The efficiency of a secondary optical element (SOE) is often questioned when a real high concentrating photovoltaic (HCPV) module is considered. Three years ago Opsun Technologies Inc. introduced a new type of SOE, which increased significantly the acceptance angle of the HCPV module close to the limits predicted theoretically (1). Indeed, introducing a SOE into a HCPV module enables the increase of its acceptance angle. Furthermore, the SOE homogenizes the concentrated sun light beam’s profile, which leads to an improvement of the fill factor. However, the opposite input side of the SOE introduces an additional surface, causing optical losses due to Fresnel reflections. This issue added to the cost of the SOE, discards its benefic properties. Thus, eliminating or minimizing Fresnel reflection could transform the SOE into a powerful tool to boost significantly the efficiency of the HCPV module. Silicon dioxide (SiO2) nanoparticles, obtained by sol-gel technique, were used to create an antireflective coating (ARC) for the use in a high concentrating photovoltaic (HCPV) device. These ARCs have shown a transmission increase from 92% up to 99% when deposited on glass substrates. The introduction of these same ARCs, with different optical paths, in the HCPV system has shown an overall power increase with strong dependence of the HCPV module performance (based on triple junction solar cells) upon the different ARC transmission spectra. In the present work we demonstrate a combination leading to almost 12% power increase in the HCPV. Indeed, a drastic peak power increase is observed here, due to the homogenization of the concentrated sun beam by the SOE and to the incorporation of a cost effective nanoparticle based anti-reflection coating (ARC) that eliminates the Fresnel reflections.

1.
How to increase the efficiency of a high concentrating PV (HCPV) by increasing the acceptance angle to ±3.2°.
A.
Yavrian
, et al, et al.
2013
,
9TH International Conference on Concentrator Photovoltaic Systems: CPV-9
,
AIP Conference proceedings
, Vol.
1556
, pp.
197
200
.
2.
Thermal phase change actuator for self-tracking solar concetration.
E.J.
Tremblay
,
D.
Loterie
and
C.
moser
. S6,
2012
,
Optics Express
, Vol.
20
, p.
174632
.
3.
40% efficent metamorphic GaInP/GaInAs/Ge multijunction solar cells.
R.R.
King
, et al, et al.
90
,
2007
,
Applied Physics Letters
, pp.
183516
-.
4.
Photovoltaic solar cells: An overview of state-of-the-art cell development and environemental issues.
R.W.
Miles
,
K.M.
Hynes
and
I.
Forbes
.
51
,
2005
,
Elsevier-Progress in Crystal Growth and Characterization of Materials
, pp.
1
42
.
5.
Photovoltaics: A Review of Cell and Module Technologies.
L.L.
Kazmerski
. 1/2,
1997
,
Elsevier-Renewable and Sustainable Energy Reviews
, Vol.
1
, pp.
71
170
.
6.
Efficency calculations of thin-film GaAs solar cells on Si substrates.
M.
Yamaguchi
and
C.
Amano
.
58
,
1985
,
Journal of Applied Physics
, p.
3601
.
7.
Cell Efficiency Dependence on Solar Incidence Angle.
Ch.
Seshan
.
2010
,
IEEE.
8.
A.
Luque
.
Solar Cells and Optics for Photovoltaic Concentration.
s.l. :
The Adam Higler series on Optics and Optoelectronics
,
1989
.
9.
P.
Perez-Higueras
,
P.
Fernandez
and
F.
Eduardo
.
High Concentrator Photovoltaics Fundamentals, Engineering and Power Plants
. [ed.]
Springer
.
2015
. pp.
9
37
.
10.
K.
Shanks
,
S.
Senthilarasu
and
T.K.
Mallick
.
High Concentrator Photovoltaics-Fundamentals, Engineering and Power Plants
. [ed.]
P.
Pérez-Higueras
and
E.F.
Fernandez
.
Cornwall
:
Springer International Publishing Switzerland
,
2015
. pp.
85
147
.
11.
H.A.
Macleaod
.
Thin Film Optical Filters.
s.l. :
Taylor & Francis Book
,
2010
.
12.
R.
Willey
,
Ronald
.
Practical Design and Production of Optical Thin Films
. s.l. :
Marcel Dekker, Inc.
,
2002
.
13.
Single-layer, gradient refractive index antireflection films effective from 0.35 to 2.5µ.
J.
Minot
,
Michael
.
6
,
1976
,
J.Opt.Soc.Am.
, Vol.
66
.
14.
L.C.
Klein
.
Sol-Gel Technologiy for Thin Films, Fibers, Preforms, Electronics, and Speciality Shapes
. s.l. :
Noyes Publications
,
1988
. pp.
80
109
.
15.
Antireflecting Coatings for Glass Based on Monolayers of Amorphous Silica Nanoparticles.
S.V.
Es’kin
,
I.D.
Kosobudskii
and
A.B.
Zhimalov
. 4,
2013
,
Pleiades Publishing-Glass Physics and Chemistry
, Vol.
39
, pp.
409
413
.
16.
Hollow Silica Nanoparticles in UV-Visible Antrireflection Coatings for Poly(methyl methacrylate) Substrates.
Yi
Du
, et al, et al.
7
,
2010
,
ACS Nano
, Vol.
4
.
17.
R.
Gilbert
, et al, et al.
Adiabatic secondary optics for solar concentrators used in concentrated photovoltaic systems. EP2984751 A1
2015
.
18.
Understanding causes and effects of non-uniform light distributions on multi-junction solar cells: procedures for estimating efficiency losses.
R.
Herrero
, et al, et al.
2015
,
International Conference on Concentrator Photovoltaic Systems (CPV-11)
,
AIP Conference Proceedings
1679
.
19.
Non-uniform illumination in concentrating solar cells.
H.
Baig
,
K.
Heasman
and
T.K.
Mallick
.
16
,
2012
,
Ren. and Sust. Ener. Rev.
, pp.
5890
5907
.
20.
Subwavelength-structured antireflective surfaces on glass. 
A.
Gombert
, et al, et al.
351
,
1999
,
Elsevier
, Vol.
Thin Solid Films
, pp.
73
78
.
21.
C.A.
Bennett
.
Principles of Physical Optics
. s.l. :
John Wiley & Sons, Inc.
,
2008
.
22.
World Energy Recources: Solar.
2013
.
23.
Durability of Fresnel lenses: A review specific to the concentrating photovoltaic application.
D.C.
Miller
and
S.R.
Kurtz
.
95
,
2011
,
Solar Energy Materials and Solad Cells
, pp.
2037
2068
.
24.
Will we exceed 50% efficiency in photovoltaics?
A.
Luque
.
031001
,
2011
,
Jour.Appl.Phys.
, Vol.
110
.
25.
Comparative analysis of different secondary optical elements for aspheric primary lenses.
M.
Victoria
, et al, et al.
8
,
2011
,
Opt. Express
, Vol.
17
.
26.
Nanophase-Separated Polymer Films as High-Performance Antrireflection Coatings.
S.
Walheim
, et al, et al.
1999
,
Science
, Vol.
283
.
27.
M.
Hosokawa
, et al, et al.
Nanoparticle Technology Handbook
. s.l. :
Elsevier
,
2007
. pp.
250
255
.
28.
Photovoltaic Principle.
M.A.
Green
.
2012
,
Physica E
, Vol.
14
.
29.
Limiting efficency of silicone solar cells.
T.
Tiedje
, et al, et al.
711
716
,
1984
,
IEEE Trans.Electron Devices
, Vols. ED-
31
.
30.
A. Messenger
,
Roger
and
Jerry
Ventre
.
Photovoltaic Systems Engineering.
s.l. :
CRC Press Taylor&Francis Group
,
2010
.
31.
III-V multijunction solar cells for concentrating photovoltaics.
H.
Cotal
,
Ch.
Fetzer
and
J.
Boisvert
.
2009
,
RSC - Energy Environ.Sci.
, Vol.
2
, pp.
174
192
.
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