1. Computational Modeling of a Solar Thermoelectric Generator (STEG)
Chukwunyere Ofoegbu
Department of Mechanical and Aerospace Engineering, The Ohio State University
Advisor: Dr. Sandip Mazumder, Funded by: OSU UG Honors Scholarship Program
Research Methods
Conclusions
References
Results
Background
Motivation
1. Kraemer , D., et al. High-performance flat-panel solar thermoelectric generators with
high thermal concentration. Nature Materials, 10, 532-8. 2011 May 1.
2. Tellurex thermoelectric modules, 2010 Tellurex Corporation.
<http://www.tellurex.com/seebeck-faq.pdf>
3. Watzman, S., (2013), Design of a Solar Thermoelectric Generator, Undergraduate
Honors Thesis in Mechanical Engineering, The Ohio State University
 Convert radiant energy from the sun into electricity
 Advantage over PV cells: utilizes full spectrum of the sun’s energy
 Thermoelectric modules serve as the power house in STEGs
 Delayed thermal response allows for continuous power output
 Have great potential for small-scale solar thermal applications
Figure 1: 2D schematic of a STEG unit [1]
 Currently measured efficiency of STEGs are within 4.6% - 5.2%
with thermal concentration [1]
 Low efficiency is attributed to heat losses that occur during
operation, leading to a lower temperature gradient across T.E legs
 Few modeling studies have been performed on solar thermoelectric
generation
Figure 3: Configuration of T.E legs in a thermoelectric module [2]
 Model Geometry
 Simulation Parameters
o 3D coupled transient fluid, thermal, and electric simulation
o Transient simulation performed over 60 minutes
 Temperature Distribution of Transient Simulation
Time = 15
minutes
Time = 60
minutes
Time = 45
minutes
Time = 30
minutes
Time = 60
minutes
Time = 15
minutes
Time = 30
minutes
Time = 45
minutes
 Temperature Distribution Across Thermoelectric Legs
 Voltage Distribution across Thermoelectric Legs for
Different Currents
I = .09A
I = .01A I = .05A
I = .03A
 Validation of Electrical Simulation Results
Figure 2: Cross-sectional view of a thermoelectric module
Max Power =.031 W
 A peak efficiency of .044% was obtained with this numerical simulation
 Primary mode of heat loss is by natural convection to ambient conditions
 Efficiency can be improved operation under vacuum or near vacuum
conditions
 The efficiency of STEGs needs to be improved in order for these
devices to compete with photovoltaic cells
Max Voltage =.78 V
Max Power =.021 W
Max Voltage =.66 V
Objective
 Conduct a detailed computational study on a STEG unit with the goal
of optimizing the device
 Investigate the primary mode of heat loss under terrestrial operations
 Validate the model against experimental data available from a recently
completed UG Honors thesis [3]
Thermoelectric
Legs
Aluminum
Heat Sink
Aluminum
Absorber
Alumina
Layer
Layer of Air
5/8’
’
3/16’’
1.38’’
Thermoelectric legs