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Title: Soiling and cleaning: Initial observations from 5-year photovoltaic glass coating durability study

Journal Article · · Solar Energy Materials and Solar Cells
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  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
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The contamination of solar photovoltaic cover glass can significantly reduce the transmittance of light to the surface of the photovoltaic cell, reducing the module's power output. The solar industry has been developing antireflection (AR) and antisoiling (AS) surface coatings to enhance light transmittance and mitigate the impacts of soiling. Although uncoated glass has been field tested for decades, minimal data exist to demonstrate the durability of AR and AS coatings against abrasion and surface erosion, including from: natural weathering, airborne sand, and industry cleaning practices. Coupons 75 mm square of varying types have been field-deployed to gather long-term data on coating durability; the initial results are presented here after 1 year of outdoor exposure near Sacramento, California. Duplicate sets of coupons were cleaned monthly per four different cleaning practices. All coupons demonstrated inorganic soiling as well as microscale biological contamination, regardless of cleaning method. Additionally, full-sized, field-aged modules from other areas of the world presented with similar types of contamination as the field-aged coupons; micrographs and results from genomic sequencing of this contamination are included here. Optical microscopy, scanning electron microscopy, atomic force microscopy/energy-dispersive spectroscopy, surface roughness, transmittance, and surface energy analysis of representative specimens and cleaning practices are presented.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
Grant/Contract Number:
AC36-08GO28308; 30311
OSTI ID:
1458821
Alternate ID(s):
OSTI ID: 1591687
Report Number(s):
NREL/JA-5J00-71853
Journal Information:
Solar Energy Materials and Solar Cells, Vol. 185, Issue C; ISSN 0927-0248
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 39 works
Citation information provided by
Web of Science

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Cited By (4)

Modelling photovoltaic soiling losses through optical characterization journal January 2020
Are Nano-Composite Coatings the Key for Photovoltaic Panel Self-Maintenance: An Experimental Evaluation journal December 2018
Soiling of Photovoltaic Modules: Comparing between Two Distinct Locations within the Framework of Developing the Photovoltaic Soiling Index (PVSI) journal August 2019
Hydrophilic and Superhydrophilic Self-Cleaning Coatings by Morphologically Varying ZnO Microstructures for Photovoltaic and Glazing Applications journal January 2020

Figures / Tables (20)

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14 SOLAR ENERGY
47 OTHER INSTRUMENTATION
coatings
durability
fungi
optical performance
particulate matter
soiling