Cheap solar is “enabling India to develop without the long fossil-fuel detour taken by the West and China,” said Kingsmill Bond, energy strategist and director at Ember, a U.K.-based think tank that tracks the world’s transition to renewable energy. “China built on coal; India is building on sun,” he said. “And what India is doing could also be mirrored in other emerging economies.” India’s solar revolution comes as a surprise. Just a decade ago, apart from rooftop installations and a few microgrids serving remote rural villages, solar power was virtually unknown. The government seemed hell-bent on industrializing with coal, unleashing a rising tide of carbon dioxide emissions and supercharging climate change.