ABSTRACT
The output power of a Photovoltaic (PV) system is closely related to external environment factors of the installation site, among which, solar radiation is the most significant influence. Therefore, solar radiation conditions is an important reference data to evaluate the initial installation of a PV system and also its long-term operation performance and system maintenance for 30–40 years. If the accuracy of the solar radiation estimation method is too low, solar radiation cannot be accurately predicted, and the PV system’s power generation investment benefit may be underestimated. In this paper, the Inverse Distance Weighting (IDW) algorithm is used to build a solar radiation estimation model. A model was established based on the daily solar radiation monitoring data at 10 sites in Tainan City, and the model was verified by data from two sites: Liujia Wastewater Treatment Plant and Wu Wang Elementary School. The verification results show that the Mean Absolute Percentage Error (MAPE) of solar radiation estimation is less than 10%, achieving excellent prediction accuracy. The research also completes the solar radiation map of Tainan City, Taiwan as an important reference for the evaluation of PV system installation and operation and maintenance.
