Despite a run-up in a few solar-energy stocks, there's still opportunity in the sector, Ben Kallo of R.W. Baird said Friday.
"SunPower, which is my favorite, is up over 400 percent this year," he said, noting that it had been a laggard all year.
"We've had a big move off the bottom. The past two years were terrible," he said. "A bubble was in 2007 when we were really focused on Europe. That was really the only market, Germany and Italy and Spain. Now, we have a global market, and it's a different business."
Kallo said that SunPower was in a competitive position, citing its profitable business, as well as its $1 billion of liquidity.
"SunPower is a business you can own long-term," he said. "First Solar, similar, but they're a one-trick pony, focused on the utility side of the business."
Still, the solar space was not in bubble territory, Kallo said. "We're in the third inning, maybe."
(Read more: Solar power's a decade-long story: Josh Brown)