Authors: Mustafa Kemal Kaymak; Ahmet Duran Sahin
Addresses: Aeronautic and Astronautics Faculty, Meteorology Department, Energy Group, Istanbul Technical University, Istanbul 34469, Turkey. ' Aeronautic and Astronautics Faculty, Meteorology Department, Energy Group, Istanbul Technical University, Istanbul 34469, Turkey
Abstract: The thermodynamic characteristics of solar irradiation in the different layers of atmosphere are investigated from a perspective based on exergy. It is known that the main energy source of photovoltaic (PV) cells, solar power satellites and solar thermal devices is the solar irradiance incident on modules. To evaluate the exergy efficiency of PV cells, therefore, firstly we need the exergy of the total solar irradiation for considered locations. In this paper, firstly changes of temperature and solar irradiation in the vertical structure of the atmosphere would be considered and after that solar exergy values for different altitudes are estimated. Especially on the upper layers of the atmosphere, solar irradiation potential is higher than in the lower levels, but considering, higher temperature gradient between stratosphere and thermosphere causes important heat losses in PVs along with efficiency decreasing. In addition, vertically temperature gradient decreasing in the troposphere causes increasing solar exergy values.
Keywords: atmosphere layers; photovoltaics; solar exergy; solar irradiation; thermodynamics; exergy efficiency; PV cells; photovoltaic cells; temperature changes; heat losses.
International Journal of Exergy, 2011 Vol.9 No.4, pp.389 - 398
Available online: 25 Nov 2011 *Full-text access for editors Access for subscribers Purchase this article Comment on this article