Performance of Soiled PV Module Technologies:  Behavior Based on Controverted Parameters
Suellen C.S. Costa1, Antonia Sonia A.C. Diniz1, Sonali Bhaduri2, Lawrence L. Kazmerski1,2,3
1Pontificia Universidade Católica de Minas Gerais (PUC Minas),, Belo Horizonte, Brazil
/2Indian Institute of Technology-Bombay (IIT-B), Mumbai, India
/3RASEI, University of Colorado Boulder, Boulder, CO, United States

The choice of a particular PV technology for a best performance is sometimes based upon a single observation or single operating condition. However, many parameters for electrooptical have opposing or controverted functionalities, such as a wide bandgap oxide having high carrier mobilities or metals possessing high-optical transparencies. In this paper, the choice of appropriate PV technologies for moderate- to harsh-climate conditions is explored based upon controverted parameters of spectral effects and temperature. Specifically, a higher bandgap PV technology (a-Si:H or CdTe) may be higher-temperature choices over lower bandgap candidates (e.g., Si or Cu(In,Ga)Se2). But opposing or controverting this temperature parameter is the spectral effects of the available light. It is reported that soiling or dust tends to absorb more of the lower wavelength light, such that CdTe or a-Si:H would be disadvantaged as the technology for geographical regions where particulate accumulation of module surfaces is a concern. This paper examines these two controverted parameters (spectral effects due to soiling of the module surface and module temperature) to identify regions of “best-of-class” performance for these four common technologies (crystalline Si, CIGS, CdTe, and a-Si:H). Simple modeling is used based upon actual soiling ratios and soiling rates for various geographical regions and the temperature characteristics of these module technologies to investigate specific performances. The spectral effects of the soiling particulates are correlated with the chemistry/composition of the soiling layers and their mass densities to support the conclusions of this paper.
This research project is supported in part by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) in Brasil, under Pesquisador Visitante Especial (PVE) CAPES - Ciência sem Fronteiras, Chamada 09/2014 CAPES, 8881.068091/2014-01.