Long-Term Reliability Evaluation of Silica-Based Coating with Antireflection Effect for Photovoltaic Modules

Kensuke Nishioka,So Pyay Moe,Yasuyuki Ota

doi:10.3390/coatings9010049

Abstract

Not all sunlight irradiated on the surface of a photovoltaic (PV) module can reach the cells in the PV module. This loss reduces the conversion efficiency of the PV module. The main factors of this loss are the reflection and soiling on the surface of the PV module. With this, it is effective to have both antireflection and antisoiling effects on the surface of PV modules. In this study, the antireflection and antisoiling effects along with the long-term reliability of the silica-based layer easily coated on PV modules were assessed. A silica-based layer with a controlled thickness and refractive index was coated on the surface of a Cu(In,Ga)Se2 PV array. The array was exposed outdoors to assess its effects and reliability. As a result of the coating, the output of the PV array increased by 3.9%. The environment of the test site was relatively clean and the increase was considered to be a result of the antireflection effect. Moreover, it was observed that the effect of the coating was maintained without deterioration after 3.5 years. The coating was also applied to a silicon PV module and an effect similar to that of the CIGS PV module was observed in the silicon PV module.

Highlights

With a rising problem in the field of energy, renewable energy sources that are non-reliant on fossil fuels continue to attract attention
The antireflection and antisoiling effects, and long-term reliability of the silica-based layer coated on PV modules was assessed
A silica-based layer with antireflection and antisoiling effects was coated on the surface of CIGS PV arrays, and the arrays were exposed outdoors to assess the effects and the reliability of the coating

Summary

Introduction

With a rising problem in the field of energy, renewable energy sources that are non-reliant on fossil fuels continue to attract attention. Reflection and soiling on the surface of the PV module, References [3,4,5,6], are among the main factors for this loss. Both must be considered in the developing of high-efficiency PV systems. The cover glass of PV modules reflects approximately 4% of the incident light irradiated to it [7]. Energy losses of the incident light on PV modules occur through the reflection of the air/glass interface due to the difference in the refractive index of the medium [8]. It is relevant to incorporate antireflection and antisoiling effects on the PV module surface to improve the performance of PV systems

Methods

Results

Conclusion