lalkrishn tripathi Malvian Seminar Report

Advance Solar Energy System with Themoelectrical Generator

1. Advance solar Energy System with Thermoelectric Generator 1 Presented by: LALKRISHN TRIPATHI ROLL NO.- 2017032012 THERMOELECTRIC GENERATOR Madan Mohan Malaviya University of Technology, Gorakhpur (U.P.)- INDIA Date: 06 /02/201 9 Guided by-L.B.PRASAD SIR AND BRIJESH KUMAR SIR

2. Introduction Basic Principle of TEG Applications Advantages Disadvantages Conclusion Reference 2 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. S O LU T IO N ??? T H E R MO E L EC T R IC G E NER A T O R S 3 THERMO ELECTRIC GENERATOR

4. 4 Energy Statistics THERMO ELECTRIC GENERATOR

5. WHAT IS TEG??  Devices that convert temperature differences into electrical energy. Basic principle – “SEEBECK EFFECT” (power generation). PELTIER EFFECT ( Heating and cooling purposes) 5 TEG Module THERMO ELECTRIC GENERATOR

6. Working principle of TEG Seebeck effect 6 Working Principle THERMO ELECTRIC GENERATOR N-Bi 2 Te 3 P-S b 2 T e 3

7. THERMO ELECTRIC POWER GENERATION 7 It is based on SEEBECK EFFECT . He at i s appl i e d t o a c i r cuit at j u nct i on of dif f e r ent 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 .

8. Thomas Johann Seebeck [ 1770 – 1831 ] 8

9.  The simplest thermo electric generator consist of thermocouple of n type and p type elements connected electrically in series and thermally in parallel. 9 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.

10. Seebeck Effect 10

11. THERMO ELECTRIC HEATING AND COOLING 11 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.

12. Jean Peltier [ 1785 - 1845 ] 12

13. Peltier Effect Figure 8 13

14. FABRICATION OF TEG Highest performance can be obtained in presence of heavily doped semiconductor such as Bismuth and silicon germanium. TEG must be Small in size Light in weight High silicon compatibility. 1 4

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

16. 16

17. FIGURE OF MERIT THERMO ELECTRIC GENERATOR  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  A good thermal material must have High Seebeck coefficient, Low electric resistivity, Low thermal conductivity. 17

18. CALCULATION For a single thermo couple 18  Open circuit voltage V = ( @ * dT) ……….. (1) • • @ – Seebeck coefficient= d T – d i f f in t e m p = d V / dT Th-Tc (volt/Kelvin ) (Kelvin)  Current through the load , ……….. (2) I= @ * DT Rc+R L • • R L – load resistance Rc – internal resistance

19.  Efficiency of the generator (Eg) is: ..............(3) Eg = V x I Qh The total heat input to the couple = Qh T c = Temperature at cold junction T h = Temperature at hot junction 19

20. Applications Wireless EEG THERMO ELECTRIC GENERATOR Wireless EEG 20

21. T h erm o el e ctric mi c ro co n verter P o w er c o nd i t i on i ng Ultra low power EEG amplifiers Signal processing and control RF CMOS tra n s c eiv e r @ 2.4GHz Block Diagram of TEG -EEG system 21 Block diagram

22. • 22 H u m a n bod y te m p e rat u re 2 7 c t o 3 6 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

23. • • • • • Air conditioner business developed recently CFC emission increased Alternative should be found out Peltier effect is being used Beneficial to use because Low maintenance Long life No moving parts Can be used for microchip cooling 23 TEG for Cooling

24. Low power devices such as wrist watches and hearing aids 2 4 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 25 thermic watch by SEIKO

26. Automotive thermoelectric generators TEG in the exhaust of an automobile THERMO ELECTRIC GENERATOR 26

27. 27 Figure 12

28. 28 Thermo Electric Generator stove

29. 29 Thermoelectric Phone Charger

30. Advantages 30 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 1/20 th of a solar cell. Portable power. Less weight than a battery. THERMO ELECTRIC GENERATOR

31. Disadvantages 31 Low efficiency. High cost. High output resistance. Adverse thermal conditions. THERMO ELECTRIC GENERATOR

32. Conclusion 32 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. 3 THERMO ELECTRIC GENERATOR