Are solar-energy materials in short supply?

At the Intersolar and Greentech Media conferences, J. Michael Horowitz of the Stanford Group moderates a discussion on solar-thermal technologies and the challenges solar-energy companies face when acquiring materials. Panelists include Bob Cart of GreenVolts, Andrew McMahan of SkyFuel, Robert Morgan of Ausra, Suvi Sharma of Solaria, and John Woolard of BrightSource Energy.