Energy and Exergy Analysis of the Solar Radiation Incident over Iraq

Abstract

Abstract The solar radiation is renewable energy and great useful energy of in Iraq. This paper presents a study to compare the daily solar exergy, daily solar radiation, and daily solar that measured by Iraqi Agro-meteorological network in Baghdad. Then, a comparison between the solar energy and solar radiation in six cities in Iraq (Basra, Najaf, Baghdad, Anbar, Mosul, and Sulaymaniyah). The solar exergy estimated using the model of Nayak and Tiwari, while the solar radiation estimated using linear correlation which represented by (Angstrom correlation). The results showed that there is an agreement between daily solar radiation and daily solar which measured in Baghdad with mean error throughout the whole year from January to December (7.2%, 2.4%, 12.5%, 9.1%, 3.2%, 5.1%, 3.7%, 5.4%, 10.9%, 11.4%, 11.1%, and 3.7%), respectively. While, the daily solar exergy had very good agreement with the daily solar measured in Baghdad with mean error through the same 12-months (1.4%, 9.4%, 6.1%, 2.6%, 10.8%, 1.9%, 3.5%, 1.6%, 4.4%, 5.1%, 5%, and 2.7%), respectively. Also, higher daily solar radiation and daily solar exergy were in Basra, but the lowest was in Mosul. The daily solar exergy was (10.27, 10.09, 10, 10, 9.69, and 9.81 MJ/m2) in Basra, Najaf, Baghdad, Anbar, Mosul and Sulaimaniya, respectively. While, the percentage difference between daily solar radiation and daily solar exergy was (7.09%, 7.04, 7%, 6.99%, 6.96%, and 6.85 %) in Basra, Najaf, Anbar, Baghdad, Mosul and Sulaimaniya, respectively.