Buffalo trampled over it? Rain drenched it? Child dropped it? No problem! This solar flashlight can endure it all, said Bassi in a pitch to her neighbors in rural India to convince them to power their homes with clean energy instead of polluting fuels.

Bassi is one of 2,500 "Solar Sahelis," or solar women friends, who fan out to different villages and persuade families to use solar energy in the western desert state of Rajasthan, which sees about 300 days of sunshine every year.

With unreliable electricity and hourslong power cuts every day, many rural families in Rajasthan are often forced to rely on candles, kerosene oil lanterns or burning wood, which emit soot and noxious fumes.