SAN FRANCISCO -- If you want to get a sense of the rise of the solar industry and the decline of semiconductors, come on down to the Moscone Center.

Semicon West, the chip manufacturing convention, and Intersolar U.S. are taking place together in different buildings in the convention complex. Intersolar is pretty well populated and there is traffic on all floors of the convention center. The educational seminars are somewhat full as well. Tigo Energy, which makes a control unit for maximizing output from solar panels, seems to be getting a steady stream of interested parties.

Cut to Semicon. The place is a ghost town.

"It's depressing," said one attendee.

"They are selling stuff they sold back in the '80s," joked another.

"You should try to figure out the male to female ratio," commented another.

Applied Materials has a booth in Intersolar. (We also ran into Applied CEO Mike Splinter and Applied Solar president Charlie Gay here.) Applied, however, does not have a booth at Semicon, according to one person. I have to go check on that and confirm it, but it's an interesting symbolic fact if true.