Sanjit "Bunker" Roy founded the Barefoot College in 1972 with the simple notion that everyone deserved light and with the improbable idea that the uneducated women of rural Rajasthan, India, could be taught to harness the sun as solar engineers. Today Barefoot College has trained hundreds of women from 15 Indian states who have in turn helped install more than 11,000 solar systems, providing clean energy, heat, and light to more than 125,000 people.

Solar power is a modern technology, but its application is a return to self-sufficiency that existed for generations, says Roy. "We knew that there was enough knowledge, wisdom, and skill in these communities for them to be self reliant." Educated in one of India's finest universities, Roy grew up an affluent suburb in Rajasthan and decided to dedicate his life to helping the rural poor during the Bihar famine of the 1960s.

Today the Barefoot model has gone global, lighting the poorest communities in Africa and even Afghanistan.

The key, Roy says, is that Barefoot has been able to fly women from villages in Cameroon, Mali, Gambia, Sierra Leone, and Ethiopia to its Indian campus for the six-month training. The Indian government has provided the funding for the program as part of its international aid, a move Roy credits for, among other things, improving Indian—African relations.

Most of the women who boarded the plane to India and Barefoot's Rajasthan campus had never left their village, Roy explains. They were illiterate widows, grandmothers, and mothers. After six months of training in India, they returned to their respective villages knowing how to fabricate, install, and maintain solar lighting systems in their villages. "We're really shifting the relationship these women have with their communities," Roy says. "These women return to their villages as respected role models, and they teach their children and other women how to be solar electric engineers."

With the college's help, the women have formed the Barefoot Women Solar Engineers of Africa, a sorority they've been dubbed the Solar Sisters. "If our methods work in the poorest, most inaccessible places on earth, they can work anywhere," Roy says.

Prigi Arisandi's decade-long campaign to clean East Java's Surabaya River of industrial pollutants has seen great success. But much more work remains, and this fall the battle for the health of the river that supplies drinking water to 1.7 million Indonesians reached a tipping point.