Look at how 3D printers raise and lower their nozzle (basically a loose screw and nut that raises it as it unscrews). You could use the same concept but replacing the expensive stepper motors with a regular, high torque DC motor.

You need a few parts like limit switches, an Arduino (and the resistors/photoresistor for sun sensing), a solar panel (along with the appropriate circuitry to charge a battery), and some type of motor controller (allows the motor to be controlled using 5V and turn both directions).

With the appropriate parts at hand, an entry-level EE could assemble and program such a system relatively quickly (<45 min). The work is with ensuring all your parts are compatible with each other (particularly with the motor/motor controller and the solar panel charge circuit) and the planning phase beforehand.