The document discusses thermoelectric generators (TEGs), which convert temperature differences directly into electrical power via the Seebeck effect. TEGs have various applications such as powering low-power electronics by harvesting waste heat from sources like the human body, car exhaust, and industrial machinery. While TEGs have advantages like solid-state operation and maintenance-free use, their efficiency is still relatively low compared to other power generation methods. Research continues on improving TEG materials and designs to increase their performance and viability.

1. THERMOELECTRICTHERMOELECTRIC
GENERATORS (TEG)GENERATORS (TEG)
Presented by:
JIYADH.K.SABEER
NO: MTALEEE032
THERMOELECTRIC GENERATOR
Date: 25/02/2015
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2. 2
 Introduction
 Basic Principle of TEG
 Applications
 Advantages
 Disadvantages
 Conclusion
 Reference
OVERVIEW
THERMOELECTRIC GENERATOR

3. INTRODUCTION
 Energy crisis-main problem.
 Increased pollution & population.
 Tremendous energy wasted in the form of heat.
 Constant uninterruptable power requirement.
 Distorts the output performance.
 Efficiency decreasing in electronic systems.
 Increased interest in renewable energy.
 Energy scavengers are modern trend.
SOLUTION???SOLUTION???
THERMOELECTRIC GENERATORSTHERMOELECTRIC GENERATORS 3
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4. 4
Fig.1 Energy Statistics
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5. WHAT IS TEG??
 Devices that convert temperature differences into
electrical energy.
 Basic principle – “SEEBECK EFFECT” (power
generation).
 PELTIER EFFECT
( Heating
and cooling purposes)
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Fig. 2 TEG Module
THERMO ELECTRIC GENERATOR

6. Working principle of TEG
Seebeck effect
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Fig. 3 Working Principle
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N-Bi2Te3
P-Sb2Te3

7. THERMO ELECTRIC POWER GENERATION
 It is based on SEEBECK EFFECT.
 Heat is applied to a circuit at junction of different conductors a
current will be generated.
 THOMAS JOHANN SEEBECK invented Seebeck effect in 1822.
 The Magnitude of voltage generated is proportional to temperature
difference and depended on type of the conducting material
 Seebeck coefficient defined as the open circuit voltage produced
between two points on a conductor when a uniform temperature
difference of 1k is applied between those points.
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8. Thomas Johann Seebeck [ 1770 – 1831 ]
8
Figure 4

9.  The simplest thermo electric generator
consist of thermocouple of n type and p
type elements connected electrically in
series and thermally in parallel.
 heat is input from one side and rejected
from other side.
 a voltage will be generated across
Thermocouple.
 The magnitude of the voltage is
proportional to the temperature
gradient.
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Figure 5

10. Seebeck Effect
10
Figure 6

11. THERMO ELECTRIC HEATING AND
COOLING
 These are based on PELTIER EFFECT
 That is current is passes through a two dissimilar conductors there
will be a rise or fall of temperature at junction depending on
direction of current flow
 Peltier effect discovered by Jean Peltier in 1834
 Electrons moved from p type to n type, material absorbing thermal
energy from cold junctions.
 Electrons dump their extra energy at hot junction as they flow from n
type to p type material through electric connector.
11

12. Jean Peltier [ 1785 - 1845 ]
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Figure 7

13. Peltier Effect
13
Figure 8

14. FABRICATION OF TEG
 Highest performance can be obtained in presence of heavily doped
semiconductor such as Bismuth and silicon germanium.
 TEG must be
a) Small in size
b) Light in weight
c) High silicon compatibility.
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Figure 9

15.  Fabrication process of thermo electric microconverters
1. The p type Sb2te3 film is deposited by thermal co-evaporation
followed by Nickel
2. Photo resist and P type elements are patterned by photolithography.
3. Nickel is etched in chromium etchant, a Thermoelectric film is
patterned by wet etching HNO3.HCL and photo resist is removed.
4. The n type film deposited by co evaporation followed by 100m
nickel layer.
5. Photo resist is applied and patterned by photolithography for n type
element.
6. N type is etched in HNO3 and photo resist is removed, contacts are
deposited starting with a layer of nickel followed by 1µm of
aluminum and photo resist is removed.
7. A protective layer of Si3N4 can also be deposited by low-temperature
hot wire chemical vapor deposition and patterned depending on
application. 15

16. 16
Figure 10

17. 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
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THERMO ELECTRIC GENERATOR
 A good thermal material must have
1. High Seebeck coefficient,
2. Low electric resistivity,
3. Low thermal conductivity.

18. CALCULATION
• For a single thermo couple
 Open circuit voltage V = ( @ * dT) ……….. (1)
• @ – Seebeck coefficient= dV/dT (volt/Kelvin )
• dT – diff in temp = Th-Tc (Kelvin)
 Current through the load, I= @ * DT ……….. (2)
Rc+RL
• RL – load resistance
• Rc – internal resistance
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19. 19
 Efficiency of the generator (Eg) is:
Eg = V x I ..............(3)
Qh
• The total heat input to the couple = Qh
T c = Temperature at cold junction
T h = Temperature at hot junction

20. 20
Applications Wireless EEG
Fig.18 Wireless EEG
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Thermoelectric
micro
converter
Power
conditioning
Ultra low
power EEG
amplifiers
Signal
processing
and control
RF CMOS
transceiver
@2.4GHz
Block Diagram of TEG -EEG
system
Figure 19 Block diagram

22. • Human body temperature 270
c to 360
c
• Forehead & Nose have little high temperature
• Epilepsy or Sleep monitoring
• Patient while doing exercise
• Regular medical data automatically recorded
• Comfort for the subject ( human or animal )
• No need to replace or recharge the battery
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23. • Air conditioner business developed recently
• CFC emission increased
• Alternative should be found out
• Peltier effect is being used
• Beneficial to use because
1. Low maintenance
2. Long life
3. No moving parts
4. Can be used for microchip
cooling
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TEG for Cooling
Figure 15

24. Low power devices such as wrist watches and hearing
aids
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Fig.16. Thermic watch
THERMO ELECTRIC GENERATOR

25.  Easy to use
 Maintenance free
 Long life
 Good for daily use
 Uninterruptable power so no risk
 Watches were first brought by
SEIKO & CITIZEN
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Figure 17 thermic watch by SEIKO

26. Automotive thermoelectric generators
fig 11 TEG in the exhaust of an automobile
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27. 27
Figure 12

28. 28
Thermo Electric Generator
stove
Figure 13

29. 29
Thermoelectric Phone
Charger
Figure 14

30. Advantages
 Solid state construction, no moving part, no vibration.
 Available 24 hours a day.
 No noise and low maintenance.
 Convenient power supply.
 Stabilize temperature of devices.
 Increase operation life under all environment.
 Space and military applications.
 Performance output highly scalable.
 Waste Heat – Electricity.
 Space requirement is only 1/20th
of a solar cell.
 Portable power.
 Less weight than a battery.
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31. Disadvantages
 Low efficiency.
 High cost.
 High output resistance.
 Adverse thermal conditions.
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32. 32
Conclusion
THERMO ELECTRIC GENERATOR
 TEG to supply low power electronics ( milli watts).
 Waste heat conversion to useful energy beneficial to
present energy crisis.
 Numerous advantages over disadvantages.
 Variety of application field.
 Introduction of nanotechnology.
 Development in future will lead to interesting
applications.

33. E e-books available Google
1. Waste Energy Harvesting: Mechanical and Thermal
Energies
• By Kong Ling Bing, Tao Li, Huey
Hoon Hng, Freddy Boey, Tianshu
Zhang, Sean Li
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34. Reference
[1] 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
[2] Tom Torfs, Vladimir Leonov, Refet Firat Yazicioglu,Patrick Merken, Chris Van Hoof,” Wearable
Autonomous Wireless Electro-encephalography System Fully Powered by Human Body Heat”, IEEE
SENSORS 2008 Conference.
[3] 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.
[4] Tianqi Yang, Jinsheng Xiao, Wenyu Zhao, Qingjie Zhang,”Structural Optimization of Two-stage
Thermoelectric Generator for Wide Temperature Range Application”,2011 IEEE.
[5] 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.
[6] Luciana Wasnievski da Silva,and Massoud Kaviany,” Fabrication and Measured Performance of a
First-Generation Microthermoelectric Cooler”, Journal of microelectro mechanical systems,VOL. 14,
NO. 5,october 2005.
[7] Design and Fabrication of Heat Storage Thermoelectric Harvesting Devices M. E. Kiziroglou,
Member, IEEE, S. W. Wright, T. T. Toh, P. D. Mitcheson, Senior Member, IEEE,Th. Becker and E.
M. Yeatman, Fellow, IEEE 2012
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