Estimating and Comparing the Exergetic Solar Radiation Values of Various Climate Regions for Solar Energy Utilization

Abstract

Energy resources and their utilization intimately relate to sustainable development. In attaining sustainable development, increasing the energy efficiencies of processes utilizing sustainable energy resources plays an important role. The utilization of renewable energy offers a wide range of exceptional benefits. There is also a link between exergy and sustainable development. Exergy analysis has been widely used in the design, simulation, and performance evaluation of various energy systems as well as renewable energy sources. In this regard, determination of exergy of solar radiation is very crucial for various solar energy-related applications and is based on the relative potential of the maximum energy available from radiation. The efficiency factor limiting the gain of the maximum useful energy from the solar radiation is significantly similar to that of the Carnot efficiency for the heat engines. The main objectives of this study are two-fold, namely, (i) to comprehensively review various solar exergy models used in solar energy-related applications, and (ii) to determine the solar exergetic values for some regions of Saudi Arabia and Turkey, which are taken as two illustrative examples to which various models have been applied and compared. In this regard, the ratios of solar radiation exergy to solar radiation energy (exergy-to-energy ratio) for northeastern Saudi Arabia are calculated to be on average 0.933 for both approaches of Petela and Spanner and 0.950 for Jefer's approach at outside air temperatures between 16.18 and 33.01 ı C. These ratios for Izmir, Turkey are obtained to be on average 0.935 and 0.951 for the same approaches at a temperature range of 15-22 ı C, respectively. The values found using Jefer's approach appear to be 2% larger than the approaches of Petela and Spanner, while those are very close to the value of 0.95 proposed by Nobusawa.

Solar exergy evaluation and empirical model establishment; case study: Iran

“…It should be noted that in the study of ( Alta et al., 2010 ) and ( Arslanoglu, 2016 ) both performed for Turkey, this ratio was found to be 0.93. Also in study of ( Hepbasli and Alsuhaibani, 2014 ) the mean annual exergy to energy ratio for northeastern Saudi Arabia and Izmir in Turkey were obtained 0.933 and 0.935 according to Petela's approach, respectively and 0.950 and 0.951 according to Jefer's approach, respectively. The discrepancies are due to differences associated with the atmospheric and climatic conditions of the mentioned stations compared with those of Iran.…”

“…The actual efficiency of a solar system is the ratio of the work performed by the system divided by the solar radiation energy as ( Alta et al., 2010 ; Hepbasli and Alsuhaibani, 2014 ): …”

“…According to Petela (2003) , such work is equivalent to solar radiation exergy. Therefore, the maximum efficiency is ( Alta et al., 2010 ; Hepbasli and Alsuhaibani, 2014 ): …”

“…( Hepbasli and Alsuhaibani, 2014 ) conducted a study on the estimation and comparison of solar exergy in different climate areas of Turkey and Saudi Arabia. Two major goals were: 1-Comprehensive study of various models of exergy analysis to use in solar systems 2-Determination of solar exergy values for some regions of Turkey and Saudi Arabia.…”

Transition towards sustainable energy production – A review of the progress for solar energy in Saudi Arabia

“…This policy can also save the quantity of fossil fuels (oil and natural gas) available for export, the main source of the Saudi Arabia’s income for its economic development (Cinti, 2011). Solar energy can also be used for desalination projects in Saudi Arabia saving around 1.5 million barrels of oil per day which can reduce the parallel effects of oil price hikes (Hepbasli and Alsuhaibani, 2014). A solar plant with a capacity of 20 MW generates about 200–300 GWh/year, with estimated power plant area of 1.25 km 2 .…”