On the final unit I want to put 4 troughs on a tracking unit tied to a thermostat & a plc. Which like you said can be rotated out of the sun if temperature gets to hot.

  I also think with a little planning the tracking unit can be made to rotate out of harms way in a storm to avoid hail damage.

   The tracker can also be made to rotate the troughs down at night to avoid snow accumulation in the winter.

   Lots of posabilities!  Still in the R&D stage & having lots of fun!