It’s only logical, given the fast pace of growth in the U.S. solar industry, that a four-year-old solar conference in San Francisco would have ballooned to draw more than 22,000 attendees and 800 exhibitors.

While logical, it’s still an impressive accomplishment for Intersolar North America to have such a following in such a short time. The conference will draw this impressive crowd at the Mascone Center in San Francisco next week, July 12 to 14.

The event is California’s largest solar expo and one of the country’s biggest. It brings solar experts, enthusiasts and entrepreneurs from around the globe together.

“Intersolar has a very interesting mix of visitors because it has the international, yet local flair,” said Mariel Firmacion, spokeswoman for the event. “People from all over the globe will be traveling to San Francisco to participate, learn and network with some of the brightest minds in the industry.”

Intersolar North America is part of a series of worldwide exhibitions in Munich, Mumbai and Shanghai. Together the events comprise the largest solar event in the world.

“Intersolar North America presents its visitors a chance to meet with the big international solar companies alongside innovative start ups,” Firmacion said.

Hot topics at this year’s event are likely to include building-integrated solar photovoltaics, Firmacion said, and concentrating photovoltaic technology.

Building-integrated solar is a relatively new topic. Within the last year, several companies have announced advancements in and research on technology that will turn the windows on skyscrapers into solar energy generators. One company even installed a test section of its solar window technology in the former Sears Tower in Chicago.

“Concentrating photovoltaic technology has made great strides recently as well,” Firmacion said. “It’s emerging as a technology to watch with forecasted utility-scale installations to grow to more than 1 gigawatt by 2015. CPV has won several project bids in recent years.”

Concentrating Photovoltaics employ mirrors to use the sun’s rays to heat a liquid and generate steam the same way coal-fired electricity plants do. Many of the world’s largest new solar projects are using CPV technology.

Firmacion said other hot topics will include smart grid and storage, transmission issues, module testing and certification, and a lot of focus on utility-scale projects, which have been a fast-growing segment of the U.S. market, she said.

This year’s conference will be the biggest yet with tremendous growth from last year’s 500 exhibitors to this year’s 800, Firmacion said.