Modeling Solar Energy Potential In Turkey

Since the Industrialization revolution, atmospheric CO 2 concentration has been increased from 280 to 400 ppm due to mainly caused fossil fuel uses in the energy sector. However, small portion of the incoming solar energy into the world is sufficient to meet human needs. For this reason nowadays to use renewable energy sources such as solar energy is very important to protect atmosphere. Geographic variables are measured at certain points, and prediction map for the entire area is been obtained by some spatial interpolation methods. Spatial distribution of geographic data can be obtained only from this data and also prediction map can be obtained by using secondary variables which have spatial relationship with the measured values (Bostan, P.A., et al, 2007) Geographically Weighted Regression (GWR) and Co-kriging methods were applied in the modelling of radiation. GWR is the multi-faceted approach to the analysis of spatial data. GWR opens a window through the data set to calculate local r 2 (Laffan, 1999). Co-kriging is an extension of ordinary kriging method which takes into account the spatial cross-validation between two or more data. In the modeling of spatial interpolation of radiation data, aspect, latitude, relative humidity and cloudiness were used as secondary variable. Best results were obtained with the cloudiness and relative humidity parameters. Simple linear models generally are been solved by ordinary least square method is given below formula: P= C1+C2+e where; P= Radiation (KWh/m²) C1= solar radiation parameters change with the humidity C2= solar radiation parameters change with the cloud cover e= error term Co-kriging and GWR model results were compared by the lowest RMSE and higher r² values obtained in the model. Because of the RMSE is smaller and r 2 is grater than the Co-kriging result, GWR tool is been selected for modeling solar energy potential in Turkey. According to model result, southern parts of Izmir-Igdir line, have over 1500 KWh/m²/Year radiation potential and is considered as optimum area for the photovoltaic installation.