Close to 20,000 attendees were expected by Thursday at the Solar Power International convention and trade show in San Diego.

The solar industry is on a roll. Recent news of an eight-year continuation of tax credits for solar installations were the main topic of discussion at this week’s Solar Power International convention and trade show in San Diego.

The event broke all kinds of records: close to 20,000 attendees (with 20 percent of them coming from outside the U.S.) were expected by the show’s end on Thursday. This year’s show had three times as much exhibit space as last year’s show, and it was announced that there’s a 450-company waiting list to get into the show.

Keynote speaker former general Wesley Clark, called solar energy “the bright spot of our economy” during a week in which the DOW JONES average continued its roller coaster ride.

While approximately 70 percent of the exhibitors were on the photovoltaic side of the solar industry, the remaining 30 percent on the solar thermal side found traffic steady throughout the first two days. Wednesday evening was to be “public night” at the show.

Sponsored jointly by the Solar Electric Power Association and the Solar Energy Industries Association the show has grown from 60 exhibitors five years ago to 425 this year. Next year’s event at the San Jose, Calif., convention center and surrounding facilities will accommodate more than 800 companies.

SEIA President Rhone Resch, praised the entire industry for its efforts to get the tax credits extended, noting that it took 21 months and 17 votes before the extensions finally passed both houses of Congress and were signed by the President.