New Delhi, July 29 -- When ReNew set up shop back in 2011, renewable energy in India was little more than an ambitious buzzword. Solar tariffs were hovering around an eye-watering Rs.15 to Rs.17 per kilowatt-hour, wind power was barely breaking even, and coal ruled the roost.

Fast forward 15 years, and the economics have flipped entirely. Today, solar and wind are significantly cheaper to build and run than coal-based power plants. Yet, despite this breakneck expansion, India finds itself at an intriguing paradox.

While green power generation has scaled rapidly, electricity accounts for only 20% of India's overall energy basket. Out of that slice, wind and solar meet less than 15%. In real terms, renewables currently power just 3% of In...