It was the summer of 2010, and she'd come to Africa to test the SunSaluter, a clean-energy device she'd invented in the machine shop in her parents' basement while still in high school. The mechanism rotates solar panels to track the sun by using aluminum and steel strips and heat, rather than electricity, increasing the panels' efficiency by up to 40%.
In the isolated village of Mpala, Full met a woman who owned three solar lanterns but could power only two of them with her standard charger. So Full decided to build a solar charging station for the village and headed to the city of Nanyuki to buy parts. She returned a couple of days later to learn that the woman had been trampled to death by a water buffalo while collecting firewood at night without a light. The woman's husband had taken one of the family's working lanterns, and she'd left the other at home with her children. The third lantern remained uncharged.
"She left two kids behind," Full says. "If I'd gotten there earlier, I could have saved her."
In April 2011, Full learned that she had won a $100,000 Thiel Fellowship, which requires recipients to take a two-year hiatus from college to focus on their projects. She decided to leave Princeton and founded her own company, Roseicollis Technologies, to work on putting the SunSaluter to use in the developing world.
"College will always be there for me whenever I want to go back," says Full, now 20. "But what I'm doing has the potential to impact a lot of people and promote the use of solar. We need that more than anything."
Growing up in Calgary, Canada, Full learned from her father, a newspaper artist, that she could do anything. He shared stories brimming with possibilities: She could be an artist, a chef, a musician. She could build robots or cars or space shuttles. She gravitated toward invention even before she could talk.
Full had become fascinated with solar power by age 10, when she built a solar car from a kit and entered it in a science fair. With almost every fair that followed, a new solar experiment propelled her further, and soon she was tackling solar-panel inefficiency. At one point she arranged panels in a Fibonacci sequence, like branches on trees, which are naturally optimized to collect sunlight. Although that didn't work as planned, it sparked her ingenious idea: to use the sun to warm different metals, then harness their heat differential to rotate the panels to follow the sun, like sunflowers do, as it arcs across the sky.
She became so engrossed in her invention that she had a hard time tearing herself away. "My parents would call in sick for me, so I could stay home from high school and work," she recalls. "Teachers didn't understand what I was doing."
Luckily for her, Princeton's admissions officers did, and she enrolled there in 2009. During her freshman year, she gave class presentations about the SunSaluter, and a professor with a research facility in Kenya invited her to work there that summer and test her device.
In Mpala, Full built two solar charging stations using local scrap metal and bamboo. Each cost about $10 (not including the solar panel or battery), and both are still in operation.
"You don't have to be a genius to invent something you're passionate about," she says. "You just have to do it."
Simi Olabisi can't remember the day she nearly died. But she knows the story by heart. Her dad tells it all the time.
Olabisi was born two months premature--a tiny, barely breathing thing. Definitely in need of an incubator. But the Lagos hospital she was born in, like much of Nigeria, lacked working incubators. "With babies like me," says Olabisi, now 23, "they normally wrap you up and hope you'll live."
There was a children's hospital on the other side of Lagos, so her father scooped up his new daughter and started moving. He managed to flag down a taxi, but they came to a standstill in traffic, so he jumped out and ran several miles through the baking streets. Thanks to his efforts, Olabisi made it into an incubator and survived.
During her adolescence, she and her dad, a chemical engineer, discussed the possibility of an incubator that would be immune to the electrical outages so common throughout the developing world. Unfortunately, reliable solar-powered models cost around $30,000, an amount that's not affordable in rural Nigeria, where 80 percent of the population lives below the poverty line.
After years of globe-trotting (her dad's work took them from Nigeria to Saudi Arabia to Texas), Olabisi enrolled in California's Santa Clara University, where she studied bioengineering. When she had to come up with a senior project, pieces clicked. This was her chance--and her kick in the butt--to pursue what she and her father had talked about. "Without the senior project," she says, "I don't think I'd have gone after this."
Olabisi recruited six other seniors studying different kinds of engineering, and they leveraged their student status to get the resources they needed: Santa Clara University granted $7,400 plus lab space. San Francisco General Hospital donated one of those pricey incubators. Chromasun gave them a panel, and Solar Way Forward offered a free photovoltaics class.
"We approached everyone who helped us out from the angle that we were university students," she says. "That definitely got people's attention."
The group called itself Team Omoverhi, which means "lucky child" in the southern Nigerian language of Urhobo. The four mechanical engineers designed the machine components. An electrical engineer oversaw everything solar-related. Olabisi and a fellow bioengineer developed monitoring systems and kept things infant-friendly: "Sometimes a mechanical engineer would suggest using materials, and I'd say, 'We can't use that. It would burn the baby.'"
To cut the cost down to $2,000, they replaced maneuverability buttons with props and levers, used salvaged computer fans, and made the bed out of a lunch tray. It wasn't yet ready for market, but they had a prototype of a solar-powered neonatal incubator.
Then, in 2011, everyone graduated. Olabisi moved to Chicago, where she now works with semiconductors.
But the project wasn't dead. Santa Clara University, acting as a sort of incubator itself, fostered a smooth handoff to a group of rising seniors, and the original Team Omoverhi became the progenitor of an ongoing project. The class of 2012 shaved dollars and improved efficiency by coming up with a new solar-energy storage system that uses wax-filled pipes (the original design used water). The pipe system costs roughly $45 (down from the water-based system's $250), and most of the materials are commonly available in dump sites.
"The reason we're in this field is to make a positive difference," Olabisi says. "I don't plan to let this idea die. Hopefully we can implement it around the world."
Eden Full text by Carolyn Cotney / photo by Della Rollins; Simi Olabisi text by Jake Abrahamson / photo by Beth Rooney; all illustrations by Timothy J. Reynolds /This article originally appeared in Sierra magazine.