Output Power Forecasting for 6kW Thin-Film PV System using Response Surface Methodology

Photovoltaic (PV) system is an attractive option for the energy sector nowadays due to its renewable nature. However, because of the unpredictable nature of weather, it is difficult to determine the generation of the PV system beforehand. Thus, forecasting is essential for the determination of Return of Investment (ROI) of a newly installed PV system. This paper proposes the application of Response Surface Methodology (RSM) to forecast the output power of the 6kW thin-film PV System. Three environmental elements are used; irradiance, module temperature, and ambient temperature. For that, MATLAB RStool which is consisting of four models; multiple linear regression (MLR), interactions, pure quadratic, and full quadratic was used. The 5 minutes sampling size data weather station from the year 2014 of the 3-phase three environmental elements and output power of 6kW thin-film was recorded and used. Whereas, yearly 2015 data of the aforementioned elements were used for validation. Forecasting performance measures such as the determination of coefficient (R2) method and root mean square error (RMSE) approach are presented. The results indicated that a full quadratic model provides the best forecasting model with a resulting R2 value of 0.9981 and gives the least amount of RMSE which is 18.74.