Asmae Khaldoun

Analysis and mapping of the heating and cooling degree-days for Morocco at variable base temperatures

The purpose of this study is to evaluate, analyse and draw up maps of the heating and cooling degree-days (CDD) for Morocco. Data from 37 weather stations around Morocco during 10 years (2000–2009) were used. The mean heating and CDD at base temperatures of 18°C and 21°C, respectively, were presented. The effect of the geographical conditions such as latitude, longitude and elevation on the heating and CDD was investigated using the regression approach and the counter maps were performed using the digital elevation model of Morocco. To provide more accurate information to building designers and engineers, the heating and CDD were also calculated and tabulated for cities representing the six Moroccan climatic regions at different base temperatures varying from 12°C to 20°C for heating and from 20°C to 28°C for cooling, with a step of 1°C.

Lotus effect and super-hydrophobic coatings for concentrated solar power systems (CSP)

CSP reflectors are a key component for CSP technology and are characterized by their specular reflectance (SR), the degree to which a mirror is capable of transferring directed radiation to a target receiver surface. The accumulation of dust on the surface of the reflectors can decrease the ability of their mirrors in reflecting the radiation to the receiver causing an important decrease in the power plant efficiency and an increase of electricity production cost. The aim of this paper is to identify polymeric super hydrophobic coating materials in order to create lotus effect on the CSP reflectors with self-cleaning, anti-icing and anti-contamination properties on the CSP reflectors, especially that the CSP power plants are usually installed in desert area, which brings out the issue of water resources. In this study, the lotus effect will be presented alongside with different hydrophobic coating techniques. Later, a comprehensive analysis of the applications, advantages and disadvantages of hydrophobic coating for CSP mirrors will be presented. A comparative study will be conducted to choose the most suitable Nano-coating material for CSP in terms of cost to efficiency ratio as well as the future work and research in this specific field. It is crucial to develop super-hydrophobic coatings that will keep the panels clean and retain reflectivity with minimal maintenance and water requirements. Super-hydrophobicity is defined by the geometry of a water droplet on a surface. The lotus effect occurs when the apparent water contact angle (CA) is higher than 150° and when the water contact angle hysteresis (CAH) is lower than 10° to create a self-cleaning effect.

Building of a PV DSSC small scale prototype based TiO 2 nano coating with natural pigment

The principle of power generation by dye-sensitized solar cells has been known since the pioneering work of Gerischer and Tributsch in the sixties and seventies, wherein the introduction of Nano porous electrodes in 1990 by Grätzel improved the conversion efficiencies of the cell to about 7%. In this paper, we will construct a DSSCs small scale prototype. It will clearly picture how do DSSCs work. We will be using conducting glass, TiO2 paste, KI and I2 for the oxidation-reduction reaction, with the action of an anode and cathode. We will use natural red dye (from strawberries juice) that, while interacting with TiO2, will enhance the light absorption properties.

On the analysis of suitable ageing tests of first-surface CSP mirrors in Moroccan outdoor conditions

Desert areas are considered to be the most suitable sites for CSP power plant installations due to their high irradiance, principally the direct normal irradiance (DNI), as well as the flat land scape and lower population densities. However, CSP reflector components are exposed to very harsh weather conditions in desert areas, such as wind storms, strong irradiation flux, scarcity of water needed for the cleaning of the reflectors, as well as sand and dust storms. These degradation factors can seriously affect the specular reflectance, surface morphology and therefore the overall efficiency of the CSP plants. On the other hand, CSP power plants installations can also be sited in coastal areas or industrial areas, which exposes the solar reflectors to salty environment or to Sulfur Dioxide (SO2) due to high levels of pollution in industrial sites. Previous work of the authors has been dedicated to the preparation of several types of highly reflective CSP mirrors, prepared experimentally by the deposition of a metallic layer of Copper (50nm) covered with a reflective layer of Silver (100 nm) protected with layers of Aluminum Oxide (AhO3) and Titanium Dioxide (TiO2) with thicknesses of 1 um and 50 nm, respectively. The aim of this work consists on studying the appropriate ageing tests suitable for the nature of different mirror samples and the particularity of the different potential sites in Morocco where the CSP reflectors can be potentially exposed.

Deposition of transparent Aluminum Oxide (Al 2 O 3 ) films on silvered CSP mirrors

This work consists on the improvement of first surface silvered thick glass mirrors. Several types of CSP mirrors based on different Physical Vapor Deposition techniques (PVD) and the presence or absence of the copper protective back layer were prepared: ([Ag Sputtered], [Ag Evaporated], [Cu Sputtered-Ag Evaporated], [Cu Evaporated-Ag Sputtered], [Cu Evaporated-Ag Evaporated] and [Cu Sputtered-Ag Sputtered]). The UV-VIS-NIR measurements have shown that the different combinations of Silvered mirrors have approximately the same Specular Reflectance. The mirrors with the Copper back protective layer were chosen as the optimal mirror combinations since the [Ag-Evaporated] and the [Ag-Sputtered] mirrors presented stability and adhesion problems during the top protective layer deposition process. A transparent Aluminum Oxide (Al2O3) protective layer was deposited on top of the selected mirrors using Dip-coating and Ion Layer Gas Reaction (Spray-ILGAR) deposition techniques. After the deposition of the protective layer, the optical properties, thickness, composition and surface morphology of the mirrors were tested. The results showed that the Specular Reflectance decreased after the deposition of Al2O3 layer by Dip-coating technique. On the other hand, an improvement in the Specular Reflectance of the [Cu Sputtered-Ag Sputtered] mirror was noticed after the deposition of Al2O3 with the ILGAR technique. An increase in the diffuse reflectance after the deposition of the Al2O3 protective layer by ILGAR method was also observed, this can be explained by the presence of some roughness on the surface of the mirror, which was confirmed by the SEM pictures. From these results, it can be concluded that the Al2O3 protective layer deposition by ILGAR technique is a very promising technique since enhances the specular reflectance of the mirrors. The final prepared mirror combination is composed of thick glass substrate, covered with a metal back layer of Sputtered Copper (50 nm), a reflective layer of Sputtered Silver (100 nm) deposited on top of the Copper layer, and a top protective layer of Al2O3 deposited by Spray-ILGAR technique.

Development and integration of innovative low-cost PV windows based on dye sensitized solar cells technology: Application in Morocco

In This paper, we have discussed one example of the third generation solar cells, called nanocrystalline dye sensitized solar cells DSSC or Gratzel cell. An extensive literature study was conducted and the results show that the Nanocrystalline dye sensitized solar cells DSSC are considered as a novel and low cost photovoltaic technology. Compared with silicon solar cells, they are insensitive to impurities in fabrication process, which accelerates a transition from research laboratory to the mass production line. From the perspective of application, low weight and flexibility of DSSCs are desirable for the portable electronic device. It is found that DSSCs work better than silicon solar cells in the darker condition, for example, in the dawn and dusk, and also the overall efficiency is not seriously affected in the high temperature. In addition, the transparency and varied color of DSSCs are very important properties that make these cells suitable for a variety of important applications such as, windows, sunroofs, cellphones, etc.... The application of DSSC as smart window has very important impact on the electricity generation on buildings. However, its application on the glass window can affect the transmission of sun light to the house and decreases the heat gain provided by the sun [2]. In this work, a detailed simulation using Design builder software is conducted to compare the energetic consumption and internal gain received by buildings with transparent windows, and buildings with colored windows.

Thermal auditing of buildings: essential step towards designing energy efficient houses

This project provides a reference on how to perform a complete thermal analysis and brings a concrete example using different tools and equations for the estimation of the heating or cooling loads of residential buildings. For this purpose, different methodologies and calculations done by auditing organisms that evaluates how efficient the building is and its state of insulation was used. After determining all the criteria an insulated building needs to have, we applied it in a house model and we made the financial estimation of the loads needed to create comfort conditions in the building under analysis.

Direct normal irradiation-based approach for determining potential regions for concentrated solar power installations in Morocco

ABSTRACT In this study, potential sites for concentrated solar power (CSP) installations in Morocco are investigated based on direct normal irradiation (DNI). The DNI data of four Moroccan sites (Missour, Erfoud, Zagora and Tantan) were collected from different satellite databases (NASA SSE, PV GIS-Helioclim, Climate-SAF PVGIS and Solar Med Atlas). However, it is required to mitigate the risks resulting from uncertainties of satellite-based irradiation data by combining satellite data to ground measurements of at least 1 year. The ground-measured data reported in this work are collected from MHP and MDI meteorological stations installed by IRESEN in collaboration with DLR and ONEE in the framework of the enerMENA project. The Liu and Jordan and the Collares Pereira and Rabl models were also used to determine the monthly and yearly average hourly DNI values. The results of this study suggest that Missour, Erfoud and Zagora represent potential sites for CSP power plants installations, except for Tantan.

Preparation of an amorphous optically transparent and hydrophobic Al 2 O 3 top-protective layer for first-surface CSP reflectors

In Concentrated Solar Power (CSP) application, top coatings are of tremendous importance as a way to protect the reflective layers form degradation and conserve the efficiency and durability of the mirrors. The choice of Al<inf>2</inf>O<inf>3</inf> as a top-protective coating for CSP reflectors is based on its high stability, hardness and transparency. In this study, high quality and stable CSP first-surface silvered thick glass mirrors were prepared with a transparent and hydrophobic amorphous Al<inf>2</inf>O<inf>3</inf> top-protective layer with different thicknesses (1µm − 4µm) in order to investigate the effect of the film-thickness on the optical properties and surface morphology of the samples. The spectrophotometric measurements were conducted using a Perkin Elmer Lambda 950 UV/VIS/NIR Spectrophotometer and showed no significant change in the optical properties of the amorphous Al<inf>2</inf>O<inf>3</inf> layers with different thicknesses. The surface morphology was characterized using scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results show that increasing the thickness of the Al<inf>2</inf>O<inf>3</inf> layer up to 3 µm increased the surface hydrophobicity of the mirrors whereas a decrease in the water contact angle was noticed with 4 µm thickness. The measured water contact angles (WCA) were 94°, 98°, 102° and 95° for 1 µm, 2 µm, 3 µm and 4 µm, respectively. A decrease in the water contact angle (WCA=33°) was noticed by achieving a phase transformation from amorphous to crystalline (γ-Al2O3) using annealing at 800°C for 2 hours, exhibiting a hydrophilic behavior.

Experimental Approach of Measuring Thermal Properties for Ecological Materials Based on Additives Cork or Wool and Illite

This work is a contribution to understand the thermal properties of Illite with ecological additives granular presented by cork or fiber by wool in order to use those composites in building construction, the composites are air dried. Knowing that the clay composites were studied before, a series of experimental studies confirmed by complete theoretical models were conducted using different methods such as the asymmetrical hot plate in transient, steady-state regime, and flash methods in order to determine the thermal properties of the composite clay with ecological additives. Also, an analysis of sensibility of thermal properties was studied. For this purpose, a thermal characterization using hot plate and flash methods confirmed by complete theoretical models was studied. Then an analysis of the physicochemical characterization of clay was done to determine its characteristics. Finally, a study of depth heat flow diffusion was conducted to see the effect of additives on penetrating exterior heat flow inside house.