This document discusses thermoelectric generators and their developments. It begins with defining a thermoelectric generator as a solid state device that converts heat directly into electrical energy due to a temperature difference across a conductor. It then discusses why thermoelectric generators are needed to capture wasted heat from power stations and other applications. The document covers electronic, mechanical, and mathematical aspects of thermoelectric generators, including how they work, common types like homemade and radioisotope generators, and ways to optimize their performance through materials with high figure of merit values. It concludes with benefits of thermoelectric generators and references used.

1. TOPIC-THERMOELECTRIC GENERATORS AND DEVELOPMENTS
NAME-SANDEEP KUMAR
ROLL NO.-15
2nd SEM

2. WHAT IS THERMOELECTRIC GENERATOR?
 A Thermoelectric generator (TEG) is a solid state device.
 TEG converts heat directly into electrical energy.
 Electricity produce because of temperature difference in conductor
 Thermoelectric generators function like heat engines , but are less bulky and
have no moving parts and are completely silent.

3. WHY WE NEED THERMOELECTRIC GENERATORS ?
 2/3rd parts of ENERGY produce in power station is lost as the heat.
 Heat energy produces by burning of fuels are used to spin turbine which
produce Mechanical energy and further this mechanical energy used to
rotate generator to produce electricity

4.  In thermoelectric generator waste heat is directly converted to electrical
energy.
 SOME THERMOELECTRIC GENERATORS ARE :-
HOMEMADE THERMOELECTRIC
GENERATORS
RADIOISOTOPE THERMOELECTRIC
GENERATOR

5. ELECTRONIC ASPECTS
 A thermoelectric generator is made of many pairs of p-type and n-type elements
 Holes are charge carriers in p-type which have positive seebeck coefficient while in n-type
electrons are charge carriers which have negative seebeck coefficient.
 Voltage potential develop across the p-n junction is proportional to the differences in the
Seebeck coefficient in each element and the temperature of the junction.
 Electrons as the charge carriers in n-type and Holes as the charge carriers in p-type are
move from high heated area of the conductor to low heated area of the conductor

6.  Because of the movements of charge carriers current will produce inside the conductor

7. MECHANICAL ASPECTS
 Heat source (fuel)
 P and N type semiconductor
stack (TE module)
 Heat sink (cold side)
 Electrical load (output
voltage)

8.  The figure shows the construction of thermoelectric power generator.
 There is a burner in which the propane fuel is used as heating source in one side.
 The exhaust is used to transmit a burnt fuel.
 On the other side, a cold junction is kept.
 The thermoelectric module (TE) (consist of number of p-type and N-type semiconductor
pellets connected in series or parallel depending on the served load)) is kept in between
the hot and cold junction.
 The electrical out (load) is taken from the TE module.

9. MATHEMATICAL ASPECTS
FIGURE OF MERIT
 The performance of thermoelectric devices depends on the figure of merit (ZT) of the
material , which is given by
Where
α- Seebeck coefficient,
ρ - the electrical resistivity,
λ - the thermal conductivity, and
T – the temperature

10. HOW TO CONVERT HEAT PRODUCED BY C.P.U OF
COMPUTER INTO ELECTRICITY ?

12. Benefits of TEGs
 no moving elements
 environmental safety
 no working fluids and gases
 low-noise operation
 reduced size and weight
 high reliability — KRYOTHERM guarantees lifetimes of more than 200 000 hours for
our TECs
 smooth and fine adjustment of cooling capacity and temperature
 resistance to mechanical loads
 operation in any spatial position
 easy switching from cooling to heating mode.

13. REFERENCE
 Tianqi Yang, Jinsheng Xiao, Wenyu Zhao, Qingjie Zhang,”Structural Optimization of Two-stage
Thermoelectric Generator for Wide Temperature Range Application”,2011 IEEE.
 ] Xiaodong Zhang, C.C. Chan, and Wenlong Li,” An Automotive Thermoelectric Energy System with
Parallel Configuration for Engine Waste Heat Recovery”, IEEE trasactions on industrial electronics
2010.
 ] L.M. Goncalves and J.G. Rocha,” Application of Microsystems Technology in the Fabrication of
Thermoelectric Micro-Converters”, Solid State Circuits Technologies, Book edited by: Jacobus W.
Swart.
 Joao Paulo Carmo,Luis Miguel Goncalves and Jose Higino Correia, “Thermoelectric microconverter
for energy harvesting systems”, IEEE transactions on industrial electronics, VOL. 57, NO. 3, march
2010

14. THANK YOU