Turkey is located between latitudes 36° N and 42° N and longitudes 26° E and 45° E (Fig. 6.4) It has significant solar energy potential especially in the southern parts including the Mediterranean region. Twenty eight global solar irradiation and sunshine duration measurement stations scattered all over the country are considered for regionalization studies in this chapter (see Fig. 6.4). At each station, daily records are available concurrently for 12 or 11 years, including 1993.
Monthly mean values of solar irradiation and sunshine duration for 11 year are used in calculation; hence each station has 132 monthly mean data. All data are measured with classical actinographs and sunshine duration recorders by State Meteorological Service, which is a member of ECMWF (DMI 2005). Detailed calculations and presentations are provided only for three sites as Adana, Ankara and Istanbul.
Adana is located in the south Turkey, where Mediterranean Sea effects occur with moderate, severe and extreme drought magnitudes at high level sunshine duration and around high solar irradiation values in this region. These extreme values show that sunshine duration is more effective in the area than solar irradiation. In this area, almost in each day of the year, water is heated with solar collectors and hence solar power plants can be built in the Mediterranean areas.
Ankara is located in the central part of Turkey where there are variations depending on the continental climate effects due to highest summer month topographic condition effects on the rainfall occurrences. Generally, in this semi-arid region, moderate and severe droughts many occur due to occasional effects, which rise to high level degree at this region.
Istanbul has both continental and maritime climatic effects. It is located in northwestern part of Turkey. Due to maritime effect cloud amounts are high and sunshine duration values are lower than southern and central regions of Turkey (Sen and Sahin 1998; Saylan et al. 2002).
Fig. 6.4 Station locations in Turkey