The solar-energy industry's huge assembly this week in Orlando buzzed with alternating currents of anxiety and optimism over this year's presidential election.

A common thought at Solar Power International, which bills itself as North America's largest conference and exposition for the solar-energy business, was that the future will stay reasonably bright if President Obama wins a second term, but that it might be lights out if Mitt Romney prevails in November.

"Both campaigns have been pretty vague on their energy plans, but certainly in the past four years we have seen strong leadership from the Obama administration to try to diversify our energy portfolio," said Rhone Resch, president and chief executive officer of the Solar Energy Industries Association, a co-host of the four-day event.

Resch said the industry's labor force has grown in recent years from 20,000 workers to more than 100,000 and has been a major bright spot in the economies of certain states, such as New Jersey.