Energy Performance of Renewable Technologies: LR of PV Panels With Analysis of Their Efficiency in Relation to Internal and External Factors

The application of renewable technologies and in particular solar photovoltaic (PV) market has grown rapidly throughout the past 15 years worldwide. Despite the market growth, one of the main factors limiting the application of PV panels is the degradation issue or power decline over time, highlighting the need of further studies on degradation rate and reliability assessment to predict panel life expectancy, economic values and financial risks. PV panels behave differently under certain conditions, and energy production of panels varies not only with the capacity of the system but also with the type of modules in panel. Researchers have also studied how different modules/panels perform for long periods of time, when exposed out in the field. In this article, a literature review of PV panel performance over time was accumulated from different resources to identify the sources of uncertainty about their performance, reliability, and durability under internal and external factors. The results show that both the internal factors such as cell interconnect breakages alongside external ones such as the sunlight, temperature change or dirt accumulation were determined to be the primary causes for the power loss and reduced energy generation in the PV panels and highlights further research in this area.