Typically solar panels are mounted in a fixed orientation which works pretty good. However, when you want to ring every bit of energy out of the sun it is best to use sun trackers. Solar trackers tend to be 40 percent more energy efficient than fixed mount systems. A solar/sun tracker follows the sun through the sky adjusting the panels angle and direction. Usually this means a bank of panels, or a single panel, have a tracker assigned to them, this works well, but requires multiple motors and trackers for each array of panels.
The QBotix Tracking System (QTS) pictured above (and in video after the break) uses a robot (Solbot) on a rail to visit each panel on 40-minute intervals. The robot goes to each panel adjusting its angle and direction. If the robot isn't feeling well or breaks down, there is another robot on standby ready to help out.