What you are describing (and what OP is asking about) is actually a Peltier element. Aka thermoelectric effect.
Piezo electric is different and uses a quartz crystal to generate a brief electric current from a physical impact. This is the mechanism of many igniters used in gas BBQ grills and heaters.
Blrja6040 t1_j4lepeq wrote
Reply to comment by [deleted] in How do non electric heat operated fans work? by ranman12953
What you are describing (and what OP is asking about) is actually a Peltier element. Aka thermoelectric effect.
Piezo electric is different and uses a quartz crystal to generate a brief electric current from a physical impact. This is the mechanism of many igniters used in gas BBQ grills and heaters.