How Do Thermoelectric Generators (TEGs) Work?

Seebeck Effect

The Seebeck Effect produces an electric current when dissimilar metals are exposed to a variance in temperature. Seebeck effect applications are the foundation of thermoelectric generators (TEGs) or Seebeck generators which convert heat into energy. The voltage produced by TEGs or Seebeck generators is proportional to the temperature distance across between the two metal junctions.

Thermoelectric generators are solid-state heat engines made of pairs of p-type and n-type elements. The p-type elements are made of semiconductor materials doped such that the charge carriers are positive (holes) and Seebeck coefficient is positive. The n-type elements are made of semiconductor material doped such that the charge carriers are negative (electrons) and the Seebeck coefficient is negative.

Energy Generation

When a p-type element electrically connects to the n-type element, the mobile holes in the p-type element “see” the mobile electrons in the n-type element and migrate just to the other side of the junction.

When one electrically connects a p-type element to the n-type element, the mobile holes in the p-type element “see” the mobile electrons in the n-type element and migrate just to the other side of the junction. For every hole that migrates into the n-type element, an electron from the n-type element migrates into the p-type element. Soon, each hole and electron that “switch sides” will be in equilibrium and act like a barrier, preventing more electrons or holes from migrating. This is called the depletion zone.

Benefits

Thermoelectric power generation provides reliable, renewable energy for a variety of industries and applications. Benefits includes:
 
  • Easy installation
  • Safe storage (safe or safer than most existing batteries)
  • Can operate in any geographic location
  • Cost effective
  • Low maintenance
  • Can be produced in bulk

Applications

EVERGEN Series
 
II-VI’s EverGen Series Thermoelectric Generators is a complete range of thermoelectric-based energy harvesting devices that offer customers a low-cost, zero-maintenance power solution for wireless sensor applications. By converting small degrees of temperature difference into milliwatts of electrical power, II-VI’s line of thermoelectric energy harvesting solutions can perpetually power wireless sensors for the lifetime of the application. This green innovation offers a solid-state, reliable energy source for sensors, actuators, valve solenoids and other small devices by recycling wasted heat.
Thermoelectric Generator (TEG) Modules (Thermocyclers)
 
Because solid state Thermoelectric Generator (TEG) modules are designed to provide DC power to a wide range of devices with high reliability. TEGs utilize unique construction techniques to survive a high number of thermal cycles and 200°C continuous hot side operation. TEGs are applicable in a variety of industries including automotive, medical, industrial, oil, gas, and mining, and telecommunications