Solar thermoelectric generators (STEGs) convert solar energy to electricity. The solar energy is first used to heat an absorber plate that serves as the high temperature reservoir. Power is generated by connecting the hot reservoir and cold (ambient) reservoirs with a pair of p- and n-doped thermoelectric legs. Experimental studies have shown that the efficiency of a STEG can reach values of about 5% if the entire setup is placed in near-vacuum conditions. However, under atmospheric conditions, the efficiency decreases by more than an order of magnitude, presumably due to heat loss from the absorber plate by natural convection. A coupled fluid–thermal–electric three-dimensional computational model of a STEG is developed with the objective of understanding the various loss mechanisms that contribute to its poor efficiency. The governing equations of mass, momentum, energy, and electric current, with the inclusion of thermoelectric effects, are solved on a mesh with 60,900 cells, and the power generated by the device is predicted. The computational model predicts a temperature difference (ΔT) of 16.5 K, as opposed to the experimentally measured value of 15 K. This corresponds to a peak power of 0.031 W as opposed to the experimentally measured peak power of 0.021 W. When only radiative losses are considered (i.e., perfect vacuum), the ΔT increases drastically to 131.1 K, resulting in peak power of 1.43 W. The predicted peak efficiency of the device was found to be 0.088% as opposed to the measured value of 0.058%.

References

References
1.
Goldsmid
,
H. J.
,
Giutronich
,
J. E.
, and
Kaila
,
M. M.
,
1979
, “
Solar Thermoelectric Generation Using Bismuth Telluride Alloys
,”
Sol. Energy
,
24
(5), pp.
435
440
.10.1016/0038-092X(80)90311-4
2.
Kraemer
,
D.
,
Poudel
,
B.
,
Feng
,
H.-P.
,
Caylor
,
J. C.
,
Yu
,
B.
,
Yan
,
X.
,
Ma
,
Y.
,
Wang
,
X.
,
Wang
,
D.
,
Muto
,
A.
,
McEnaney
,
K.
,
Chiesa
,
M.
,
Ren
,
Z.
, and
Chen
,
G.
,
2011
, “
High-Performance Flat-Panel Solar Thermoelectric Generators With High Thermal Concentration
,”
Nat. Mater.
,
10
, pp.
532
538
.10.1038/nmat3013
3.
Watzman
,
S.
,
2013
, “
Design of a Solar Thermoelectric Generator
,” Undergraduate Honors Thesis in Mechanical Engineering, The Ohio State University, Columbus, OH.
4.
Chen
,
G.
,
2011
, “
Theoretical Efficiency of Solar Thermoelectric Energy Generators
,”
J. Appl. Phys.
,
109
(
10
), p.
104908
.10.1063/1.3583182
5.
Goldsmid
,
H. J.
,
2010
,
Introduction to Thermoelectricity
(Springer Series in Material Science),
Springer
,
New York
.10.1007/978-3-642-00716-3
6.
Ali
,
S. A.
, and
Mazumder
,
S.
,
2013
, “
Computational Study of Transverse Peltier Coolers for Low Temperature Applications
,”
Int. J. Heat Mass Transfer
,
62
, pp.
373
381
.10.1016/j.ijheatmasstransfer.2013.03.018
7.
Whitaker
,
S.
,
1983
,
Fundamental Principles of Heat Transfer
,
Krieger Publishing Company
,
Malabar, FL
.
8.
Incropera
,
F. P.
,
Dewitt
,
D. P.
,
Bergman
,
T. L.
, and
Lavine
,
A. S.
,
2006
,
Introduction to Heat Transfer
,
6th ed.
,
Wiley
,
New York
.
9.
Lynch
,
C. T.
, ed.,
1975
,
CRC Handbook of Material Science, Volume III: Nonmetallic Materials and Applications
,
CRC Press
,
Boca Raton, FL
.
10.
National Oceanic, Atmospheric Administration Solar Calculator, “Solar Position Calculator,” http://www.esrl.noaa.gov/gmd/grad/solcalc/azel.html
11.
Modest
,
M. F.
,
2013
,
Radiative Heat Transfer
,
3rd ed.
,
Academic Press
,
San Diego, CA
.
12.
Bierschenk
,
J. L.
, and
Burke
,
E. J.
,
1990
, “
Thermoelectric Cooler
,” U.S. Patent No. 4922822.
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