A literature review on estimating of PV-array hourly power under cloudy weather conditions

The capacity of installed photovoltaic cells (PVs) has been remarkably increased globally over past few decades. In addition, changing cloud cover (Oktas-scale) is an important component that influences on solar radiation hourly and plays a key role in electrical output power of PVs. However, it is necessary for electrical utilities to use a powerful model in order to forecast PV power systems on electrical networks. Thus, forecasting power output of PV systems increase the quality of modern power systems. This paper presents a comprehensive review on short term forecasting of solar PV power output in modern electrical networks. Additionally, a new model based on hourly measurements has been proposed in this research and was reported during the past 20 years in Sanandaj (Applied Research Center of Kurdistan Weather), located in west of Iran (14°.35′N, 46°.35′E). The results show that the possibility of changing hourly and PV output power estimate based on Oktas analysis have been calculated with minimum fault.