1. Thermoelectric Energy Conversion Roberto Dimaliwat, Galena Park High School Galena Park ISD Professor/mentor Choongho Yu, PH.D Mechanical Engineering Dept. Texas A & M University Liang Yin, Graduate Research Assistant

2. ZT= S² σT/k Thermoelectric Energy Conversion
Thermoelectric devices use “bulk materials”
with low figure of merit, ZT (efficiency)
ZT= S² σT/k
Study of the electrical and thermal
characteristics of nanowires,
The objective is to find out whether the
nanowires can replace bulk materials, to
produce devices with high ZT.
The higher the ZT, the higher the efficiency
T = average temperature
σ= electrical conductivity
S= Seebeck coefficient
k= thermal conductivity

3. Results SiGe nanowires have lower thermal conductivity
than bulk materials.
As the nanowires get
smaller, the thermal
conductivity lessens.
electrical conductance
tends to be constant
with temperature change,
thus the possible
efficiency improvement
ZT= S² σT/k
Results

4. Physics and Chemistry TEKS/TAKS
Physics TEKS 7B – methods of heat energy transfer.
Physics TEKS 5D – conservation of energy &momentum.
Physics TEKS 6E – design and analyze electrical circuits
Physics TEKS 7A – laws of thermodynamics.
Chemistry TEKS 5A – changes in matter, the nature of
charge, and the forms of energy.
Chemistry TEKS 6A – properties of subatomic particles
TAKS Objectives 4 & 5

5. Hook

6. The Class Project: Energy Conversion and Conservation
Day 1:
1. Hook: Get responses and write on board
2. Do the Pre Test.
3. A short PPT on energy, the different kinds, conservation and transformation using mechanical energy as an example.
4. Discuss the experiment and do parts A (see attached).
Days 2and 3.
1. Do Part B and C and students to finalize data and graphs
and write the report.
2. Answer Part D. (Questions) See attached.
Days 4 and 5.
1. Discuss the lab results.
2. Problem Solving WS
3. Discuss Liang’s slide
4. Post Test

7. Experiment Set up
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8. The experiment (10 groups of 2 to 3 students per group)
Objective: To measure how the difference in temperature varies with the voltage generated in a thermoelectric module.
Materials (per group)
1 Peltier module
1 clip
2 aluminum plates
1 motor with fan blade
2 transparent plastic containers
Hot plate
Ice cold water
Voltmeter
2 Thermometers

9. Part A
1. Place the module between the 2 aluminum plates and
secure it with the clip.
2. Connect the wires of the module to the wires of the
motor.
3. Place the motor on top of the assembly and attach the
fan blade
4. Pour hot water on one of the plastic containers and ice
cold water on the other one.
5. Place the containers side by side and dip the aluminum
plates, with one side on the cold water and the other
side on the hot water.
6. Rotate the fan and observe what happens. Record your
observation

10. 1. Turn on the hot plate and heat about 500ml of water
Part B
1. Turn on the hot plate and heat about 500ml of water
2. Remove the assembly from the water.
3. Remove the motor/fan connection.
4. Replace the connection with a voltmeter.
5. Empty the plastic containers and place the assembly in the
containers just like in Part 1.
6. Put ice cold water in one container and hot in the other.
7. Measure the temperatures on both and record.
8. Measure the voltage on the voltmeter and record.
9. Replace the hot water with hotter water from the hot plate .
10. Measure the temperature and the voltage
11. Repeat the process with different temperatures for about 5
times.
12. Record and graph your data.

11. Part C. Is the process reversible?
1. Using the same materials, design an experiment to
check whether the process is reversible.
2. What other materials do you need? List them down and
justify why you need them for.
3. Present the experiment setup and procedures to your
teacher for approval. Include the list of additional
materials you would need.
4. When you get approval, perform the experiment and
gather your data.
5. Analyze your data and write out your report.
6. What are some possible uses of the module and what
possible applications can the concept of thermoelectric
energy conversion have in your life?

12. Answer the following questions:
Part D. Post Lab Assessment
Answer the following questions:
What did you observe on the fan when the assembly is placed in the water bath? __________________________________________________________
Explain in terms of energy, what is happening?_________________________
________________________________________________________________
3. Explain your data for Part 2. ________________________________________
4. Explain the graph. ________________________________________________
5. Compute for the slope of the graph ___________________________________
Is the process reversible? Explain your answer ________________________________________________________________

13. Assessment (Pre and Post)
Sample Questions:
1. In thermoelectric energy conversion, as the temperature difference increases, the voltage
a) stays the same
b) decreases
c) increases
d) decreases exponentially
2. The conservation of energy states that
a) energy cannot be created nor destroyed
b) can be transformed from one kind to another
c) total energy in a closed system is constant
d) all of the above

14. Acknowledgements E3 Team Choongho Yu, Ph.D
Mechanical Engineering Dept ,TAMU
Liang Yin, Graduate Assistant
National Science Foundation
Nuclear Power Institute
Texas Workforce Commission
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