Why are Peltier tiles (TEG not TEC) so inefficient at producing electricity?

The Peltier Effect (PE) relies on the movement of electrons (and holes) in a circuit that involves a semiconductor material. This movement is statistical in nature. In other words the transference of thermal energy [heat] is by the mechanical and frictional interaction of the movement of these particles. There is a lag in time with such interactions and only a small portion of the energy is transferred at a time.

It's like waiting for a bouncing ball to stop bouncing if you drop it from some height above the floor. It will come to a stop, but it takes time. However in the PE the motion is maintained by some outside power source. This way the effect can take place fully per the type materials and bulk that is involved.

The only way to improve this would be to find other materials, or another physical mechanism that duplicates the effect without its quantum mechanical trappings.

Peltier Tiles