Self-contained temperature regulated solar powered dehydrator

[Spuzzana]

Current project: Looking for information on how to build a self-contained temperature regulated solar powered dehydrator.

Would like to understand the power requirements for a small motor to control convection in the unit.

The unit need to have temperature control so that it can be set at differnet levels dependant on the produce being dehydrated.

Need to know how many solar cells would be ideal to run such a stand alone unit.

Ideas and technical knowledge greatly appreciated.

Thoughts so far:
12v motor
thermo coupling for temperature control
Light bulbs for heat source regulated by thermo coupling switching on/off dependant on temperature.
36 solar cells 3x6 inches placed in series on a single panel that will achieve about 18 volts.