IIRC TECs have an efficiency of around 7% and the stock AC in your car is much higher than that.
The fans etc that come on already make use of your solar and probably pull about as much power as the solar makes.
So no; don't use TECs.
What you might consider is:
- The 'auto switch off aircon' (and alternator etc) during acceleration and 'auto switch it on during slowing/braking' when you have 'free energy' if/when you gear down.
- Evaporative cooling using an ultrasonic mist maker you put in that interior air intake under the grille near your wipers where there's a high pressure area.
NB that Evap won't work in a humid climate.