Repository logo
 

Investigating the suitability of existing commercial hydrophobic coatings for soiling mitigation in the photovoltaic industry

Date

2019

Authors

Strauss, Ben, author
Barth, Kurt, advisor
Sampath, Walajabad, committee member
Sites, James, committee member

Journal Title

Journal ISSN

Volume Title

Abstract

The global production of solar power has been increasing approximately 40% per year for the last two decades, making solar one of the quickest growing renewable energy technologies. Estimated to increase 14-fold by the year 2040, solar photovoltaic (PV) power will become a major source of electricity. Soiling, the build-up of dust and debris on the surface of a solar module, is the third largest contributor to losses in solar power output. Decreases in solar module energy production of 20-30% have been observed in arid-desert climates, regions where sunlight is most intense and abundant. Current soiling mitigation techniques involve some type of mechanical cleaning process, either manual or automated, which can be highly water, time, and cost intensive. A potentially beneficial option to reducing PV soiling involves the use of anti-soiling coatings. A number of studies have previously examined the anti-soiling properties of various hydrophobic (water-fearing) and hydrophilic (water-loving) coatings. Though studies are ongoing, research generally shows hydrophobic coatings have an advantage over hydrophilic coatings due to lower dust adhesion forces and water-repellency properties. However, existing research efforts have not conclusively shown that hydrophobic coatings can survive the harsh environmental conditions experienced by a solar module during its lifetime. Anti-soiling research on existing commercial hydrophobic coatings is also minimal. Therefore, this research aims to understand the viability of using existing hydrophobic coatings to mitigate soiling losses seen in the PV industry. A group of hydrophobic coatings were obtained from various sectors of industry, including surface refinement, electronics, ophthalmic, and automotive. An initial screening procedure, designed to characterize the hydrophobic properties of the obtained coatings, was then implemented to identify a group of candidate coatings for this study. An accelerated durability testing procedure, designed specifically for hydrophobic coatings on solar cover glass, was used to identify degradation mechanisms of the candidate coatings in the presence of environmental stressors. Utilizing a custom-built soiling chamber and various dust removal apparatuses, a testing methodology was developed to understand the anti-soiling properties of the coatings. Finally, using an outdoor solar test array, comparative tracking of coated and uncoated modules was performed over an extended period of time. Through durability and anti-soiling experimentation, results from this work led to the identification of a single commercially available hydrophobic coating that demonstrates strong potential for anti-soiling applications in PV.

Description

Rights Access

Subject

coating
photovoltaic
water contact angle
hydrophobic
anti-soiling
solar modules

Citation

Associated Publications