Overview:The energy market has an estimated global value of $6 trillion — a number that could be greatly affected by an increase in renewable sources, especially solar. In his first television project since retiring as host of CBS’s “The Late Show,” David Letterman travels to India for the first time to find out what the world’s soon-to-be most populous country is going to do to expand its inadequate energy grid, power its booming economy and bring basic electricity to 300 million citizens who have never plugged in. Letterman interviews the prime minister, travels to rural villages where power is a luxury few can afford and finds out why the U.S. may play a key role in India’s energy future. “Saturday Night Live” cast member Cecily Strong travels to Florida and Nevada to investigate what’s blocking the growth of solar energy in the U.S. — and she gets the real story from industry insiders and a retired commissioner now willing to tell their stories.