Inside the panel is a load of balls. Every ball has a mirror, and all the balls move together to point their mirrors as directed by the controller. In a complete system each panel points in a slightly different direction in order to focus the sun to the same spot as every other panel. For more details see 'How It Works'.
The panels are mass produced items, easily boxed and delivered. New panels can be added to an existing installation easily (assuming you have room), and damaged panels are easy and inexpensive to replace.
Australian patent no. 722115, US Patent no. 6227673, Patent pending Europe