Optical Constants of UV Transparent EVA and the Impact on the PV Module Output Power under Realistic Irradiation

Abstract We measure and discuss the complex refractive index of conventional ethylene vinyl acetate (EVA) and an EVA with enhanced UV-transmission based on spectroscopic ellipsometry, transmission and reflection measurements over the wavelength range from 300-1200 nm. Ray tracing of entire solar cell modules using this optical data predicts a 1.3% increase in short circuit current density (Jsc) at standard test conditions for EVA with enhanced UV transmission. This is in good agreement with laboratory experiments of test modules that result in a 1.4% increase in Jsc by using a UV transparent instead of a conventional EVA. Further, ray tracing simulations with realistic irradiation conditions with respect to angular and spectral distribution reveal an even larger Jsc increase of 1.9% in the yearly average. This increase is largest in the summer months with an increase of up to 2.3%.

[1]  Karsten Bothe,et al.  Increased Light Harvesting by Structured Cell Interconnection Ribbons: An Optical Ray Tracing Study Using a Realistic Daylight Model☆ , 2016 .

[2]  G. Kinsey,et al.  Impact of High Light Transmission EVA-Based Encapsulant on the Performance of PV Modules , 2012 .

[3]  J. Betcke,et al.  Solar spectral irradiance derived from satellite data: A tool to improve thin film PV performance estimations? , 2013 .

[4]  335Watt world record P-type mono-crystalline module with 20.6 % efficiency PERC solar cells , 2015, 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC).

[5]  G. Hahn.  Status of Selective Emitter Technology , 2010 .

[6]  Carsten Schinke,et al.  Measurement of the Optical Constants of Soda-Lime Glasses in Dependence of Iron Content and Modeling of Iron-Related Power Losses in Crystalline Si Solar Cell Modules , 2016, IEEE Journal of Photovoltaics.

[7]  Matthias Winter,et al.  Application of a New Ray Tracing Framework to the Analysis of Extended Regions in Si Solar Cell Modules , 2013 .

[8]  Siew Yee Lim,et al.  Uncertainty analysis for the coefficient of band-to-band absorption of crystalline silicon , 2015 .

[9]  Karsten Bothe,et al.  Optimizing the Solar Cell Front Side Metallization and the Cell Interconnection for High Module Power Output , 2016 .

[10]  S. Areerat,et al.  Effects of Organic Peroxides on the Curing Behavior of EVA Encapsulant Resin , 2012 .

[11]  Armin G. Aberle,et al.  Optimised antireflection coatings for planar silicon solar cells using remote PECVD silicon nitride and porous silicon dioxide , 1999 .

[12]  Bastian Zinßer.  Jahresenergieerträge unterschiedlicher Photovoltaik-Technologien bei verschiedenen klimatischen Bedingungen , 2010 .

[13]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[14]  M. Vogt,et al.  Development of physical models for the simulation of optical properties of solar cell modules , 2015 .

[15]  Harry Wirth,et al.  Unified methodology for determining CTM ratios: Systematic prediction of module power☆ , 2014 .

[16]  Nick E. Powell,et al.  An optical comparison of silicone and EVA encapsulants for conventional silicon PV modules: A ray-tracing study , 2009, 2009 34th IEEE Photovoltaic Specialists Conference (PVSC).

[17]  Taizo Sasaki,et al.  Self-consistency and sum-rule tests in the Kramers-Kronig analysis of optical data: Applications to aluminum , 1980 .

[18]  Thomas R. Betts,et al.  Investigation of photovoltaic device operation under varying spectral conditions , 2004 .

[19]  Method for quantifying optical parasitic absorptance loss of glass and encapsulant materials of silicon wafer based photovoltaic modules , 2012 .

[20]  Matthias Winter,et al.  Combining structures on different length scales in ray tracing: analysis of optical losses in solar cell modules , 2014, Numerical Simulation of Optoelectronic Devices, 2014.