* Corresponding author: Ü. Yılmaz, Harran University, 63000 Şanlıurfa, Turkey, E-mail: uyilmaz@harran.edu.tr 1 Harran University, 63000 Şanlıurfa, Turkey 2 Faculty of Electrical and Electronics Engineering, Iskenderun Technical University, 31200 İskenderun/Hatay, Turkey 3 Faculty of Electrical and Electronics Engineering, Cukurova University, 01330 Sarıçam/Adana, Turkey Copyright © JES 2017 on-line : journal/esrgroups.org/jes Ünal Yılmaz 1,* , Ömer Türksoy 2 , Turgay İbrikçi 3 Ahmet Teke 3 J. Electrical Systems 13-2 (2017): 255-265 Regular paper                                                   Şı                      !       "                              # $ $ #$$                   #$$ %&   &           Şı           #’#(               Şı           %&) (  )&) ( Keywords: PV panel; MPP; ANN; Cascade-forward backpropagation; Feed-forward Backpropagation Article history: Received 2 March 2017, Accepted 11 May 2017 1. Introduction Increased energy needs with technological developments, threatening global warming and the depletion of fossil fuels have led us to use renewable energy sources. Such as wind energy, geothermal energy, solar energy and so forth [1, 2, 3]. Solar energy has some advantages like to be clean energy, Photovoltaic (PV) panels can convert solar energy to electrical energy directly and also they can produce electrical energy everywhere sunlight exist. The other side PV panels have a few drawbacks like that the power, current and voltage of PV panels are nonlinear they depend on environmental conditions so that variable environment conditions affects efficiency of energy system. Determination of the electrical characteristics and MPPs of PV panels under variable environmental conditions is an important step for efficiency of PV panels and saving energy cost [4, 5]. Şanlıurfa is a region in the southeast of Turkey and annual average sunshine duration is 7.8 hour/day and annual average temperature level is about 17ºC [6]. BLUESUN BSM-230M model Photovoltaic (PV) panel is used in the field study. The inputs of ANN are PV temperature, ambient temperature, Irradiance and outputs are Maximum Power Points, Open Circuit Voltages, Short Circuit Currents, Current and Voltages at MPP, Fill Factors, and Eta % ratio. The installed system is shown in the Figure 1.