Sun-A-Ray Trackers uses 110v AC controllers and motors for movement.  We have chosen this due to the variation of DC voltage outputs that can occur with today’s MPPT charge controllers.  The AC controller has the ability to return the array to the east position after the sun has set giving it an advantage by tracking the sun from sunrise to sunset; allowing the end user maximum production from the array. 

One of the advantages of our larger sized arrays is that they match up well with a single grid-tied inverter which can be mounted at the tracker, giving easy access to 110v AC power.  In an off-grid application it would be easy to run an extra conduit to bring 110v power from the inverter out to the array.  From a power usage stand point it is irrelevant, if you are pulling DC power from the PV panels or back feeding power from the inverter.  If you choose a tracker you are already looking to maximize the total output from the array so why not have the tracker facing east and ready to go when the sun rises?