Linking satellite imagery to bright sunshine hours for the estimation of global solar irradiation


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, Türkiye

Tezin Onay Tarihi: 2013

Öğrenci: SELMİN ENER RUŞEN

Danışman: BÜLENT GÜLTEKİN AKINOĞLU

Özet:

This thesis is on the estimation models for the daily global solar irradiation on a horizontal surface at the surface of the Earth. New approaches are developed and applied to 15 locations of Turkey and Germany. The main idea in developing the new models is to link the surface data to satellite imagery. Totally three new modeling approaches are developed and tested. Surface data of daily bright sunshine hours (s) and cloud index (n) values derived from satellite images are the main input parameters. In the first approach, monthly coefficients of Angström linear relation between daily solar irradiation and daily bright sunshine hours are used to replace the clear sky irradiance calculations of HELIOSAT model. In the second approach new correlations are obtained between daily bright sunshine hours (s) and cloud index (n). Last model that is developed uses a new correlation expression between daily solar irradiation and daily data of s and n and this expression is derived using a physical consideration. The performances of the proposed models are tested against conventional methods (mainly, satellite-based HELIOSAT and ground-based linear Angström-Prescott type). The results show that the use of sunshine duration together with the cloud index is quite satisfactory in the estimations of daily global solar irradiation. The accuracy of estimations of the combined models is considerably higher than the conventional approaches. Therefore, we propose to use the new approaches to estimate daily global irradiation whenever the data of bright sunshine hours is available for the location of interest or a nearby station. In addition, for a point on the earth surface, depending on the data in hand, suitable and most accurate models of estimations are proposed for that point.