Saving the Planet - Can Peltier effect assemblies produce energy ?

[Technomaniac]

Many Peltier-effect car fridges are dumped. I wondered if the cells can be made to produce voltage when heated by sunlight.  One side would I assume have to be kept cool. I tried this out briefly with little encouraging result. Don't they use the thermocouple idea, or do I have my Seebeck effect mixed up with Peltier, are they similar or different effects?