The document discusses thermoelectric generators (TEGs) that can convert wasted heat into electricity. TEGs use the Seebeck effect where the junction of two different metals produces voltage when maintained at different temperatures. The document proposes a hexagonal TEG apparatus that uses 12 TEG modules to harvest heat from electric generator exhaust gases. Experimental results show the apparatus can generate over 20W of power when the hot side is at 150°C. The TEGs effectively convert wasted heat to electricity and have potential applications where low power is needed.

1. TEGs BASED ELECTRICITY
GENERATION
Presented By:
Geethu Sara Johns
S7A, ECE
Roll no:30

2. INTRODUCTION
 Main problem - Energy crisis.
 Tremendous energy wasted in the form of heat.
 Need to use the wasted energy.
 Increased interest in renewable energy.
 Energy scavengers are modern trend.
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3. College Of Engineering, Chengannur 3Fig 1: WHP

4. TEGs- Thermo Electric Generators
 Solid state device.
 Devices that convert temperature differences into
electrical energy.
 Basic principle-
• SEEBECK EFFECT
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Fig 2: TEGs

5. SEEBECK EFFECT
 When the junctions of two different metals are
maintained at different temperature, the emf is produced
in the circuit. The Magnitude of voltage generated is
proportional to temperature difference
• Discovered by:
THOMAS JOHANN SEEBECK
•
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Fig 3: Seebeck effect

6. CONSTRUCTION
• Major components
• Thermoelectric materials
• Thermoelectric pairs
College Of Engineering, Chengannur 6Fig 4: components of TEG

7. TEGs WORKING
 The simplest TEG 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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Heat input
Hot junction
Cold junction
P-type N-type
Heat ejection
Power output

8. ADVANTAGES
 Waste Heat – Electricity.
 Available 24 hours a day.
 No noise and low maintenance.
 High Reliability.
 Stabilize temperature of devices.
 Increase operation life under all environments.
 Performance output highly scalable.
 Space requirement is only 1/20th of a solar cell.
 Portable power.
 Less weight than a battery.
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9. DISADVANTAGES
 Low efficiency.
 High cost.
 High output resistance.
 Adverse thermal conditions.
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10. APPLICATIONS
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11. PROPOSED MODEL
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 Heat from electric generator exhaust gases is transmitted by
conduction to the hot side of the TEG
 Hexagon format stainless steel apparatus.
• Each side has 2 TEG.
• Total 12 TEGs.
 Cooling system to stabilize the temperature.

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Fig 6. (a) Top view of the assembly of the apparatus TEG;
(b) Side view of the assembly of the apparatus TEG

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Fig 7: Cooling
system and
exhaust gas
apparatus

14. Contd...
 TEG used is TELBP1-12656-0.45
– mixture of Bismuthtelluride (Bi2Te3) and Lead telluride (PbTe)
– Temperature range
• Hot side - 60 °C to ± 360 °C continuously
• Cold side - 60 °C to ± 180 °C continuously
 Temperatures of the TEG sides are read by a Programmable
Logic Controller (PLC) and monitored by a Supervisory
System.
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15. TEMPERATURE MEASUREMENT IN THE
APPARATUS
• Three operating cases :
Case I: operating generator and unloaded with 20 minutes of
operation;
Case II: operating generator 2 minutes with 17 A load;
Case III: operating the generator 5 minutes with a load of 47 A.
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 when the gas inside the exhaust is 313 ºC, the surface temperature is
only 150 °C.

17. POWER GENERATION
• maximum temperature value of the generator with load (150°C)
and with the maximum efficiency value of the cooling side 30 °C
Voc - open circuit voltage generated
Vmp- maximum tension generated
Imp - current
Pmp - power generated by the apparatus.
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18. COOLING SYSTEM
 For TELBP1-12656-0.45
• When Th= 350 °C and Tc=30 °C then, heat flux(Φ) appox.= 247W
and electric power output = 21.7 W
• Heat flow from cold side of TEG to refrigeration box is 225.3 W
or 53.82 cal.s-1
 With time = 60s, mass of water needed for cooling for each TEG from
25-30 °C is
0.654Liters * 12 = 7.848 l/min
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19. FUTURE SCOPE
• Have the potential to harvest energy from every motor in
every factory.
• Will play a key role in the smart cities of the future.
• Work is being carried out on thermoelectric energy
generator that is affordable for common man.
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20. CONCLUSION
 TEG to supply low power electronics (milli watts).
 Waste heat conversion to useful energy beneficial to
present energy crisis.
 Numerous advantages over disadvantages.
 Development in future will lead to interesting
applications.
A revolutionary source for green energy
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21. REFERENCES
• [1] T. R. C. Teixeira, Estudo de um Sistema Híbrido com Colectores Solares Termo-
Fotovoltaicos Acoplados a um Termogerador Eléctrico, Porto,Portugal: FEUP,
2009.
• [2] C. Gould; N. Shammas, A review of thermoelectric MEMS devices for micro-
power generation, heating and cooling applications, UK: Staffordshire University,
2009.
• [3] X. Ji et al., Solution-Chemical Syntheses of Nano-Structured Bi2Te3 andPbTe
Thermoelectric Materials. Journal of Electronic Materials, USA, v.36, n. 7, 2007.
• [4] D. M. Rowe (Ed), Thermoelectrics handbook: macro to nano, USA: CRC Press,
2005.
• [5] O. Junior et al., Analyze the potential of use thermoelectric materials for power
cogeneration by energy harvesting–Brazil, Int. J. of Automation and Power Eng, v.
2, n. 5, p. 303-311, 2013.
• [6] T. Hendricks; W. T. Choate, Engineering Scoping Study of Thermoelectric
Generator Systems for Industrial Waste Heat Recovery, US Department of Energy,
2006.
• [7] Thermonamic, Specification of Thermoelectric Module TELBP1-12656-0.45.
Disponível em: http://www.thermonamic.com/TELBP1-12656-0.45-English.pdf.
Acesso em: 13 mar. 2015
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