Some supporters wore green hard hats and waved signs Tuesday equating clean energy and green jobs as industry leaders, policy experts, investors and public officials began a national "summit" meeting in Las Vegas.

About 40 people rallied outside the event at the University of Nevada, Las Vegas, before John Podesta, president of the Washington, D.C.-based Center for American Progress, urged event organizers to focus on untapped economic potential.

"The focus now has got to be on getting these worlds and mechanisms together to finance innovative, renewable technology," said Podesta, the moderator of the first panel at the National Clean Energy Summit.

Retrofitting just 40 percent of the country's homes and commercial properties for energy efficiency would create 625,000 jobs over a decade, Podesta said.

Senate Majority Leader Harry Reid said a greater push behind renewable energy could ease the nation's security problems and help overcome economic woes.

The Nevada Democrat and the Center for American Progress Action Fund are hosting the meeting, which is the third in a series of national clean energy conferences held in Las Vegas.

Other panels on clean energy, investments and jobs were scheduled.

Podesta was White House chief of staff to President Bill Clinton and headed President Barack Obama's presidential transition team.

Other high-profile participants were to include U.S. Chamber of Commerce President Thomas Donahue and Texas oilman T. Boone Pickens.

Jim Murren, chief executive officer of MGM Resorts International, said consumer demand for sustainable innovation helped make MGM's CityCenter resort on the Las Vegas Strip one of the world's largest green projects.

"What happens here does not stay here as it relates to energy," said Murren, who boasted of sold-out rooms over the Labor Day holiday weekend.