Varun Sivaram

Innovating in the energy industry is what Varun Sivaram calls an “uphill battle,” but he’s nonetheless dedicated himself to helping it advance—and, in doing so, prevent the worst effects of climate change. Over the past decade, he has advised key political leaders, including the governor of New York, and written a book—called a “must-read” by former Secretary of State John Kerry—on how to innovate in the solar-energy space. Now he’s the chief technology officer of ReNew Power, India’s largest renewable-energy company, where he works to accelerate the expansion of renewables in a country critical to global efforts to stem climate change. “I’m determined to help build an ecosystem” for a greener future, he says. —Justin Worland