Abstract
Electrical energy is an essential factor for economic growth and technological development in the world. The adoption of a different mix of naturally occurring renewable energy sources is one way to diversify, as the need for electrical energy has increased due to the world's growing population. This research focused on five different brands of polycrystalline solar panel (PV- photovoltaic) modules used in solar electrical installations in South Africa and ways to predict their performance yield and cost benefits. The five modules with the same power rating from different manufacturers were named PV1, PV2, PV3, PV4, and PV5, though their tier or grade levels were not stated. The modules were analyzed and compared based on their performances and cost benefits towards an informed and profitable choice by customers.
The results showed that PV1 has an average value between 25-30% power output performance than PV2 during the maximum peak conditions and shows no significant difference during the minimum power output conditions. PV2 on average has around 28-30% and 8-11% more power output than PV3 and PV5 respectively during maximum peak conditions and 27-29% and 7- 9% during minimum conditions, while the average costs of the panels are R295, R260, R170, R150, and R141 for PV4, PV2, PV1, PV5, and PV3 respectively. The Multiple Correlation Regression (R) obtained for PV1, PV2, PV3, PV4, and PV5 through Statistical Regression Analysis (SRA) showed approximately 92.9%, 96.9%, 99.1%, 97.2%, and 77.5% high correlations between the respective panel’s power outputs (Watts) and temperature as against low correlations for cost analysis. Therefore, within the period of study, it was observed that the costs of these modules do not affect their power output performances at given irradiance and ambient temperature. Furthermore, a techno-economic index conducted on the data showed that the modules have the highest indices in the afternoon, while one of the modules has an average of zero in the morning. The indices showed that the fact that a module is expensive might not necessarily mean it will perform best. However, the different tier levels of the PV panels could be responsible for different costs. The costs become important when considering the degradation and characteristics of the PV performances over many years of usage (10-30 years). Tier 1, Tier 2, and Tier 3 PV modules degrade at different rates of 0.30%, 0.50%, and 0.80% respectively over the years, which can be responsible for their different performances. Therefore the long-term benefit of the considered panels used in this study would be according to their costs provided their tier levels are known.