Table III: Energy 5-9 September 2011, CCH, Hamburg, Germany FIRST RESULTS OF THE DOUBLE-AXIS SUN TRACKING PV SYSTEM FROM TURKEY Rustu Eke1, Ali Senturk1 and Sener Oktik2 1 Muğla University Faculty of Science and Clean Energy Research & Development Centre 48170 Muğla, Turkey 2 Arıkanlı Holding, Ulus Mahallesi, Öztopuz Caddesi, Leylak Sokak,34340 Ulus, Beşiktaş /İSTANBUL erustu@mu.edu.tr, mutek@mu.edu.tr ABSTRACT In the present study, first results from the double axis sun tracking PV system in Turkey are analyzed. Back contact single crystalline silicon modules are used in PV systems on the tracker units. Two identical PV systems are installed. One is set to a fixed tilt angle and the other tracks the sun in double axis. Measured data of the PV systems are compared with the calculated data and each other. The performance measurements of the PV systems were carried out first. According to the calculations it is found that 70% of 1798 kWh/m2 yearly total energy on horizontal surfaces will be collected in a 6 months period from April to September while the rest 30% is collected during the other 6 months period from October to March. For the double axis tracking surfaces, 65% of energy is calculated as for summer period and 35% for winter period. For 6 months period from April to September electricity fed to grid is calculated to be about 7 MWh for 30° fixed tilt angle for 7.9kWp installed system. Electricity fed to grid during these 6 months is 5.6% more than calculated. It is calculated that 33.8% more energy will be obtained in the double axis sun-tracking system when compared to the fixed system. For 6 months period from April to September electricity fed to grid is calculated to be about 10.27 MWh for double axis tracking 7.9kWp PV system. Electricity fed to grid during these 6 months is 1.6% less than calculated. The daily performances of the PV systems are simulated. These simulations are statistically analyzed and validated. Keywords: Azimuth, Solar Cells, Sun Tracking Double axis tracking 30 degree fixed tilt Difference (%) Total Energy (kWh) 1813.92 1316.05 37.83 kWh/kWp-month 232.55 168.72 kWh/kWp-day 7.75 5.62 Max. Energy (kWh) 3rd May 2010 77.03 52.39 Measured and calculated electricity for 30° fixed tilt angle PV system Measured and calculated electricity for double axis sun-tracking PV system Daily power variation of PV systems in 3rd May 2010. CONCLUSIONS Loss diagrams of fixed and tracking photovoltaic systems. In this study 30⁰ tilt and the double axis sun-tracking system installed in Mugla University main campus is briefly described and six months (from April to September) performances are summarized. This installation gives the advantage of testing back contact mono crystalline silicon PV modules for Mugla climate in Turkey. The electricity yield is measured as 7.0MWh and 10.1MWh for fixed tilt PV system and the PV system on a double axis sun tracker. It is calculated that 33.8% more electricity will be obtained in the double-axis sun-tracking system when compared to the fixed system. For the double axis tracking surfaces, 65% of energy is calculated as for summer period and 35% for winter period. Because of the temperature effect (high operating temperatures in summer lower the power output) calculated energy ratios vary about 5%. Energy rating value for both PV systems are also calculated, measured and compared. It is found that annual energy rating for 30° fixed tilt angle is calculated as 1512kWh/kWp and for the double axis tracking system it is calculated as 2023 kWh/kWp. Approximately 62% of the calculated value for fixed tilt angle six months period from April to September as 938kWh/kWp and 63% of the calculated value for the double axis tracking PV system is measured as 1279kWh/kWp for the same period. There is only a few difference in daily electricity values between PV systems in closed days but in clear sky days total electricity difference is exceeding 50% where monthly difference is calculated between 35-47% for the six months of summer test period. The operating temperature during the selected day for both PV systems reaches up to 62°C at noon time which is 37⁰C above the value of STC and 13⁰C above the value of NOCT. At this high operating temperature the total power output from the inverters is measured about 6900W which corresponds 87% of its installed power. ACKNOWLEDGEMENTS This work was supported by Deutshe Energie Agentur (dena) and Muğla University Scientific Research Projects department and implanted by SUNSET Energietechnik GmbH. REFERENCES [1] California Institute of Technology. Basic research needs for solar energy utilization. Report of the basic energy sciences workshop on solar energy utilization; 2005 April. p. 18-21. [2] Mousazadeh H, Keyhani A, Javadi A, Mobli H, Abrinia K, Sharifi A. Renewable and Sustainable Energy Reviews 2009;13:1800-18. [3] Gay CF, Yerkes JW, Wilson JH. In: Proceedings of the 16th photovoltaic specialists conference. San Diego; September 27-30 1982. p. 1368-71. [4] Abdallah S. Energy Conversion and Management 2004;45:1671-9. [5] Ángel A. Bayod-Rújula, Ana M. Lorente-Lafuente, Fernando Cirez-Oto, Energy 36 (2011) 3148-3158. [6] http://www.dmi.gov.tr/ [7] Huld T, Cebecauer T, Šuri M, Dunlop E. Prog Photovoltaics Res Appl 2010;18(3):183–94. [8] Neville RC. Sol Energy 1978;20:7–11. [9]PVSYST http://www.unige.ch/cuepe/pvsyst/pvsyst/index.htm [10] C. Oguz, MSc Thesis, Muğla University, (1999). [11] R. Eke, S. Ozden, A. Senturk, O.Fleck and S. Oktik, In Proceedings of 25th EUPVSEC, Valencia; 6-10 September 2010. [12]Sunset-Solar datalogger data sheets.