Measurement and validation of polysilicon photovoltaic module degradation rates over five years of field exposure in Oman

Honnurvali Mohamed Shaik,Naren Gupta,Abdul Manan Sheikh,Adnan Kabbani,Keng Goh,Tariq Umar,

doi:10.3934/energy.2021055

Abstract

<abstract> Degradation of PV modules have a severe impact on its power-producing capabilities thus affecting the reliability, performance over the long run. To understand the PV degradation happening under the influence of local environmental conditions a survey was conducted on six polycrystalline silicon-based PV modules over five years. It has been observed that the average degradation rates stood at 1.02%/year at irradiances 800 W/m2 and 0.99%/year at irradiances 600 W/m2, which are almost double the manufacturer proposed values. Upon further investigations, it has been found that discoloration of encapsulant in modules 3, 5, and 6 have been the main factor causing the reduction of the short circuit current (Isc) thus affecting the overall power production capacity of the installed PV system. Considering the amount of time, resources and manpower invested to perform this survey an alternate way of estimating the PV degradation rates is also investigated. The exponential decay factor-based model is adopted to correlate the encapsulant discoloration seen on-site in the form of a mathematical equation to predict the current loss. This loss is defined as the visual loss factor in this paper. Further, the output I-V curves are simulated using MATLAB Simulink-based mathematical model which also integrates visual loss factor (VLF) losses into it. Such simulated I-V curves have shown a good match with the measured I-V curves at the same irradiance with an error less than 3%. Authors anticipate that this modelling approach can open the door for further research in developing algorithms that can simulate the PV degradation rates. </abstract>

Highlights

Sultanate of Oman, one of the countries in the GCC (Gulf Cooperation Council) member countries has set a vision to generate 15% of the total energy production through renewable sources
The site consists of six PV modules which will be termed as PV modules 1,2,3...6 in this paper
Understanding the performance of the PV modules subjected to field exposure plays a crucial role in improving system performance and in the decision-making process in future deployments

Summary

Introduction

Sultanate of Oman, one of the countries in the GCC (Gulf Cooperation Council) member countries has set a vision to generate 15% (around 3GW) of the total energy production through renewable sources. Considering the abundant resource availability and the costcompetitiveness, solar installation is expected to grow by six folds reaching an installed capacity of around 2840 GW by the ten years (2030) [2] Considering such huge investments being made in the PV industry, the accurate estimation of payback time/return on investments plays a crucial role for the stakeholders, researchers, and PV industry-related individuals. The longterm performance (which means at least, 10–20 years) of the PV systems has not been investigated in these environmental conditions This is because the PV installations started to deploy in 2014 only and are currently being under investigation in terms of their reliability and performance over the long run. Degradation rates reported in different parts of the world including Oman are summarized in below Table 1

Methods

Results

Conclusion