• Energy Research

AbstractThe production of electricity from solar radiation is a direct process. Solar energy is not very dense, it is necessary to concentrate it to produce exploitable temperatures usable for the production of electricity. The radiation may concentrate on a point or on a line, where thermal energy is transferred to the heat transfer fluid. The intensity of concentration is defined by the concentration factor, the more this one is higher, the more reached temperature will be important. In this paper two optical technologies which showed promising results were compared, the first one is the Fresnel mirror and the second one is the parabolic trough. These two technologies are based on linear solar concentration. The main objective of this paper is to report the performance of these technologies by means of numerical analysis. A methodological analysis to design and evaluate the technical feasibility for the use of Fresnel mirror or parabolic trough in a Concentrating Solar Power (CSP) system has been carried out. The influence of ambient conditions and the percent of different types of energy loss, etc., are analyzed. An application on a site, in the south of Algeria (Hassi Rmel), is done. In this site, a project of hybrid natural gas/solar power plant with parabolic trough technology will be inaugurated before 2011.

Abstract Middle East – North Africa (MENA) region is characterized by increasing energy demand combined with high energy costs and short reserves of fossil fuels. Hence, the knowledge of the spatial and temporal variability of Global Horizontal Irradiance (GHI) is necessary for assessing the efficiency of alternative energy sources. In this study, satellite retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS, versions 6 and 6.1) and radiative transfer model simulations are used to evaluate the effect of aerosol optical properties on GHI under cloud-free conditions in the MENA region. The modeled GHI is validated against ground-based measurements at six MENA sites. Due to induced uncertainties in modeled GHIs, two site-adaptation methodologies (Empirical Quantile Mapping-EQM and Linear Least Squares-LIN) are further evaluated to diminish the systematic and dispersion errors. EQM is revealed to be more efficient, causing a significant correction to the statistical distribution of the modeled GHI. For almost all sites, modeled GHI values present the best statistical results when MODIS version 6.1 is used.

The durability of thick solar glass mirrors has been evaluated in this study by exposing samples at two potential exposure sites. Samples have been exposed for a period of 18 months at different orientations (North, South, East, and West) to evaluate the impact of orientation on the durability. The samples performance has been evaluated by measuring the specular reflectance of the glass samples before and after an appropriate cleaning process. In addition, the contact angle and the surface energy have been analysed. Obtained results show that mirror durability is very specific to the environmental conditions of the exposure site.

AbstractSolar energy from a parabolic trough solar field can be integrated to a combined cycle in several ways to decrease the already low emissions. This is accomplished in an integrated solar-combined cycle system (ISCCS). The trough parabolic collector technology has been chosen among several technologies for the great possibility of applying it in our strongly sunny country and considering its simplicity of operation which proved its profitability and its reliability. These solar power plants have an attractive future for their simple realization, their low costs and especially their weak emissions of gas with greenhouse effect (compared to those of SEGS II to IX). The collector performance model described in this paper was linked with the TRNSYS simulation program and hour by hour simulation of the energy gained by the collector was determined using the Algerian site radiation data. To sum up, the results are discussed in detail.The goal is to determine the most favorable conditions for a better power generation.

AbstractBecause of clean renewable electric power technologies is the human's future, a great number of parabolic trough power plants with different configurations are being considered for deployment in different locations in our world. It is necessary to study the operating performance of the concentrator solar power plant located in typical sites of Algeria, in this work for reference of the feasibility study of this technology in Algeria, it is essential that the plant designs will be optimized for each specific location. This paper is divided in three big sections; the first one is the implantation of parabolic trough solar power plants in different Algerian locations to see if this installation gives us usable electricity. The second section is to determine the best combination of available solar technological components (collectors, receivers, heat transfer fluids) and finally to make an economic study and gives a solution to minimize the levelized cost of electricity. The results shows that Algeria is one of the best world locations to produce usable electricity from solar thermal energy also the results could be useful to make decisions to realize such projects