Analysis of Ankara's Exposure to Solar Radiation: Evaluation of Distributional Parameters Using Long-Term Hourly Measured Global Solar Radiation Data


Abstract: Turkey is becoming more dependent on imported primary energy to meet its increasing energy demand. The ratio of indigenous primary energy production to primary energy consumption is decreasing noticeably. Therefore, it is of great importance for Turkey to make use of its indigenous energy resources more effectively, including its solar energy potential. Solar energy is one of the most abundant energy resources in the country and should be utilized at the maximum level possible. The global solar radiation incident on a horizontal surface and daily sunshine hours are measured in Turkey by many recording stations of the Turkish State Meteorological Service (DME). According to these measurements, the yearly average daily solar radiation was 3.6 kWh/m^2, with a yearly total radiation period of over 2640 h. However, in recent years it has widely been acknowledged that the actual solar energy potential of Turkey is more than was previously thought. In the present article, the solar radiation data on Ankara (lat 39.95 °N, long 32.88 °E; elevation: 891 m) are analyzed based on 6 years of global solar radiation data measured on a horizontal surface by the DME. The distributional solar radiation parameters are derived from the available data and analyzed. The available solar radiation data on a horizontal surface are converted to that of various tilt angles and the yearly and monthly optimum tilt angles are determined.

Keywords: Renewable energy, Solar radiation, Optimal tilt angle, Clearness index

Full Text: PDF