The solar business is basking in new Recovery Act incentives.

BOULDER, Colo.—It was Feb. 17, and Blake Jones was in Denver to make a speech. When you're the president of the largest solar company in the Boulder-Denver corridor, this whole speech thing isn't unheard of. But this was Feb. 17, 2009. This was the day the stimulus was going to be signed. This wasn't a normal speech; it was an introduction of the president of the United States. Barack Obama needed a warm-up act, somebody who could put a face on both the stimulus and the future of the American economy. Blake Jones was that guy.

And so he got up on stage and explained why an unknown like him was asked to introduce the president. His voice cracked a bit as he explained that he is the president of Namaste Solar. His company had grown accustomed to torrid growth (from three to 55 employees in three years), but then the recession hit. The fourth quarter of 2008 was ugly: hiring freezes, budget cuts, the threat of layoffs. No money in the capital markets means nobody can afford to install solar systems. And no installations means no profit for Namaste, a company that had been in the black for three years running.

But the stimulus, Jones said while standing in front of Obama and Joe Biden, would change all that. His boilerplate was pitch-perfect: "Now, because of the stimulus bill that the president will sign today, our pessimistic outlook has been injected with new hope and optimism," he said. "This stimulus bill will immediately benefit companies like ours." Before the bill became law, the administration had chosen him to be the final person to give voice to the bill's promise.

Five months later, the promise has been fulfilled. Talking with Jones in his Boulder office is like talking to a born-again optimist. The stimulus that has beguiled and disappointed so many others has helped him find his way back. Jones patiently talked me through the stimulus' solar treatment for an hour and a half, and he couldn't say enough good things about it. If the solar industry ever fulfills its potential as a national energy source, the stimulus will deserve the credit. It could become one of the bill's chief legacies.

To understand why, come with me to a rooftop in Superior, Colo. (obviously the best city in the state). Sun shining, Rocky Mountain foothills looming, indie-rock radio playing. Four men are up here, carrying solar panels up a 20-foot ladder as if they're two-by-fours. All of them are wearing sunglasses, a required uniform when you spend all day staring at things that stare at the sun. The panels themselves are a tessellation of rounded squares, a splash of navy blue and white atop a dichromatic gray-black roof.