his first solar lamp after using part of his student loan to buy what he needed.
"Then, I never thought it would take off on this scale. I just wanted to take one to my grandma," he recalled.
Some 15,000 lamps have been turned out since production started in 2004, and Wadongo says his goal is to hit 100,000 by 2015.
"I started in the village where I grew up and I saw kids going from primary into high school," he told AFP.
He has no time for Kenya's political class, accusing them of "wanting people to remain poor so that they can stay in power".
For Wadongo, the lamps are not an end in themselves, but rather "a way to lift people out of poverty."
He and his team from the "Use Solar, Save Lives" project start by identifying impoverished communities that rely for lighting on kerosene lamps -- when they can afford the fuel. They hand out 30 lamps to a community association, often a women's group, and encourage the locality to pool the money each family has saved by no longer buying kerosene.
When the fund accumulates the group can use it for a project, such as fish farming or rabbit breeding.
Nomadic communities get a special model of lamp for easier transport.
Typical is Chumbi village, some 50 kilometres (31 miles) outside Nairobi where Wadongo gets an enthusiastic welcome.
"They all want lamps," smiles Agnes Muthengi, a representative from a local association, the Kalima Kathei Women's Fellowship, who accompanied him to the village.
Jennifer David, 47, lives in a mud-brick house flanked by outbuildings made largely from scrap metal.
Next door, a field of maize wilts for lack of water. David's husband is a casual day labourer and work is hard to come by. Her only other source of income is a fledgling rabbit breeding business. But with one rabbit only fetching the equivalent of one euro ($1.3) locally and one of the five children sick and in a home, life is a struggle.
A slogan painted on rusted corrugated iron informs the visitor that the inhabitants "trust in Jesus". Hanging on a post in the yard, one of Wadongo's lamps is charging.
"Since I got this lamp things have changed," David told AFP. "Before I was using kerosene. It smelled and gave off a lot of smoke and I was using a lot of money to buy the kerosene."
Now, her children can read and study in the evening, without cost or nuisance.
Wadongo plans to extend his project to neighbouring countries -- Uganda is next on the list. He is already training interns, not only from Kenya and elsewhere in Africa but also from US universities. He also aims to decentralise production of the lamps, thus providing work for unemployed youths.
The young engineer is also planning a "model" village at Nyaobe in the west of this country, which straddles the equator. Residents will be hooked up to a local solar-powered grid and will have access to Internet.
"If every one of us started thinking about others before thinking about ourselves the world would be better," he says.
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