That limits how much people can do in a day, whether its homework or handicrafts.

Tapping local ingenuity

To help, Roy says he did what World Bank and U.N. aid projects often fail to do – that is, tap into the local ingenuity he sees every day.

"You'll find it everywhere in India, this infinite capacity to be able to improvise and fix things without having gone through any formal education," he added. "They have this incredible inbuilt skill that we haven't been able to define, appreciate or respect yet."

Women built solar cooker

As if to illustrate their inbuilt skill, Roy points out a solar cooker that some of the women at Barefoot College helped design and build. At its heart is a "solar tracker" made of old bicycle sprockets, springs and rocks. It allows a parabolic mirror – also homemade and about the size of a satellite TV dish – to follow the arc of the sun, focusing its rays into an aluminum stove. All the meals at the college are cooked on it.

One of its main designers is Sita Devi, a 30-year-old mother of two with only a third-grade education.

She says she wanted to make a solar cooker with materials that are easily available, even in remote villages. She says the cooker saves time – and the environment – by reducing the need for women to wander outside the village in search of firewood for cooking.

In this song, Devi and other women of the Barefoot Brigade extol the benefits of their solar cookers and lamps.