Educations and Awards

  • 2011-2012
    Post-Doctoral Associate, MIT, USA
    Post-Doctoral Associate, Center for Clean Water and Clean Energy, Mech. Eng. Dept, MIT. (one year).
  • 2005-2010
    PhD Mechanical Engineering ( Energy ), University of Waterloo
    PhD, Mechanical Engineering. University of Waterloo, thesis title “Thermodynamic Modeling and Thermo-economic Optimization of Integrated Trigeneration Plants Based on Organic Rankine Cycle”. Dec. 2010.
  • 2001-2003
    M.Sc. Mechanical Engineering (Energy), KFUPM
    Thesis title “Test Facility Development For Small Centrifugal Compressors”.
  • 1995-2001
    B.Sc Mechanical Engineering, KFUPM
    - Concentration in Thermofluid.
    - Senior project was mainly an experimental work related to the control of stall in a centrifugal compressor.
  • Awards
    Best Researcher Award, 2016, KFUPM
    Best Researcher Award, 2016, KFUPM
  • Awards
    Best project Award, KFUPM
    Best project Award, KFUPM


  • Oct 2016 – Present
    image Director of the Center of Excellence in Energy Efficiency

    King Fahd University of Petroleum & Minerals - KFUPM

    Leading the Center for conducting energy auditing and energy efficiency improvement for industrial projects and applied research, specifically for small & medium-scale industries and commercial buildings; as well as conducting related courses & students training.
  • Aug 2014 – Present
    image Director of the Center of Research Excellence in Renewable Energy

    King Fahd University of Petroleum & Minerals - KFUPM

    Leading the Center for conducting industrial projects, applied research, training/courses, and developing cutting edge technologies related to renewable energy.
  • Jul 2001 – Present
    image Faculty Member

    King Fahd University of Petroleum & Minerals - KFUPM

    Leading the Center for conducting industrial projects, applied research, training/courses, and developing cutting edge technologies related to renewable energy.
  • Jul 2017 – Aug 2017
    image Visiting professor in the Oxford Institute for Energy Studies (an RIC of the University of Oxford)

    University of Oxford

    Worked in energy policy for grid-connected rooftop solar photovoltaics systems.
  • Jun 2015 – Aug 2015
    image Visiting professor in the Solar Energy Research Institute

    National University of Singapore

    Worked in solar air conditioning systems using energy recovery techniques to enhance their performance.
  • Jun 2002 – Jul 2002
    image Visiting consultant, Rotating Equipment Division, Consulting Services Department (CSD)

    Saudi Aramco

    Worked in issues related to compressors and their international standards for performance testing.

Research Projects Summary

  1. Energy auditing, energy efficiency improvement, and energy management for small & medium-scale industries, continuous several ongoing applied projects each year.

  2. Energy auditing, energy efficiency improvement, and energy management for commercial building, continuous several ongoing applied projects each year.

  3. Thermodynamic Optimization of a Novel Solar-Trigeneration Plant Using Hybrid Steam and Organic Rankine Cycles, JF101013, DSR, KFUPM, PI.

  4. Seawater Desalination using Thermal, Solar, and Hybrid Systems, including Humidification Desalination, MIT-KFUPM, Co-I.

  5. Thermodynamics Optimization of Solar Thermal Power Tower Systems with Thermal Storage, SB121010, DSR, KFUPM, PI.

  6. Investigation of Photovoltaic Panels Subjected to Uniform Cooling, KACST, Co-I.

  7. Investigation of Solar Energy Driven Combined Power and Cooling Thermodynamic Cycle,DSR-SABIC, Co-I.

  8. Application of Photovoltaic-Thermal Hybrid Solar Collector System in Saudi Arabia, NSTIP, Co-I, completed.

  9. Community Awareness about Energy Conservation and the Importance of Renewable Energy Program, the Ministry of Higher Education, 2014 Co-I.
                برنامج توعية المجتمع حول ترشيد استهلاك الطاقة وأهمية الطاقة المتجددة ،الإدارةالعامة للبرامج التطويرية، وزارة التعليم العالي، باحت مشارك ، 2014


  10. Development and Assessment of a New Water Humidifier for Water Desalination Applications, IN131041, 2014, DSR, KFUPM, PI.

  11. Air Dehumidification for Air Conditioning and Water Desalination, KACST summer grant.

  12. Applications of Solar Chimney in Saudi Arabia, DSR-KFUPM, PI.

  13. Innovative Sustainable Water Desalination system using based on a heat pump with conventional or solar energy, DSR-KFUPM, Co-I.
    In progress

  14. Experimental and Modeling Development of an Optical Filter Based two-Channels Hybrid PV/T Solar Collector using Nanofluids, DSR-KFUPM, PI.
    In progress


  • Renewable energy (solar thermal, solar photovoltaics (PV), and wind energy)
  • Cogeneration
  • Trigeneration
  • Distributed/decentralized generation
  • Water desalination
  • Advanced thermal power cycles
  • Electrical grid-connection of renewable energy systems
  • Air-conditioning systems
  • Techno-economic studies for energy systems
  • Life cycle analysis
  • Energy efficiency & energy auditing
  • Energy policy & regulations

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Dr. Al-Sulaiman Fahad has more than 100 published scientific papers and several patents. He led several research projects in energy.

To see updated published papers Click here

  1. Effect of environmental dust particles on laser textured yttria-stabilized zirconia surface in humid air ambient
  2. JOURNAL PAPERS BS Yilbas, H Ali, A Al-Sharafi, F Al-Sulaiman, C Karatas - Optics & Laser Technology, 2018


    Zirconium nitride is used as a selective surface for concentrated solar heating applications and one of the methods to form a zirconium nitride is texturing of zirconia surface by a high intensity laser beam under high pressure nitrogen gas environment. Laser texturing also provides hydrophobic surface characteristics via forming micro/nano pillars at the surface; however, environmental dust settlement on textured surface influences the surface characteristics significantly. In the present study, laser texturing of zirconia surface and effects of the dust particles on the textured surface in a humid air ambient are investigated. Analytical tools are used to assess the morphological changes on the laser textured surface prior and after the dust settlement in the humid air ambient. It is found that laser textured surface has hydrophobic characteristics. The mud formed during condensate of water on the dust particles alters the characteristics of the laser textured surface. The tangential force required to remove the dry mud from the textured surface remains high; in which case, the dried liquid solution at the mud-textured surface interface is responsible for the strong adhesion of the dry mud on the textured surface. The textured surface becomes hydrophilic after the dry mud was removed from the surface by a desalinated water jet.

  3. Preparation, characterization and thermal regulation performance of cement based-composite phase change material
  4. JOURNAL PAPERS A Sarı, A Bicer, A Karaipekli, FA Al-Sulaiman - Solar Energy Materials and Solar Cells, 2018


    Thermal behavior of a building mass can be enhanced using phase change materials (PCMs) as latent heat thermal energy storage (LHTES) materials. Such type thermal enhanced construction materials can be used for passive solar heating, ventilating and air conditioning (HVAC) purposes in building envelopes. This work was focused on development, characterization of LHTES properties and establishment of thermal performance of a cement-based composite PCM (Cb-CPCM) plaster for low-temperature LHTES targets in buildings. The eutectic mixture of capric acid(CA)-myristic acid(MA) was absorbed as 28 wt% by cement through vacuum embedding method. The chemical structures and morphology cement/(CA-MA) composite and its pure components were investigated by FT-IR, XRD and SEM techniques. The LHTES characteristics of the produced Cb-CPCM were determined by DSC analysis. The DSC results indicated that the form-stable Cb-CPCM melted and solidified at 21.13 and 17.90 °C and had corresponding LHTES capacities as 41.78 and 39.56 J/g, respectively. The TGA results and cycling test revealed that the Cb-CPCM had high thermal resistance, long-term cycling chemical stability and reliability. Furthermore, two cubic test rooms were built with/without Cb-CPCM to compare thermo-regulating performance in laboratory-scale. The temperature difference between the indoor temperatures of the cubes was measured as averagely 0.78 °C during heating period. All results exhibited that the prepared Cb-CPCM could be considered as a potential composite PCM for low-temperature HVAC intentions in buildings.

  5. Feasibility study of the grid connected 10MW installed capacity PV power plants in Saudi Arabia.
  6. JOURNAL PAPERS S Rehman, MA Ahmed, MH Mohamed, FA Al-Sulaiman - Renewable and Sustainable Energy Reviews, 2017


    The study presents technical, environmental and economic aspects for the selection of viable sites for constructing 10 MW installed capacity grid connected photovoltaic power plants in Saudi Arabia. Available photovoltaic modules are analyzed and one is chosen for the analysis. Meteorological data like global solar radiation, sunshine duration, dry bulb temperature, and relative humidity was used to conduct the feasibility analysis using RETScreen software in terms of energy production, greenhouse gas (GHG) emissions, and financial parameters for the 44 sites. Bisha is found to be the best site for the installation of 10 MW installed capacity grid connected photovoltaic power plant due to highest solar radiation intensity and longer sunshine duration. Both of these factors contribute to higher energy yield and less GHG emissions. On the lower extreme, Sulayel is found to be generating minimum energy from the same installed capacity of PV panels. Finally, it is recommended to commence constructing large grid-connected photovoltaic plant at Bisha with 70% government grant because the electricity export rate in Saudi Arabia is 72.57% cheaper than global price.

  7. Silica fume/capric acid-palmitic acid composite phase change material doped with CNTs for thermal energy storage.
  8. JOURNAL PAPERSA Sarı, A Bicer, A Al-Ahmed, FA Al-Sulaiman, MH Zahir… - Solar Energy Materials and Solar Cells, 2017


    Though very promising, fatty acids suffer from low thermal conductivity and leakage, which limits their heat storage applications. To overcome these problems, we used silica fume (SF) to house the fatty acid and prevent leaching during phase change and incorporated different amount (1.0, 3.0 and 5.0 wt%) of CNTs to improve the thermal conductivity to the desired level. For the experimental temperature range and better performance an eutectic mixture of capric acid(CA)-palmitic acid(PA) was prepared and investigated. The physicochemical and morphological characterizations of the fabricated shape stabilized-composite PCMs (SS-CPCMs) with/without CNTs were carried out using FTIR, XRD and SEM instruments. The DSC analysis results showed the SS-CPCMs had phase change temperatures of 19–26 °C and high latent heat capacity of 46–49 J/g, which are suitable for thermal energy storage (TES) in buildings. The SS-CPCMs showed good cycling TES reliability and chemical stability and also exhibited excellent thermal durability up to 140 °C. The CNTs doping process caused an appreciable increase in thermal conductivity and significantly reduced the charging and discharging times of the SS-CPCMs. Consequently, due to higher thermal conductivity, the SS-CPCM doped with 5.0 wt% CNTs can be considered as more promising composite for passive solar thermoregulation of building envelopes.


    Thermodynamic analysis was conducted, in detail, to compare the performance of an air conditioning system with and without an air-membrane heat and mass exchanger. The study evaluated the performance of the system considering four promising new refrigerants: R1234yf, R1234ze, R32, and R423A. To evaluate the performance of the system, key performance parameters were used, including, coefficient of performance (COP), exergy destruction rate, second law efficiency, compressor work, irreversibility ratio, fuel depletion ratio, and productivity lack. In addition, the effect of varying the compressor pressure ratio, effectiveness of the membrane, and the relative humidity of fresh air on the performance of the system were evaluated for both configurations. The performance of an air conditioning system significantly improves when an air-membrane heat and mass exchanger is used. The main reason of this improvement is the significant drop in the cooling load and, consequently, the compressor input power. Furthermore, the study showed that COP as a measure of performance is not enough to have an appropriate comparison for the performance and further detailed analysis is needed, such as exergy analysis. Therefore, exergy analysis was also conducted to fully assess the advantages of using a membrane with an air conditioning system. From thermodynamics point of view, the study showed that R1234ze has the best performance while R32 has the lowest performance.

  9. Characteristics of a solar selective absorber surface subjected to environmental dust in humid air ambient
  10. JOURNAL PAPERSBS Yilbas, H Ali, A Al-Sharafi, N Al-Aqeeli, N Abu-Dheir, FA Al-Sulaiman - Solar Energy Materials and Solar Cells, 2017


    Solar refractory selective absorber surfaces, such as TiN coatings, suffer from dust settlements, which become critically important in terms of the efficient operation of a solar receiver. In the present study, environmental dust characteristics and dust settlement on TiN coating surface are investigated. Water condensation on the dust particles in humid air ambient is simulated while mimicking the actual environmental water condensation. The size distribution of the dust particles is analyzed and the geometric features of the particles are assessed via introducing the shape factor and the aspect ratio. The tangential force required removing the dust particles and dry mud, which is formed from the dust particles and water condensate, from TiN coating surface is measured incorporating the micro-tribometer. It is found that the dust particles have various shapes and the sizes with the average size of the dust particles in the order of 1.2 µm. Dust particles compose of various elements including alkaline and alkaline earth metals. The dissolution of alkaline and alkaline earth metal compounds in water condensate results in a liquid solution, which flows towards the coating surface under the gravitational force. The liquid solution does not form a continuous film at the interface of the dust particles and the coating surface because of the spreading coefficient. The liquid solution increases the tangential force required to remove the dry mud from the coating surface once it dries out.

  11. A comparative study of a small-scale solar PV power plant in Saudi Arabia
  12. JOURNAL PAPERSSS Rashwan, AM Shaaban, FA Al-Sulaiman - Renewable and Sustainable Energy Reviews, 2017


    The aim of this study is to perform an economic and environmental feasibility study of switching the electrical power supply of a small building located in Dhahran, Saudi Arabia, from the electrical grid into renewable energy provided by solar photovoltaic (PV) modules. The PV power plant is evaluated based on the international Photovoltaic Project Model with the same power capability of 12 kW. The feasibility study was based on the new electricity tariffs for the governmental and commercial sectors of 4.0 and 8.0 cents/kWh, respectively. Three scenarios were considered for several cities of Saudi Arabia, taking into account the most recent prices for a PV system.

  13. Effect of temperature on the photovoltaic performance and stability of solid-state dye-sensitized solar cells: A review
  14. JOURNAL PAPERSU Mehmood, A Al-Ahmed, FA Al-Sulaiman, MI Malik… - Renewable and Sustainable Energy Reviews, 2017


    Temperature is probably the most important outdoor variable that affects the photovoltaic performance of the dye sensitized solar cells (DSSCs). Overall stability of DSSCs depends on the properties of charge mediator (electrolyte) between photoanode and counter electrode. The liquid electrolytes show high power efficiency owing to their high dielectric constants to dissolve many ionic salts and additives. However, they may limit the outdoor applications in high temperature region, due to their low boiling points (highly volatile). The objective of this study is to highlight the prospects of solid state dye-sensitized solar cells and its benefit in higher temperature environment. The current review is comprised of four sections. In the first section (introduction), the effect of temperature on the conventional and solid-sate DSSCs is briefly described. In the second section, the mechanism of solid-state DSSCs is explained. Third section we covered recent advances in ss-DSSCs in detail. Finally, the scope of DSSCs in high temperature environment critically analyzed in section four.

  15. Internal flow and heat transfer in a droplet located on a superhydrophobic surface
  16. JOURNAL PAPERSA Al-Sharafi, H Ali, BS Yilbas, AZ Sahin, N Al-Aqeeli, FA Al-Sulaiman - International Journal of Thermal Sciences, 2017


    Flow and heat transfer inside a droplet located on a superhydrophobic surface are examined for various droplet contact angles. A polycarbonate wafer is immersed into a liquid acetone for 6 min to crystallize wafer surface generating a surface texture consisting of micro/nano pillars. To reduce the surface energy of textured polycarbonate wafer, octadecylichlorosilane coating is applied, which results in the superhydrophobic characteristics of the surface. A water droplet is formed on the superhydrophobic surface and it is heated from a constant heat source at the droplet bottom. The metallic powders consisting of Inconel 718 alloy with a nominal diameter of 30 μm are sprayed at the superhydrophobic polycarbonate surface to establish foundations for a constant temperature heating of the droplet. It is found that the averaged Nusselt and the Bond numbers increase with increasing droplet contact angle. A new number, Ayse, is introduced to correlate the Bond number and the droplet contact angle, which is then used to develop the relation between the Nusselt number and the Ayse number. The Nusselt number increases with increasing Ayse number in the form of a power relation.

  17. Recent progress and remaining challenges in organometallic halides based perovskite solar cells
  18. JOURNAL PAPERSU Mehmood, A Al-Ahmed, M Afzaal, FA Al-Sulaiman… - Renewable and Sustainable Energy Reviews, 2017


    The efficiency of perovskite solar cells (PSCs), based on thin film organometallic halides/mixed-halides, has rapidly increased from 3.8% in 2009 to 20.1% by 2015. Enhanced efficiency as well as the flexibility in material development and the structure are the primary reasons for their emergence in the photovoltaic market. Inherently distinctive properties of perovskite materials are mainly responsible for the enhanced efficiency. A variety of different techniques and device architecture have been employed for the fabrication of high-performance perovskite solar cells. As many parameters can be optimized, the efficiency of these devices can be further improved. This review highlights the intrinsic properties of lead halide perovskites and the recent progress in the application of these novel materials in producing efficient solar cells. Key factors affecting their solar performance are also highlighted. Scope and the need for lead free halide perovskites are also discussed.

  19. Performance characteristics of a solar driven lithium bromide-water absorption chiller integrated with absorption energy storage
  20. JOURNAL PAPERSNI Ibrahim, FA Al-Sulaiman, FN Ani - Energy Conversion and Management, 2017


    The use of solar–assisted absorption chiller for space cooling is limited to availability of solar radiation; hence, energy storage is very crucial in order to achieve extended hours of cooling operation. In this study, operational and performance characteristics of a solar driven lithium bromide-water absorption chiller integrated with absorption energy storage of the same working fluid are investigated. The integrated system simultaneously provides cooling and charging of the absorption energy storage during the hours of solar radiation. Simulation of the integrated system is carried out based on first law of thermodynamics. Effects of weather variables such as solar radiation and the influence of coupling absorption energy storage with an absorption chiller are investigated. The results indicate that cooling effect of the chiller varies with the variation of solar radiation, with maximum value of 20 kW for a collector area (Ac) of 96 m2 on a typical day in July, Dhahran, Saudi Arabia. The cooling COP of the integrated system during cooling/charging and discharging is found to be 0.69 and the energy storage density of the absorption energy storage is 119.6 kWh/m3. Furthermore, the operational characteristics of the proposed system showed that the internal operating parameters of the integrated chiller-absorption energy system such as solution temperatures and pressures are within reasonable levels. Hence, this indicates the possibility of integrating the absorption energy storage with absorption chiller.


    A comparison of energy and exergy analyses for an air conditioning system with and without an air membrane heat and mass exchanger was performed. The study considered several key performance parameters, including coefficient of performance, second law efficiency, exergy destruction rate, evaporative cooling rate, compressor input power, fuel depletion ratio, relative irreversibility, productivity lack, exergetic factor, and exergetic improvement potential. A membrane significantly improves the second law efficiency, while it has only a small effect on the coefficient of performance. However, in the presence of a membrane both the required cooling energy and the required input power decrease significantly. In addition, the total exergy destruction rate is lower when a membrane is used, and the evaporator has the highest irreversibility ratio compared with the other components. The total exergy destruction decreases, on average, by more than 50% when a membrane is used compared with the case when no membrane is used. Therefore, the second law efficiency increases when a membrane is used and this study reveals that it increases by more than 5%.

  21. A review for phase change materials (PCMs) in solar absorption refrigeration systems
  22. JOURNAL PAPERSMMA Khan, R Saidur, FA Al-Sulaiman - Renewable and Sustainable Energy Reviews, 2017


    Energy storage has become an important part in renewable energy technology systems. Solar thermal systems, unlike photovoltaic systems with striving efficiencies, are industrially matured, and utilize major part of sun's thermal energy during the day. Yet, it does not have enough (thermal) backup to keep operating during the low or no solar radiation hours. New materials are selected, characterized, and enhanced in their thermo-physical properties to serve the purpose of a 24 h operation in an efficient thermal energy storage system (TESS). Solar absorption refrigeration system requires a continuous operation in many of its applications (food storage, space cooling etc), which in turn requires an efficient TES system utilizing material with high heat of fusion, eg. phase change materials (PCMs). This review is a comprehensive evaluation of suitable PCM selection, methodologies of integration, enhancements and challenges for operating temperatures of each component in a single-effect solar absorption system affecting its performance. Observations and lessons from previous studies are discussed in detail. Recommendations based on investigation results, advantages and drawback of PCMs, PCM enhancement options, energy, exergy and cost analysis are made for the future research direction.

  23. Experimental testing of the performance of a solar absorption cooling system assisted with ice-storage for an office space
  24. JOURNAL PAPERSNI Ibrahim, MMA Khan, IM Mahbubul, R Saidur, FA Al-Sulaiman - Energy Conversion and Management, 2017


    Energy storage plays a vital role in shifting cooling energy load from period of peak demand to that of low demand. This paper reports performance data of an ice-storage unit in solar absorption cooling system for cooling an office space. The cooling system consists of ammonia-water absorption chiller, evacuated tube solar collectors and ice-storage. Experiments were carried out on two consecutive days in each of the month of March and October in Dhahran, Saudi Arabia. The ice-storage unit was charged on the first day and the cool energy discharged on the other day. The results showed average coefficient of performance (COP) of the chiller during charging as 0.43 and 0.47 for the months of March and October, respectively. The results also indicate that the ice-storage can provide a backup time of about 5–6 h, which is sufficient to cool the given space during the early hours of chiller warm-up.

  25. Analysis of environmental dust and mud adhesion on aluminum surface in relation to solar energy harvesting
  26. JOURNAL PAPERSG Hassan, BS Yilbas, MA Samad, H Ali, FA Al-Sulaiman - Solar Energy, 2017


    In the present study, adhesion of dried mud solution formed on the aluminium surface is investigated and the characteristics of the mud solution are examined using the analytical tools. The adhesion force and the adhesion work required to remove the dried mud solution from the aluminium surface are measured. The findings revealed that the dried mud solution forms crystals with varying sizes on the aluminium surface depending on the mud drying temperature. The dissolution of alkaline and earth alkaline compounds in water is responsible for the formation of crystals on the aluminium surface. The adhesion force and the adhesion work increase significantly as the mud solution drying temperature increases.

  27. Heat transfer enhancement of phase change materials for thermal energy storage applications: A critical review
  28. JOURNAL PAPERSNI Ibrahim, FA Al-Sulaiman, S Rahman, BS Yilbas… - Renewable and Sustainable Energy Reviews, 2017


    This paper presents a state-of-the-art review on various techniques of heat transfer enhancement in latent heat thermal energy storage (LHTES) systems. Heat transfer enhancement in LHTES systems can be achieved through either geometric configuration and/or thermal conductivity enhancement. The use of extended surfaces such as fins or heat pipes is a common technique for heat transfer enhancement in LHTES systems and therefore, reviewed in details in this paper. Next, we studied the thermal conductivity enhancement techniques, which include the use of porous materials, nanoparticles with high thermal conductivity, and low-density materials. Finally, studies involving combined techniques for heat transfer enhancement are reviewed in the paper. The paper discusses research gaps in the methods of heat transfer enhancement for LHTES systems and proposed some recommendations.

  29. Solar absorption systems with integrated absorption energy storage–A review
  30. JOURNAL PAPERSNI Ibrahim, FA Al-Sulaiman, FN Ani - Renewable and Sustainable Energy Reviews, 2017


    Solar driven absorption systems are becoming more tractive and common in air conditioning industry. However, the issue of intermittency of the solar energy remains the critical concern in real applications. Hence, energy storage is inevitable to bridge the energy demand and intermittency gap. Among the existing thermal energy storage options, sensible heat storage is the most widely adopted in solar thermal applications. Research interest on absorption energy storage is increasing recently owing to low heat loss and high-energy storage capability. This paper presents a specific review on solar absorption energy storage and its integration with conventional absorption chillers. Specific future research directions on the subject are highlighted in the paper. These include economic viability of the absorption energy storage, improved design of heat exchangers and considering the concept of absorption energy storage as an option for shifting solar thermal energy collected during the peak day-hours to the off peak night-hours for air conditioning, among others.

  31. Optical properties of various nanofluids used in solar collector: A review
  32. JOURNAL PAPERSSHA Ahmad, R Saidur, IM Mahbubul, FA Al-Sulaiman - Renewable and Sustainable Energy Reviews, 2017


    Different properties of nanofluids have been studied by the researchers since the last two decades. Most of the studies have focused on the thermal properties of the nanofluids. However, optical properties have considerable contribution to heat absorbance in nanofluids. Therefore, it is necessary to study the different parts of solar spectrum (optical properties) to utilize nanofluids in solar thermal applications. The optical properties (absorption, transmittance, scattering, and extinction coefficient) based on metal, metal oxide, carbon nanotubes, graphite, and graphene have been reviewed thoroughly in variation with particle size and shape, path length, and volume fraction. The present investigational outcomes about the nanofluids showed that optical solar absorption increased accordingly with increasing nanoparticle size and volume concentration. However, there were some conflicting results on the effects of nanoparticle size on absorption, in which the particle size has an insignificant effect on overall optical properties. Moreover, it was observed that path length has some remarkable effects over optical absorption of nanofluids. The experimental results revealed that the transmittance of nanofluids has indirect relation with nanoparticle size, volume fraction, and path length. The scattering of light is directly proportional to the volume concentration and particle size of metallic particles. Overall, results of various elements showed that the presence of large particles and particle agglomerates leads to significant amount of light scattering. As a result, overall extinction coefficient will be increased. Therefore, an optimization of these properties need to be maintained for stable and cost-effective nanofluid.

  33. A novel design of a multistage stepped bubble column humidifier for the humidification of air
  34. JOURNAL PAPERSHM Abd-ur-Rehman, FA Al-Sulaiman - Applied Thermal Engineering, 2017


    The operating parameters for the optimum performance of a novel multistage stepped bubble column humidifier design were experimentally determined. An improved humidification-dehumidification (HDH) desalination system can be obtained by integrating such a humidifier with a dehumidifier. The relationship between the variation of the pressure drop with varying water column height at different superficial velocities of air was evaluated. A water column height of 1 cm and superficial velocity of air of 25 cm/s provide the best humidifier performance at the lowest pressure drop. The performance of single-stage, two-stage, and three-stage bubble column humidifiers was evaluated in terms of the absolute humidity when the inlet water temperature is varied in the range of 35–75 °C. The absolute humidity increases exponentially with increasing inlet water temperature. The percentage increase in the absolute humidity achieved by the two-stage and three-stage bubble column humidifiers are, respectively 7–9% and 18–21% higher than that achieved by the single-stage bubble column humidifier.


    A detailed exergoeconomic analysis of an ejector-augmented shrouded horizontal axial wind turbine at three ejector inlet area ratios was conducted. Key exergoeconomic parameters examined include, cost rate of the power produced, exergy loss to cost rate, exergetic improvement potential, power produced, and air mass flow rate through the wind turbine. The findings demonstrate that the performance of the wind turbine improves as the ejector inlet area ratio increased, and the cost per kWh of the power produced decreases significantly with wind speed increased from about 2 $/kWh at 5 m/s to about 0.1 $/kWh at 15 m/s. On the other hand, the exergy destruction rate is relatively low while the exergy loss is relatively high.

  35. Effect of mud drying temperature on surface characteristics of a polycarbonate PV protective cover
  36. JOURNAL PAPERSBS Yilbas, H Ali, FA Al-Sulaiman, H Al-Qahtani - Solar Energy, 2017


    Chemo-mechanical characteristics of mud formed on polycarbonate PV cover are studied in relation to solar photovoltaic applications. Mud is formed from environmental dust and water condensate mimicking humid air conditions. Effect of mud drying temperature on chemo-mechanical and optical characteristics of mud-polycarbonate interface is investigated. Mud drying temperatures are set in the control chamber according to daily temperature distribution in Dammam area. Dry mud is later removed from surfaces, by pressurized distilled water, and mud residues left over on polycarbonate surface are examined. Analytical tools including scanning electron and atomic force microscopes, energy dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma mass spectrometry are incorporated for the characterization of mud solution, dry mud, and polycarbonate surface after dry mud removal. Adhesion work required to remove dry mud from polycarbonate surface is also determined from scratch tests data. It is found that alkaline (Na, K) and alkaline earth metals (Ca) compounds in dust particles dissolve in condensed water while forming chemically active mud solution, which settles at the interface between mud and polycarbonate surface under the gravity. This has a detrimental effect on cleaning of dusted polycarbonate surface because of mud solution, upon drying, increases adhesion between dry mud and surface as well as modifies microhardness and surface texture of polycarbonate surface. Mud residues left over on surfaces alters the friction coefficient of polycarbonate surface, which is more pronounced for the case in which drying temperature is high.


    In this study, energy and exergy analyses of supercritical carbon dioxide (sCO2) recompression Brayton cycles driven by solar thermal tower systems were conducted. A mathematical model is used to generate a surround heliostat field layout, which is optimized for the optical performance on an annual basis using differential evolution, an evolutionary algorithm. The model is also used to generate a recompression Brayton cycle, which uses the heat collected at the central receiver through the heliostat field. An auxiliary heat exchanger based on a combustion chamber was also added prior to the expansion turbine to keep the turbine inlet temperature constant, thus keeping the net power output uniform at 40 MW. Lastly, exergy analysis was conducted for the integrated system of the heliostat field and the recompression Brayton cycle. Also, a detailed chemical exergy analysis of the combustion chamber was performed. The developed mathematical model was implemented for six different locations (cities) in Saudi Arabia for a comparative analysis. The selected cities were Tabouk (North), Madinah (West), Dhahran (East), Riyadh (Central), Bishah (South), and Najran (South). The findings reveal that the highest annual average heat collected is for Madinah (938,400 kWh/day), followed by Tabouk (933,100 kWh/day). Consequently, the lowest annual average fuel hybridization of 5.82% is for Madinah followed by Tabouk (6.34%) for daytime hours. On the other hand, the highest annual average total exergy destruction rate is for Dhahran (199,250 kW), followed by Riyadh (192,699 kW) and the lowest is for Madinah (173,690 kW) followed by Tabouk (175,692 kW). Furthermore, the highest average exergy destruction takes place in the heliostat field and the second highest in the combustion chamber. In addition, the exergy destruction rate of the combustion process increases during the winter months when the solar radiation decreases.

  37. Transparent conductive oxide films for high-performance dye-sensitized solar cells
  38. JOURNAL PAPERSU Mehmood, M Afzaal, A Al-Ahmed, HM Yates, FA Al-Sulaiman - IEEE Journal of Photovoltaics, 2017


    In this paper, atmospheric pressure chemical vapor deposition of fluorine-doped tin oxide (FTO) thin films of various thicknesses and dopant levels is reported. The deposited coatings are used to fabricate dye-sensitized solar cells, which exhibited reproducible power conversion efficiencies in excess of 10%. No surface texturing of FTOs or any additional treatment of dye-covered films is applied. In comparison, the use of commercial FTOs showed a lower cell efficiency of 7.11%. Detailed analysis showed that the cell efficiencies do not simply depend on the resistivity of FTOs but instead rely on a combination of carrier concentration, thickness, and surface roughness properties.

  39. Comparative studies of encapsulation and glass surface modification impacts on PV performance in a desert climate
  40. JOURNAL PAPERSHM Walwil, A Mukhaimer, FA Al-Sulaiman, SAM Said - Solar Energy, 2017


    PV module encapsulation and glass covering processes play big role in reliability and performance of PV modules, especially under desert climatic conditions. In the present study, tests were carried out to compare the performance of five types of commercial glass cover and three types of commercial PV module encapsulates. The relative advantages of anti-reflective coated and textured glass cover, as well as, silicone and Ionomere encapsulant under clean and dusty conditions were examined in terms of PV module’s power output and temperature. The results revealed that silicone and Ionomere encapsulant do boost the power output of a clean PV module by 2–3% on average. However, ethylene-vinyl acetate (EVA) encapsulant dust-covered modules showed relatively better performance as compared to dust-covered Ionomere and silicone encapsulant modules. Clean modules encapsulated with silicone or Ionomere material exhibited higher module temperature relative to that of EVA encapsulant modules. Adding an anti-reflective coating and texturing module’s surface in some cases boosted the power output of a clean PV module by 6% on average. In addition, the study confirmed the fact that dust fouling can lead to a significant reduction in PV module power output (40% reduction after 10 months of exposure without cleaning). Anti-reflective coating of PV modules glass cover can relatively mitigate power reduction due to dust coverage.


    Performance analysis is conducted for a solar driven supercritical CO2 Brayton cycle combined with a multiple effect evaporation with thermal vapor compression (MEE-TVC) for power and desalinated water production. The study proposes two new different supercritical Brayton cycles, namely, the regeneration and recompression sCO2 cycles. A new efficiency equation for the combined power and water production is derived. The findings show that a 6.25% of efficiency increase results from utilizing the recompression cycle compared to the regeneration cycle. The effect of the fraction (f) of the heat entering the sCO2 cycle, turbine inlet temperature (TIT), and turbine inlet pressure (TIP) on the power to water ratio (PWR) and effective efficiency are also investigated. It is found that the PWR increases exponentially with respect to the increase in fraction reaching 2.8 and 3 kW/m3day for the regeneration and recompression cycle, respectively at a fraction of 0.8. To assess the variation of solar radiation at different locations, the study is performed for different regions of Saudi Arabia; and it is found that the highest productivity is that for the region of Yanbu, followed by Khabt Al-Ghusn, and the rest in a descending order are Jabal Al-Rughamah, Jizan, Al-Khafji, and Dhahran.

  41. Performance and cost assessment of solar driven humidification dehumidification desalination system
  42. JOURNAL PAPERSMI Zubair, FA Al-Sulaiman, MA Antar, SA Al-Dini… - Energy Conversion and Management, 2017


    A humidification-dehumidification (HDH) desalination system integrated with solar evacuated tubes was optimized. Then, the optimized system was assessed for the operation in different geographical locations, and the rate of freshwater production and cost per liter were determined in each location. The system design proposed in this paper uses a heat pipe design evacuated tube collector, which performs significantly better based on cost. An HDH desalination system with a closed-air/open-water loop, connected to the collector, was evaluated to determine the optimum operating parameters and the system performance during daytime (from 8 am to 3 pm), as well as the average day of each month for an entire year. The impact of the effectiveness of the humidifier and the dehumidifier, as well as, the number of collectors, were also studied. The analyses were performed for Dhahran, Jeddah, Riyadh, Sharurah, Qassim, and Tabuk to determine the effects of varying the geographical location. Sharurah has the highest calculated productivity of freshwater and Dhahran has the lowest at 19,445 and 16,430 L, respectively. To have a comprehensive study of the system proposed, a cost analysis was also performed to determine the feasibility of the system and the cost of water production. Results show that the price varied from $0.032 to $0.038 per liter for the locations evaluated.

  43. Global solar radiation and energy yield estimation from photovoltaic power plants for small loads
  44. JOURNAL PAPERSAZ Sahin, S Rehman, FA Al-Sulaiman - International Journal of Green Energy, 2017


    Daily global solar radiation on a horizontal surface and duration of sunshine hours have been determined experimentally for five meteorological stations in Saudi Arabia, namely, Abha, Al-Ahsa, Al-Jouf, Al-Qaisumah, and Wadi Al-Dawaser sites. Five-years of data covering 1998–2002 period have been used. Suitable Angstrom models have been developed for the global solar radiation estimation as a function of the sunshine duration for each respective sites. Daily averages of monthly solar PV power outputs have been determined using the Angstrom models developed. The effect of the PV cell temperature on the PV efficiency has been considered in calculating the PV power output. The annual average PV output energy has been discussed in all five sites for small loads. The minimum and maximum monthly average values of the daily global solar radiation are found to be 12.09 MJ/m2/d and 30.42 MJ/m2/d for Al-Qaisumah and Al-Jouf in the months of December June, respectively. Minimum monthly average sunshine hours of 5.89 hr were observed in Al-Qaisumah in December while a maximum of 12.92 hr in Al-Jouf in the month of June. Shortest range of sunshine hours of 7.33–10.12 hr was recorded at Abha station. Minimum monthly average Solar PV power of 1.59 MJ/m2/day was obtained at Al-Qaisumah in the month of December and a maximum of 3.39 MJ/m2/day at Al-Jouf in June. The annual PV energy output was found to be 276.04 kWh/m2, 257.36 kWh/m2, 256.75 kWh/m2, 245.44 kWh/m2, and 270.95 kWh/m2 at Abha, Al-Ahsa, Al-Jouf, Al-Qaisumah, and Wadi Al-Dawaser stations, respectively. It is found that the Abha site yields the highest solar PV energy among the five sites considered.

  45. 28.  Silicone oil impregnated nano silica modified glass surface and influence of environmental dust particles on optical transmittance
  46. JOURNAL PAPERSBS Yilbas, MR Yousaf, A Al-Sharafi, H Ali, FA Al-Sulaiman - RSC Advances, 2017


    The behavior of environmental dust particles on a silicone oil impregnated glass surface is examined in relation to optical transparent surfaces for self-cleaning applications. The characteristics of environmental dust, collected in the local area, are analyzed using analytical tools. Functional silica particles are synthesized and deposited on the glass surface prior to silicone oil impregnation. Optical properties of functionalized silica particle deposited glass surfaces are examined prior to and after oil impregnation. Further tests are conducted in the open environment to assess dust settlement in silicone oil and dust particle sedimentation on the glass surface. It is found that dust particles have various sizes and shapes, and they are composed of various metallic, alkaline, and alkaline earth metallic compounds. The average size of the dust particles is of the order of 1.2 μm. Silicone oil impregnation considerably improves the optical transmittance of functionalized silica particle deposited glass. A high spreading rate gives rise to a cloaking of dust particles on the oil surface, which gradually reduces the surface tension force and modifies the vertical force balance. Consequently, dust particles immerse into the oil film and sediment on the glass surface. This, in turn, lowers the optical transmittance of the oil impregnated glass surfaces greatly.

  47. Experimental investigation of a bubble column humidifier heated through solar energy


    An experimental study was carried out to assess the performance of a novel bubble column humidifier operated through solar thermal energy. Different perforated plate geometries were studied experimentally to select the optimum design that delivers a low overall pressure drop in the system. Then, the day-round performance of the humidifier was investigated experimentally with and without Fresnel lens. The influence of the air superficial velocity, inlet water temperature, and inlet air relative humidity on the performance of the humidifier were investigated. Findings indicate that the average daily absolute humidity of the air at the exit of the humidifier increased by 12.3% when the air superficial velocity increased from 20 to 30 cm s–1. This absolute humidity is further increased in the range of 9%–11% with the integration of the Fresnel lens. The new humidifier design can have a direct concentrated solar thermal heating and it acts as a heater for the water and air at the same time. Subsequently, it has high performance and it can be located in remote areas.


    The accumulation of dust and subsequent mud formation on solid surfaces in the humid environment adversely affects the optical, texture and mechanical properties of solid surfaces. The aim of this study was to provide a comprehensive analysis of environmental dust and dried mud and their impact on protective transparent covers of PV modules. Polycarbonate wafers and glass have been used as protective covers for PV modules. The dust has been collected from PV modules in the area of Dhahran, Kingdom of Saudi Arabia. Morphological and elemental analyses of the collected dust have been performed using Scanning Electron Microscopy-Energy-Dispersive Spectroscopy (SEM-EDS), while the particle size distribution has been analyzed using Dynamic Light Scattering (DLS) method. Qualitative analysis using Fourier Transform Infrared Spectroscopy (FTIR) has been conducted to determine the major and minor constituent minerals present in the dust sample. Mud solution has been prepared by suspending dust particles in deionized water which is then sprayed on transparent glass and polycarbonate substrates. The dried mud film has been analyzed employing SEM-EDS, X-ray diffraction, and UV–visible spectroscopy. Microtribometer analysis performed on dried mud films demonstrates that the tangential force required to remove the dry mud from glass substrate is comparatively higher as compared to that needed for the polycarbonate substrate.

  49. Superhydrophobic surfaces with antireflection properties for solar applications: A critical review
  50. JOURNAL PAPERSU Mehmood, FA Al-Sulaiman, BS Yilbas, B Salhi… - Solar Energy Materials and Solar Cells, 2016


    Antireflective surfaces with superhydrophobic characteristics are of considerable current interest owing to their potential utility in solving key technological problems. Superhydrophobic surfaces possess self-cleaning characteristics due to their unique surface texture and chemistry, which control wettability. The surface micro/nano texturing combined with low surface energy of materials lead to enhance anti-wetting properties. Self-cleaning surfaces exhibit special anti-wetting properties owing to the water contact angle greater than 150° leading to the ready rolling-off of water droplets. The surfaces can be made hydrophobic using two key pathways: i) making a rough surface from a low surface energy material, and ii) making a rough surface and modifying it with material of low surface energy. Similarly, transparent surface coatings with suitable optical path differences can suppress reflection from surfaces. High transparency is crucial in improving the performance of optical equipment and devices, such as windows, lenses, solar panels, etc. A normal solar panel absorbs only about 25% of the incident solar radiation, the remainder being reflected. Design and implementation of transparent super hydrophobic surfaces that repel atmospheric dust from solar panels, and thus reduce reflectivity of the surfaces are thus highly desirable. In this review, recent developments in antireflective, transparent, and superhydrophobic surfaces, with particular emphasis on glass and polymer materials, are highlighted. The review contains four sections as follows: (i) brief description of the basic concepts and principles of antireflection and self-cleaning; (ii) detailed fabrication pathways and their mechanisms; (iii) challenges faced in practical applications; and (iv) trends of future developments. Overall, a comprehensive overview of antireflective surfaces with superhydrophobic characteristics is provided in light of the current challenges.


    The overall objective of this study is to enhance the power conversion efficiency of dye-sensitized solar cells (DSSCs) by employing nanocomposite photoanodes. Nanocomposites of TiO2 with ZnO were synthesized by impregnation method. ZnO nanoparticles were impregnated on TiO2 in different concentrations and then characterized by Brunauer–Emmett–Teller (BET), X-ray powder diffraction (XRD) and scanning electron microscopy- energy-dispersive X-ray (SEM-EDX) analyses. Thin film photoanodes were prepared using composite paste with poly(vinylpyrrolidone) as a binder. Solar cells fabricated with ZnO/TiO2 nanocomposites photoanodes were characterized by photocurrent–voltage characteristic, Incident photon-to-current efficiency, and electrochemical impedance spectroscopy measurements. The results show that the DSSC based on ZnO/TiO2 film with an optimum concentration of ZnO (3 wt%) shows power conversion efficiency of 8.10%, improved by 28% compared to that of pure TiO2 based solar cell. The increase in efficiency can be attributed to fast electron transport, improve light harvesting efficiency, and enhanced electron collection at photoanodes.

  51. A review on current status and challenges of inorganic phase change materials for thermal energy storage systems
  52. JOURNAL PAPERSSA Mohamed, FA Al-Sulaiman, NI Ibrahim, MH Zahir… - Renewable and Sustainable Energy Reviews, 2016


    Latent heat energy storage system is one of the promising solutions for efficient way of storing excess thermal energy during low consumption periods. One of the challenges for latent heat storage systems is the proper selection of the phase change materials (PCMs) for the targeted applications. As compared to organic PCMs, inorganic PCMs have some drawbacks, such as corrosion potential and phase separation; however, there are available techniques to overcome or minimize these drawbacks. On the other hand, inorganic PCMs are found to have higher thermal conductivity and storage capacity over organic PCMs. As a result inorganic PCMs have a great potential in thermal energy storage field, especially in medium to high temperature applications where organic PCMs are not a viable option. In this study, a detailed review of research outcomes and recent technological advancements in the field of inorganic phase change materials is presented while focusing on providing solutions to the associated disadvantages of this class of PCMs. Long term stability, thermal cycling performance, and heat transfer enhancements are also discussed in the context of this review.

  53. A review on supercooling of Phase Change Materials in thermal energy storage systems
  54. JOURNAL PAPERSA Safari, R Saidur, FA Sulaiman, Y Xu, J Dong - Renewable and Sustainable Energy Reviews, 2016


    Thermal energy storage is at the height of its popularity to harvest, store, and save energy for short-term or long-term use in new energy generation systems. It is forecasted that the global thermal energy storage market for 2015–2019 will cross US$1,300 million in revenue, where the highest growth is expected to be in Europe, Middle East, and Africa followed by Asia-Pacific region. Thermal energy storage has become an inevitable component of fluctuant renewable energy systems due to their significant role in increasing efficiency and Quality of Service (QoS).
    Currently, one major research stream in such systems is improving the efficiency of heat exchangers and heat carriers. Hence, studying thermal behavior and thermophysical properties of heat storages is of great importance. In this study, we review a common but not very well-known problem of supercooling of Phase Change Materials (PCM). Supercooling is a thermophysical property of PCMs that is problematic in thermal storage applications. This review looks at supercooling from another point of view and investigates applications (such as specialized thermal storage applications) that can put supercooling into operation. To achieve this, development of techniques to increase state stability and designing reliable and stable supercooled heat storage systems will be investigated. The study will look at the thermal energy storage of supercooled liquids, degree and measurement of supercooling. Furthermore, factors that influence degree of supercooling and their effect on output capacity will be discussed. It looks at the supercooled material in four major categories and looks into the mechanisms for triggering crystallization in supercooled liquids. Applications including solar thermal storage will be the discussed in details. From the results discussed in this review researchers will identify and gain insight into supercooling control techniques, which are necessary for developing efficient heat exchangers, and also essential for promoting adoption of sustainable renewable energies.

  55. Surface Characteristics of Silicon Nanowires/Nanowalls Subjected to Octadecyltrichlorosilane Deposition and n-octadecane Coating
  56. JOURNAL PAPERSBS Yilbas, B Salhi, MR Yousaf, Al-Sulaiman, H Ali… - Nature Scientific reports, 2016


    In this study, nanowires/nanowalls were generated on a silicon wafer through a chemical etching method. Octadecyltrichlorosilane (OTS) was deposited onto the nanowire/nanowall surfaces to alter their hydrophobicity. The hydrophobic characteristics of the surfaces were further modified via a 1.5-μm-thick layer of n-octadecane coating on the OTS-deposited surface. The hydrophobic characteristics of the resulting surfaces were assessed using the sessile water droplet method. Scratch and ultraviolet (UV)-visible reflectivity tests were conducted to measure the friction coefficient and reflectivity of the surfaces. The nanowires formed were normal to the surface and uniformly extended 10.5 μm to the wafer surface. The OTS coating enhanced the hydrophobic state of the surface, and the water contact angle increased from 27° to 165°. The n-octadecane coating formed on the OTS-deposited nanowires/nanowalls altered the hydrophobic state of the surface. This study provides the first demonstration that the surface wetting characteristics change from hydrophobic to hydrophilic after melting of the n-octadecane coating. In addition, this change is reversible; i.e., the hydrophilic surface becomes hydrophobic after the n-octadecane coating solidifies at the surface, and the process again occurs in the opposite direction after the n-octadecane coating melts.


    A performance assessment of sizing an auxiliary boiler for a solar driven supercritical double recompression CO2 Brayton cycle was conducted. The Brayton cycle is designed to deliver three different power outputs and the required size of the auxiliary boiler was examined in detail. The heat fraction to be delivered from the solar field and from the auxiliary boiler for each month of the year are reported. Furthermore, the daytime solar multiple and the twenty-four hour solar multiple were examined. Another key parameter that was studied is the effect of the turbine inlet temperature on the net power, energy efficiency, and exergy efficiency. Among the other exergy parameters that were examined are exergy destruction, exergy improvement potential, fuel depletion ratio, relative irreversibility, and productivity lack. The power output for Case 1, Case 2, and Case 3 is about 41.5 MW, 60.0 MW, and 90.0 MW, respectively; and for the month of June, the fraction of the heat from the auxiliary boiler during daytime hours is about 0.25, 0.40, and 0.54, respectively. For the three Cases the overall system energy efficiency during the month of June is 20.7%, 25.0%, 29.6%, and the overall system exergy efficiency is 22.2%, 28.3%, and 35.7%, respectively. The cycle efficiency is about 47% for the baseline conditions. In addition, the lowest thermal heat collected in the receiver is during December and, therefore, during this month, the highest auxiliary heat is required from the boiler. The 24-h average solar multiple for Case 1, Case 2, and Case 3 is 0.437, 0.303, and 0.202, respectively; and the average daytime solar multiple for these cases is 0.858, 0.590, and 0.396, respectively. Moreover, similar results are reported for each month of the year. Furthermore, the findings demonstrate that the heliostat has the highest exergy destruction rate and, thus, it has the highest exergy improvement potential.

  57. Nanowires: a new pathway to nanotechnology-based applications
  58. JOURNAL PAPERSB Salhi, MK Hossain, AW Mukhaimer, FA Al-Sulaiman - Journal of Electroceramics, 2016


    The synthesis and the characterisation of silicon nanowires (SiNWs) have recently attracted great attention due to their potential applications in electronics and photonics. As yet, there are no practical uses of nanowires, except for research purposes, but certain properties and characteristics of nanowires look very promising for the future.

  59. An experimental investigation of a novel design air humidifier using direct solar thermal heating
  60. JOURNAL PAPERSHM Abd-ur-Rehman, FA Al-Sulaiman - Energy Conversion and Management, 2016


    In this study, a novel solar heated multi-stage bubble column humidifier is designed and tested. The overall objective of this work is to investigate the main operating parameters of the new humidifier. The study addresses the significance of the perforated plate geometric features, optimum balance of air superficial velocity and water column height, and the influence of inlet water temperature and inlet air relative humidity on the performance of the humidifier. The day round performance of the humidifier is investigated in single stage, two stage, and three stage configuration, in which each configuration was tested with and without the integration of the Fresnel lens. Findings show that the average day round absolute humidity, without Fresnel lens, increased up to 9% for the two stage configuration and 23% for the three stage configuration as compared to the single stage configuration of the humidifier. The integration of the Fresnel lens further increased the absolute humidity up to 25% as compared to the results obtained without the integration of the Fresnel lens under the same prevailing conditions, which is significant. Moreover, the current humidifier shows a higher humidification efficiency in the climatic conditions that have a lower inlet air relative humidity. Furthermore, the finding demonstrates that the newly developed multi-stage bubble column humidifier has better performance as compared to the conventional single stage bubble column humidifier. The findings from this study are of pivotal importance to understand the optimum operating conditions of the humidifier for its possible integration with the dehumidifier. Consequently, an improved humidification-dehumidification desalination system attained.

  61. Performance assessment of water production from solar cooling system in humid climate
  62. JOURNAL PAPERSNI Ibrahim, FA Al-Sulaiman, R Saidur - Energy Conversion and Management, 2016


    This study aims to investigate water extraction process from a solar cooling system using a vapor absorption chiller under variable fresh air ratios. The system consists of an evacuated tube solar collector, lithium bromide absorption chiller and a fan coil unit (FCU). A parametric study is carried out to investigate the effects of flow rate of the fluid in the collector, solar insolation, fresh air volume ratio, temperature and humidity on the system performance and rate of water production. The operating conditions for the best performance are identified in this work. The results showed maximum collector efficiency of 0.66 at an optimum flow rate of the collector fluid of 0.3 kg/s at Ac = 28 m2, Tf = 45 °C, I = 800 W/m2 and R = 50%. For the same conditions, useful energy to the generator was found to be 14.8 kW and water production rate was 8 L/h. Using the climate data of a typical day of August for Dhahran, Saudi Arabia, the findings indicated that the chiller COP and water production rate, respectively, reached maximum (0.73 and 6.6 L/h) at noon when the incident solar flux is peak (935 W/m2) for 45% fresh air volume ratio.

  63. Performance assessment of a solar powered ammonia–water absorption refrigeration system with storage units
  64. JOURNAL PAPERSMMA Khan, NI Ibrahim, R Saidur, IM Mahbubul, FA Al-Sulaiman - Energy Conversion and Management, 2016


    Solar thermal energy is one of the viable options for space cooling in the quest of greener environment and energy efficiency. The major challenge in actualizing the use of solar energy to drive cooling systems such as absorption chillers is its intermittent nature, thereby not able to cover significantly the period of cooling demand in most situations. In order to achieve continuous cooling energy supply from solar driven absorption chillers, the present study considered two alternative storage units in the form of chilled water and ice, integrated to the main chiller installed in Dhahran, Saudi Arabia. The system is designed to allow different operational modes in accordance with the cooling demands. The system is tested experimentally where the storage units are used alternatively and the results are presented. A mean chiller COP for cooling the space and chilling the water was found to be 0.8 whereas it was 1.3 for only making ice. Maximum COP (0.8) was found at Tgen = 120 °C at an average condenser and evaporator temperatures of 34.5 °C and −2.2 °C, respectively.

  65. Fabrication and optical simulation of vertically aligned silicon nanowires
  66. JOURNAL PAPERSMK Hossain, B Salhi, AW Mukhaimer, FA Al-Sulaiman - Applied Nanoscience, 2016


    Silicon nanowires (Si-NWs) have been considered widely as a perfect light absorber with strong evidence of enhanced optical functionalities. Here we report finite-difference time-domain simulations for Si-NWs to elucidate the key factors that determine enhanced light absorption, energy flow behavior, electric field profile, and excitons generation rate distribution. To avoid further complexity, a single Si-NW of cylindrical shape was modeled on c-Si and optimized to elucidate the aforementioned characteristics. Light absorption and energy flow distribution confirmed that Si-NW facilitates to confine photon absorption of several orders of enhancement whereas the energy flow is also distributed along the wire itself. With reference to electric field and excitons generation distribution it was revealed that Si-NW possesses the sites of strongest field distributions compared to those of flat silicon wafer. To realize the potential of Si-NWs-based thin film solar cell, a simple process was adopted to acquire vertically aligned Si-NWs grown on c-Si wafer. Further topographic characterizations were conducted through scanning electron microscope and tunneling electron microscope-coupled energy-dispersive spectroscopy.


    The aim of this work is to evaluate the optimum selection criteria for domestic solar water heating (SWH) systems based on the techno-economic aspects of evacuated tube and glazed flat plat solar collectors. Ten different cities in Saudi Arabia are considered. Choices were made to cover different geographical co-ordinates of Saudi Arabia under different climatic conditions. Simulations were performed to obtain at least 50% solar fraction and the rest of the need was fulfilled by electricity. Simulated results based on solar radiation on the horizontal and tilted surface, solar fraction, greenhouse gas (GHG) emissions, and energy savings are used for comparative performance analysis of the SWH systems while payback period, benefit to cost ratio, annual life cycle savings, and number of occupants are the deciding factors for economic viability of these systems. Findings indicate that under the same prevailing conditions Nejran, Bisha, and Madina are the most feasible cities while Sulayyil is the least suitable place for SWH system. Riyadh, Dhahran, and Gaseem show noticeable financial advantages by using evacuated tube collectors over glazed flat plate collectors. The findings demonstrate that a higher number of occupants gives a lower payback period and a higher benefit to cost ratio; as long as the number of collectors are not increased to a limit where higher initial cost dominates and decreases the economic viability of the project.


    A segmented thermoelectric generator and thermal performance of the device is investigated in terms of the efficiency of the device and its output power. The influence of tapering of the device pins on the segmented thermoelectric performance is also analyzed. Modified Bismuth and lead tellurides are used as the pin materials. The performance characteristics of the segmented thermoelectric generator are compared with its counterpart, which has homogeneous material pin configurations. Various levels of the load and temperature ratios are incorporated to assess the performance of the device. The findings reveal that the segmented thermoelectric generator results in a higher efficiency and more output power than those with the homogeneous configurations. The shape factor, defining the pin tapering, influences the device efficiency significantly; in which case, increasing the shape factor enhances the device efficiency. The opposite is true for the device output power; in which case, the pin tapering lowers the device output power.

  67. Entropy, exergy, and cost analyses of solar driven cogeneration systems using supercritical CO 2 Brayton cycles and MEE-TVC desalination system
  68. JOURNAL PAPERSA Kouta, FA Al-Sulaiman , M Atif, SB Marshad - Energy Conversion and Management, 2016


    In this study, performance and cost analyses are conducted for a solar power tower integrated with supercritical CO2 (sCO2) Brayton cycles for power production and a multiple effect evaporation with a thermal vapor compression (MEE-TVC) desalination system for water production. The study is performed for two configurations based on two different supercritical cycles: the regeneration and recompression sCO2 Brayton cycles. A two-tank molten salt storage is utilized to ensure a uniform operation throughout the day. From the entropy analysis, it was shown that the solar tower is the largest contributor to entropy generation in both configurations, reaching almost 80% from the total entropy generation, followed by the MEE-TVC desalination system, and the sCO2 power cycle. The entropy generation in the two-tank thermal storage is negligible, around 0.3% from the total generation. In the MEE-TVC system the highest contributing component is the steam jet ejector, which is varying between 50% and 60% for different number of effects. The specific entropy generation in the MEE-TVC decreases as the fraction of the input heat to the desalination system decreases; while the specific entropy generation of the sCO2 cycle remains constant. The cost analysis performed for different regions in Saudi Arabia and the findings reveal that the regions characterized by the highest average solar irradiation throughout the year have the lowest LCOE and LCOW values. The region achieving the lowest cost is Yanbu, followed by Khabt Al-Ghusn in the second place, and the rest are as follows, Jabal Al-Rughamah, Jizan, Al-Khafji, and Dhahran. The LCOE of Yanbu at a fraction of 0.5 for the regeneration and recompression solar cogeneration cycles are 0.0915 $/kW h and 0.0826 $/kW h, respectively.

  69. Influence of thermalcapillary and buoyant forces on flow characteristics in a droplet on hydrophobic surface
  70. JOURNAL PAPERSA Al-Sharafi, H Ali, BS Yilbas, AZ Sahin, M Khaled, FA Al-Sulaiman - International Journal of Thermal Sciences, 2016


    Wetting characteristics of droplets on hydrophobic surfaces are the current interest in many fields because of necessity for self-cleaning, improving lubrication, speedy liquid separation, bacterial activity minimization, reducing fouling, etc. Therefore, we investigate flow and thermal fields in a droplet at a hydrophobic surface due to a localized heating and analyze the effects of droplet contact angle on heat and flow characteristics due to thermocapillary and buoyancy forces developed in the droplet. Trichlorooctadecylsilane coating is introduced on a smooth polycarbonate wafer to generate a hydrophobic surface and a fine sized metallic meshes is laid on the hydrophobic surface where a constant temperature heating is applied at 308 K. Flow filed is simulated numerically incorporating the experimental conditions. A droplet of a nano-fluid, consisting of water and 1% (volume) carbon nanotube mixture, is formed at the hydrophobic surface to monitor the flow velocity in the droplet, which is, then, used for the validation of velocity predictions. It is found that combination of Marangoni and buoyancy forces give rise to formation of circulation cells inside the droplet; in which case, contact angles in the range of 110° ≤ θ ≤ 150° two counter rotating circulation cells are formed in the upper part of the droplet. The average Nusselt number increases with increasing droplet contact angle.


    The performance of building integrated photovoltaic modules (PV) situated outdoors suffers from attained high temperatures due to irradiation as a negative temperature coefficient of their efficiency. Phase change materials (PCMs) are investigated as an option to manage the thermal regulation of photovoltaic modules and, hence, enhance their electrical efficiency. In this study a transient one-dimensional energy balance model has been developed to investigate the thermal performance of a photovoltaic module integrated with PCM storage system. Possible all heat transfer mechanisms are described to have a basic and step by step fundamental knowledge to analyze and understand the complex heat transfer characteristics of the PV-PCM system. Finite difference scheme is applied to discretize the energy balance equation while fully implicit scheme is applied to discretize the heat balance in the PCM module. Three different PCM of different melting temperatures were investigated. The numerical result is validated with experimental studies from the literature. The result indicates that PCM are shown to be an effective means of limiting the temperature rise in the PV devices thus increasing the thermal performance up to 5%.

  71. Laser gas assisted texturing of alumina surfaces and effects of environmental dry mud solution on surface characteristics
  72. JOURNAL PAPERSBS Yilbas, H Ali, M Khaled, N Al-Aqeeli, FA Al-Sulaiman - Ceramics International, 2016


    High pressure nitrogen gas assisted laser texturing of alumina surface is carried out and the effects of dust accumulation and mud formation on the surface characteristics are examined. The dust accumulation and mud formation is simulated in the laboratory environments in line with the local environmental conditions. Morphological and metallurgical changes in the laser treated region are examined using scanning electron and atomic force microscopes, energy dispersive spectroscopy, and X-ray diffraction. Surface microhardness is measured and residual stress formed in the surface region is determined from the X-ray diffraction data. Surface hydrophobicity is assessed through the contact angle measurements. Scratch tests are incorporated to measure the friction coefficient of the laser treated and as received workpiece surfaces. It is found that laser texturing results in superhyrophobic surface and the formation of AlN compounds at the textured surface lowers the surface energy while contributing to the surface hydrophobicity enhancement. The mud solution modifies the surface texture characteristics of the laser treated workpieces; in which case, surface hydrophobicity reduces significantly. Surface hardness increases considerably after the laser treatment process because of grain refinement under high cooling rates and volume shrinkage due to AlN compound formation in the surface region. Residual stress is compressive in the surface region of the laser textured workpiece and the mud solution increases slightly surface hardness and residual stress in the surface region.


    In this paper a parametric study is conducted to investigate the effect of influencing operating variables on cooling to power ratio and exergy efficiency of the solar based cogeneration cycle. The results indicate that both energy and exergy efficiencies of the cogeneration increases by less than a percent while cooling to power ratio reduces by 33% when the direct normal irradiation (DNI) rises from 800 W/m² to 975 W/m². The energy efficiency (EUF) and exergy efficiency vary from 28.43% to 32.82% and 16.67% to 15.66%, respectively, when turbine back pressure increased from 0.3 MPa to 0.475 MPa. The EUF and cooling to power ratio vary from 31.15% to 43.66% and 1.3 to 2.25, respectively, with a rise in evaporator temperature from 4°C to 11°C. It is indicated that around 83.97% of the input solar exergy is destroyed owing to irreversibilities in the components and via energy transfers through the condenser and drain water.

  73. Electrochemical impedance spectroscopy and photovoltaic analyses of dye-sensitized solar cells based on carbon/TiO2 composite counter electrode
  74. JOURNAL PAPERSU Mehmood, HZ Aslam, FA Al-Sulaiman, A Al-Ahmed… - Journal of The Electrochemical Society, 2016


    The objective of this study is to replace the platinum catalyst normally used in the counter electrode of dye-sensitized solar cells by a low cost activated carbon (AC)/TiO2 nanocomposite. The counter electrodes were prepared by varying the composition of activated carbon (AC) in the AC/TiO2 nanocomposites. The TiO2 anatase paste was used as a binder to hold the carbon nanoparticles together. The morphological properties of composite counter electrodes were analyzed by scanning electron microscope. Solar cells with composite counter electrodes were characterized for photocurrent-voltage relation and electrochemical impedance spectroscopy measurements. The results indicate that the efficiency of solar cells is highly dependent on the concentration of activated carbon in the counter electrode. The optimal performance of the solar cell was observed for the counter electrode containing 10% activated carbon showing JSC = 15.834 mA cm−2, Voc = 700 mV, Rs = 49 Ω, FF = 55, and η = 6.04%. These photovoltaic parameters are comparable with JSC = 14.638 mA cm−2, Voc = 810 mV, Rs = 43 Ω, FF = 60, and η = 7.0% for the platinum based dye sensitized solar cell.

  75. Experimental and numerical performance analysis of a converging channel heat exchanger for PV cooling
  76. JOURNAL PAPERSAAB Baloch, HMS Bahaidarah, P Gandhidasan, FA Al-Sulaiman… - Energy Conversion and Management, 2015


    An experimental and numerical investigation of a cooling technique called as converging channel cooling intended to achieve low and uniform temperature on the surface of PV panel is presented in this paper. Experimental evaluation for an uncooled PV system and a converging channel cooled PV system was carried out subjected to the hot climate of Saudi Arabia for the month of June and December. Detailed modeling was performed using numerical analysis to investigate the effect of changing the converging angle on the thermal characteristics of the PV system. Based on the developed model, two degrees angle showed the best performance in terms of temperature distribution and average cell temperature with a standard deviation of 0.91 °C. A comprehensive system model was developed to assess the performance of PV systems numerically by coupling the optical, radiation, thermal, computational fluid dynamics, and electrical model. Thermal measurements for an uncooled PV showed cell temperature as high as 71.2 °C and 48.3 °C for the month of June and December, respectively. By employing converging cooling, cell temperature was reduced significantly to 45.1 °C for June and to 36.4 °C for December. Maximum percentage improvement in power output was 35.5% whereas maximum percentage increase in the conversion efficiency was 36.1% when compared to the performance of an uncooled PV system. For cost feasibility of an uncooled and cooled PV system, levelized cost of energy (LCE) analysis was performed using the annual energy yield simulation for both systems. LCE was found to be 1.95(€/kW h) for an uncooled PV system which was reduced to 1.57(€/kW h) for converging cooled PV system with a relative percentage decrease of 19.5%, hence making it economically viable.

  77. Supercritical Carbon Dioxide Brayton Cycles Driven by Solar Thermal Power Tower System
  78. JOURNAL PAPERSM Atif, FA Al-Sulaiman - Advanced Materials Research, 2015


    This chapter starts with a background about concentrating solar power systems and thermal energy storage systems and then a detailed literature review about concentrated solar power systems and supercritical Brayton carbon dioxide cycles. Next, a mathematical model was developed and presented which generates and optimizes a heliostat field effectively. This model was developed to demonstrate the optimization of a heliostat field using differential evolution, which is an evolutionary algorithm. The current model illustrates how to employ the developed model and its advantages. The optimization process calculates the optical performance parameters at every step of the optimization considering all the heliostats; thus yields accurate results as discussed in this chapter. On the other hand, complete mathematical model of supercritical CO2 Brayton cycles when integrated with solar thermal power tower system was presented and discussed.

  79. Development of a mathematical model for optimizing a heliostat field layout using differential evolution method
  80. JOURNAL PAPERSM Atif, FA Al‐Sulaiman - International Journal of Energy Research, 2015


    In this study, differential evolution was employed to perform optimization of a heliostat field. A complete mathematical code was developed for this purpose, which generates a heliostat field and calculates the optimum spacing between heliostats through differential evolution optimization technique. The optimization was executed for two sets of two cases and compared with an un-optimized case. In the first case, only the optical performance was optimized, whereas in the second case, the normalized ratio of the optical performance to the land area covered by the heliostat field was maximized. In the first set of cases, the extra security distance between the heliostats was neglected, whereas in the second set of cases, the extra security distance was taken into account. To apply and examine the application of the optimization algorithm developed, 3 days of the year were selected: March 21, June 21, and December 21, considering Dhahran, Saudi Arabia as an illustrative example. For June 21, when the extra security distance between the heliostats is neglected, the optical efficiency of the un-optimized case was 0.6026, while for the first optimized case, it was 0.6395, and for the second optimized case, it was 0.6033. However, when the extra security distance was considered, the optical efficiency of the un-optimized case was 0.6167; while for the first optimized case, it was 0.6241, and for the second optimized case, it was 0.6167. Similar observations were realized for the other cases selected. Copyright © 2015 John Wiley & Sons, Ltd.

  81. Thermoeconomic analysis of shrouded wind turbines
  82. JOURNAL PAPERSFA Al-Sulaiman, BS Yilbas - Energy Conversion and Management, 2015


    In this study, thermoeconomic analysis of shrouded wind turbines is conduced incorporating different area ratios of the shroud. Key thermoeconomic parameters are examined which include, cost of the power produced, cost of the exergy lost, exergy efficiency, exergetic improvement potential, air mass flow rate through the wind turbine, and power produced. It was concluded that the wind turbine performance improved as the shroud area ratio increased. Consequently, the cost of the power produced became low for the case of high area ratio and vice-versa. It was demonstrated that the cost was significantly high under low wind speed. The same finding was observed for the cost rate of the exergy loss in which the cost was the lowest for the highest area ratio value considered in the present study. The findings also showed that the exergetic improvement potential increased as the wind speed increased and exergetic improvement potential enhanced further at high shroud area ratio.


    Optimization of a heliostat field is an essential task to make a solar central receiver system effective because major optical losses are associated with the heliostat fields. In this study, a mathematical model was developed to effectively optimize the heliostat field on annual basis using differential evolution, which is an evolutionary algorithm. The heliostat field layout optimization is based on the calculation of five optical performance parameters: the mirror or the heliostat reflectivity, the cosine factor, the atmospheric attenuation factor, the shadowing and blocking factor, and the intercept factor. This model calculates all the aforementioned performance parameters at every stage of the optimization, until the best heliostat field layout based on annual performance is obtained. Two different approaches were undertaken to optimize the heliostat field layout: one with optimizing insolation weighted annual efficiency and the other with optimizing the un-weighted annual efficiency. Moreover, an alternate approach was also proposed to efficiently optimize the heliostat field in which the number of computational time steps was considerably reduced. It was observed that the daily averaged annual optical efficiency was calculated to be 0.5023 as compared to the monthly averaged annual optical efficiency, 0.5025. Moreover, the insolation weighted daily averaged annual efficiency of the heliostat field was 0.5634 for Dhahran, Saudi Arabia. The code developed can be used for any other selected location.


    In this study, a thermodynamic comparison of five supercritical carbon dioxide Brayton cycles integrated with a solar power tower was conducted. The Brayton cycles analyzed were simple Brayton cycle, regenerative Brayton cycle, recompression Brayton cycle, pre-compression Brayton cycle, and split expansion Brayton cycle. A complete mathematical code was developed to carry out the analysis. A heliostat field layout was generated and then optimized on an annual basis using the differential evolution method, which is an evolutionary algorithm. The heliostat field was optimized for optical performance and then integrated with the supercritical CO2 Brayton cycles. Using the results of the optimization, a comparison of net power outputs and thermal efficiencies for these cycles was performed. The findings demonstrated that the highest thermal efficiency was achieved using the recompression Brayton cycle, at June noontime. The maximum integrated system thermal efficiency using this cycle was 40% while the maximum thermal efficiency of this cycle alone was 52%. The regenerative Brayton cycle, although simpler in configuration, shows comparable performance to the recompression Brayton cycle. This analysis was carried out for Dhahran, Saudi Arabia.


    Integrating solar thermal technologies with gas turbine cogeneration plants reduces fuel consumption and consequently results in a considerable reduction in gas emissions. These technologies are expected to play an important role in solving the global environmental and energy problems. The present work provides a detailed investigation of the technical and economic feasibility of integrating a Parabolic Trough Collector (PTC) system with gas turbine cogeneration system. In this regard, different generating capacities of gas turbine and areas of solar collectors have been examined and presented for a hybrid solar gas turbine cogeneration system that produces electricity and process steam at a rate of 81.44 kg/s at 394 °C and 45.88 bar. Thermoflex with PEACE simulation software has been used to assess the performance of each proposed integration design option. Optimum solar field size for each considered gas turbine generating capacity (size) has been identified. Also, the reduction in CO2 emissions due to the integration of PTC systems has been calculated as percentage of the CO2 emissions from the conventional system for each gas turbine generating capacity size. The results indicated that hybrid solar gas turbine cogeneration systems with gas turbine generating capacities less than 90 MWe demonstrate a negligible increase in the levelized electricity cost (LEC), which was between 5 US ¢ ¢ and 10 US ¢ ¢/kW h. It was demonstrated also that integrating a PTC system with a gas turbine cogeneration system of less than 110 MWe generating capacity has more economic feasibility compared to CO2 capturing technologies.

  83. Humidification dehumidification desalination system using parabolic trough solar air collector
  84. JOURNAL PAPERSFA Al-Sulaiman, MI Zubair, M Atif, P Gandhidasan… - Applied Thermal Engineering, 2015


    This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity.

  85. Techno-economic performance analysis of parabolic trough collector in Dhahran, Saudi Arabia
  86. JOURNAL PAPERSEMA Mokheimer, YN Dabwan, MA Habib, SAM Said, FA Al-Sulaiman - Energy Conversion and Management, 2014


    The main criteria to assess a new solar thermal power plant are its performance and cost. Therefore, there is a need to present to the open literature a detailed modeling procedure and cost analyses to help researchers, engineers, and decision makers. The main objectives of this work are to develop a code and to evaluate the optical and thermal efficiencies of parabolic trough collectors (PTCs) solar field considering average hourly, daily, monthly, or annually averaged weather data; in addition to detailed cost analysis of the solar field. In this regard, a computer simulation code was developed using Engineering Equations Solver (EES). This simulation code was validated against Thermoflex code and data previously published in the public literature, and excellent agreements ware observed. The types of the PTC considered in the simulation are EuroTrough solar collector (ET-100) and for LUZ solar collector LS-3. The present study revealed that the maximum optical efficiency that can be reached in Dhahran is 73.5%, whereas the minimum optical efficiency is 61%. This study showed also that the specific cost for a PTC field per unit aperture area and the specific cost of different mechanical works can be cut by about 46% and 48% at 10 hectare and by about 72% and 75% at 160 hectare, respectively, compared to that at 2.8 hectare. On the other hand, the specific civil costs remain constant independent of the plant size. It was found that the ratio of the cost of the PTC to the solar field area decreases significantly as the solar field size increases. This decrement is very significant until the solar field size reaches 60 hectare and then the slope of the decrement is becoming insignificant. Therefore, it is recommended to have a solar field size of 60 hectare or larger.


    In this paper, detailed exergy analysis of selected thermal power systems driven by parabolic trough solar collectors (PTSCs) is presented. The power is produced using either a steam Rankine cycle (SRC) or a combined cycle, in which the SRC is the topping cycle and an organic Rankine cycle (ORC) is the bottoming cycle. Seven refrigerants for the ORC were examined: R134a, R152a, R290, R407c, R600, R600a, and ammonia. Key exergetic parameters were examined: exergetic efficiency, exergy destruction rate, fuel depletion ratio, irreversibility ratio, and improvement potential. For all the cases considered it was revealed that as the solar irradiation increases, the exergetic efficiency increases. Among the combined cycles examined, the R134a combined cycle demonstrates the best exergetic performance with a maximum exergetic efficiency of 26% followed by the R152a combined cycle with an exergetic efficiency of 25%. Alternatively, the R600a combined cycle has the lowest exergetic efficiency, 20–21%. This study reveals that the main source of exergy destruction is the solar collector where more than 50% of inlet exergy is destructed, or in other words more than 70% of the total destructed exergy. In addition, more than 13% of the inlet exergy is destructed in the evaporator which is equivalent to around 19% of the destructed exergy. Finally, this study reveals that there is an exergetic improvement potential of 75% in the systems considered.


    In this study, solar field sizing and overall performance of different vapor cycles are examined. The systems considered are parabolic trough solar collectors integrated with either a binary vapor cycle or a steam Rankine cycle (SRC). The binary vapor cycle consists of an SRC as a topping cycle and an organic Rankine cycle as a bottoming cycle. Seven refrigerants are examined for the bottoming cycle: R600, R600a, R134a, R152a, R290, R407c, and ammonia. This study reveals that significant reduction in the solar field size is gained due to the performance improvement when the binary vapor cycle is considered as compared to a steam Rankine cycle with atmospheric condensing pressure; however, SRC with vacuum pressure has the best performance and smallest solar field size. It further reveals that the R134a binary vapor cycle has the best performance among the binary vapor cycles considered and, thus, requires the smallest solar field size while the R600a binary vapor cycle has the lowest performance. Finally, optimization shows that lowering the mass flow rate of the heat transfer fluid (HTF) per each solar collector row, within the range considered, results in a reduction of the required number of solar collector rows and, thus, in savings.

  87. Thermoeconomic optimization of three trigeneration systems using organic Rankine cycles: Part II–Applications
  88. JOURNAL PAPERSFA Al-Sulaiman, I Dincer, F Hamdullahpur - Energy conversion and management, 2013


    In this part II of the study, three new trigeneration systems are examined. These systems are SOFC-trigeneration, biomass-trigeneration, and solar-trigeneration systems. This study reveals that the maximum trigeneration-exergy efficiencies are about 38% for the SOFC-trigeneration system, 28% for the biomass-trigeneration system and 18% for the solar-trigeneration system. Moreover, the maximum cost per exergy unit for the SOFC-trigeneration system is approximately 38 $/GJ, for the biomass-trigeneration system is 26 $/GJ, and for the solar-trigeneration system is 24 $/GJ. This study reveals that the solar-trigeneration system offers the best thermoeconomic performance among the three systems. This is because the solar-trigeneration system has the lowest cost per exergy unit. Furthermore, the solar-trigeneration system has zero CO2 emissions and it is based on a free renewable energy source.

  89. Thermoeconomic optimization of three trigeneration systems using organic Rankine cycles: Part I–Formulations
  90. JOURNAL PAPERSFA Al-Sulaiman, I Dincer, F Hamdullahpur - Energy Conversion and Management, 2013


    This part I of the study presents the thermoeconomic optimization formulations of three new trigeneration systems using organic Rankine cycle (ORC): SOFC-trigeneration, biomass-trigeneration, and solar-trigeneration systems. A thermoeconomic modeling is employed using the specific exergy costing (SPECO) method while the optimization performed using the Powell’s method to minimize the product cost of trigeneration (combined, cooling, heating, and power). The results help in understanding how to apply the thermoeconomic modeling and thermoeconomic optimization to a trigeneration system.


    In this study, exergy analysis of a novel desalination system is presented and discussed. The water desalination is carried out using combined humidification–dehumidification and reverse osmosis technologies. Six system performance parameters are examined: overall exergetic efficiency, equivalent electricity consumption, specific exergy destruction, specific exergy lost, and total true specific exergy lost, as well as the exergy destruction ratios of the main components. The total true specific exergy lost is a new parameter presented in this study. It is a function of summation of total the exergy destruction rate and loss per total mass flow rate of the total pure water produced. This parameter is found to be a useful parameter to assess the exergetic performance of the system considered. By contrast, use of overall exergetic efficiency as an assessment tool can result in misleading conclusions for such a desalination system and, hence, is not recommended. Furthermore, this study reveals that the highest exergy destruction occurs in the thermal vapor compressor, which accounts for 50% of the total exergy destruction of the system considered. This study, in addition, demonstrates that the specific exergy destruction of the dehumidifier and TVC are the parameters that most strongly affect the performance of the system.


    In this study, performance assessment of a novel system based on parabolic trough solar collectors and an organic Rankine cycle for combined cooling, heating and power (CCHP) is presented. In this system, a portion of the waste heat is used for heating through a heat exchanger and the other portion is used for cooling through a single-effect absorption chiller. This study considers three modes of operation: a solar mode, which is characterized by a low-solar radiation; a solar and storage mode, which is characterized by a high-solar radiation; and a storage mode, which is the operation of the system at night time through a thermal storage tank subsystem. To assess the performance improvement of the present system, three further cases are considered: electrical power, cooling-cogeneration, and heating-cogeneration. This system is designed to produce 500 kW of electricity. Different output parameters – efficiency, net electrical power, and electrical to heating and cooling ratios – are examined in this study. This study reveals that the maximum electrical efficiency for the solar mode is 15%, for the solar and storage mode is 7%, and for the storage mode is 6.5%. Alternatively, when CCHP is used, the efficiency increases significantly. The maximum CCHP efficiency for the solar mode is 94%, for the solar and storage mode is 47%, and for the storage mode is 42%. Furthermore, this study shows that the electrical to cooling ratio is sensitive to the change in the ORC pump inlet temperature. Therefore, the variation in this temperature could be used as a good control for the amount of the cooling power needed.

  91. Energy and exergy analyses of a biomass trigeneration system using an organic Rankine cycle
  92. JOURNAL PAPERSFA Al-Sulaiman, I Dincer, F Hamdullahpur - Energy, 2012


    In this study, energy and exergy analyses of a biomass trigeneration system using an organic Rankine cycle (ORC) are presented. Four cases are considered for analysis: electrical-power, cooling-cogeneration, heating-cogeneration and trigeneration cases. The results obtained reveal that the best performance of the trigeneration system considered can be obtained with the lowest ORC evaporator pinch temperature considered, Tpp = 20 K, and the lowest ORC minimum temperature, T9 = 345 K. In addition, this study reveals that there is a significant improvement when trigeneration is used as compared to only electrical power production. This study demonstrates that the fuel utilization efficiency increases, in average, from 12% for electrical power to 88% for trigeneration. Moreover, the maximum exergy efficiency of the ORC is 13% and, when trigeneration is used, it increases to 28%. Furthermore, this study reveals that the electrical to cooling ratio can be controlled through changing the ORC evaporator pinch point temperature and/or the pump inlet temperature. In addition, the study reveals that the biomass burner and the ORC evaporator are the main two sources of exergy destruction. The biomass burner contributes to 55% of the total destructed exergy whereas the ORC evaporator contributes to 38% of the total destructed exergy.


    In this study, greenhouse gas emission and exergy assessments of an integrated organic Rankine cycle (ORC) with a biomass combustor for combined cooling, heating, and power production as a trigeneration system are conducted. This trigeneration system consists of a biomass combustor, an ORC, a single-effect absorption chiller, and a heat exchanger. Four special cases are considered in this comprehensive study, namely, electrical power, cooling-cogeneration, heating-cogeneration, and trigeneration cases. Various exergetic and environmental output performance parameters, namely, exergy efficiency, exergy destruction rate, and greenhouse gas emissions, are examined under varying ORC evaporator pinch point temperature, pump inlet temperature, and turbine inlet pressure. This study shows that using trigeneration considerably increases both energy and exergy efficiencies and decreases the greenhouse gas emissions as compared to the electrical power case. This study reveals that the heating-cogeneration and trigeneration cases are less sensitive to the considered temperature and pressure variations as compared with the electrical power and cooling-cogeneration cases. In addition, the results show that when the trigeneration case is used, the exergy efficiency increases significantly to 27% as compared with the exergy efficiency of the electrical power case, which is around 11%. It is also found that the main two sources of exergy destruction are the biomass combustor and ORC evaporator. Moreover, this study shows that the emissions of CO2 in kg/MWh are significantly high for the electrical power case while for the trigeneration case, the emissions per MWh of trigeneration drop significantly to relatively low level. Specifically, the emissions drop to around one seventh per MWh produced when trigeneration is used as compared with only electrical power production case.

  93. Trigeneration: a comprehensive review based on prime movers
  94. JOURNAL PAPERSFA Al‐Sulaiman, F Hamdullahpur, I Dincer - International Journal of Energy Research, 2011


    In this paper, various aspects of trigeneration power plants including advantages, challenges and criteria for high efficiency operation are discussed. In trigeneration systems, prime movers are treated to be the heart of the plant and thus an appropriate selection is crucial for successful operation. A comparative analysis of potential prime movers, together with a comprehensive literature review used in trigeneration and, their selection criteria are presented. A case study of a trigeneration plant based on solid oxide fuel cells and an organic Rankine cycle is examined using thermodynamic analysis. This thermodynamic analysis includes performance assessment of the system through energy and exergy efficiencies. An environmental impact assessment is also conducted based on CO2 emissions as a measure. The present study reveals that compared to power cycle efficiency (considering net electrical efficiency), there is a minimum potential of 22% gain in efficiency when trigeneration is used. Also, it is shown that there is more than 200 kg MWh−1 reduction in CO2 emissions when trigeneration is used compared to the case where a power cycle is only used. Copyright © 2010 John Wiley & Sons, Ltd.


    In this study, the feasibility of using an organic Rankine cycle (ORC) in trigeneration plants is examined through thermodynamic modeling and thermoeconomic optimization. Three novel trigeneration systems are considered. Each one of these systems consists of an ORC, a heating-process heat exchanger, and a single-effect absorption chiller. The three systems are distinguished by the source of the heat input to the ORC. The systems considered are SOFC-trigeneration, biomass- trigeneration, and solar-trigeneration systems. For each system four cases are considered: electrical-power, cooling-cogeneration, heating-cogeneration, and trigeneration cases. Comprehensive thermodynamic analysis on each system is carried out. Furthermore, thermoeconomic optimization is conducted. The objective of the thermoeconomic optimization is to minimize the cost per exergy unit of the trigeneration product.

  95. Energy analysis of a trigeneration plant based on solid oxide fuel cell and organic Rankine cycle
  96. JOURNAL PAPERSFA Al-Sulaiman, I Dincer, F Hamdullahpur - International Journal of Hydrogen Energy, 2010


    In this study, energy analysis of a trigeneration plant based on solid oxide fuel cell (SOFC) and organic Rankine cycle (ORC) is conducted. The physical and thermodynamic elements of the plant include an SOFC, an ORC, a heat exchanger for the heating process and a single-effect absorption chiller for cooling. The results obtained from this study show that there is at least a 22% gain in efficiency using the trigeneration plant compared with the power cycle (SOFC and ORC). The study also shows that the maximum efficiency of the trigeneration plant is 74%, heating cogeneration is 71%, cooling cogeneration is 57% and net electricity is 46%. Furthermore, it is found that the highest net power output that can be provided by the trigeneration plant considered in this study is 540 kW and, the highest SOFC-AC power is 520 kW. The study reveals that the inlet pressure of the turbine has an insignificant effect on the efficiency. The study also examines the effect of both the SOFC current density and the SOFC inlet flow temperature on the cell voltage and voltage loss.

  97. Exergy analysis of an integrated solid oxide fuel cell and organic Rankine cycle for cooling, heating and power production
  98. JOURNAL PAPERSFA Al-Sulaiman, I Dincer, F Hamdullahpur - Journal of power sources, 2010


    The study examines a novel system that combined a solid oxide fuel cell (SOFC) and an organic Rankine cycle (ORC) for cooling, heating and power production (trigeneration) through exergy analysis. The system consists of an SOFC, an ORC, a heat exchanger and a single-effect absorption chiller. The system is modeled to produce a net electricity of around 500 kW. The study reveals that there is 3–25% gain on exergy efficiency when trigeneration is used compared with the power cycle only. Also, the study shows that as the current density of the SOFC increases, the exergy efficiencies of power cycle, cooling cogeneration, heating cogeneration and trigeneration decreases. In addition, it was shown that the effect of changing the turbine inlet pressure and ORC pump inlet temperature are insignificant on the exergy efficiencies of the power cycle, cooling cogeneration, heating cogeneration and trigeneration. Also, the study reveals that the significant sources of exergy destruction are the ORC evaporator, air heat exchanger at the SOFC inlet and heating process heat exchanger.

  • Granted US Patent US9500185 B2

    Al-Sulaiman, F. A

    System And Method Using Solar Thermal Energy for Power, Cogeneration and/or Poly-Generation Using Supercritical Brayton Cycles.

  • GrantedUS Patent US9643102 B2

    Al-Sulaiman, F. A. and Antar, M. A.

    Humidification-Dehumidification Desalination System.

  • FiledUS Patent US20170138649

    Ibrahim, N, ‎Al-Sulaiman, F. A.

    Gandhidasan, P; “Solar Absorption Heat Pump and Thermochemical Energy Storage,”.

  • FiledUS Patent 504601US

    ‎Al-Sulaiman, F. A.

    Augmentation of Solar Chimney for Power Production Using Fresnel Lens.

  • Filed US PTO

    ‎Al-Sulaiman, F. A, Antar, M, Ifras, MZ, Dini, S,

    Solar Humidifier And Dehumidifier Desalination Method And System For The Desalination Of Saline Water.

  • Filed US PTO

    ‎Al-Sulaiman, F. A.

    Augmentation of Solar Chimney for Power Production.

  • Filed US PTO

    ‎Abd-ur-Rehman, Hafiz M.; Shshzad, Haris; Al-Sulaiman, F. A.

    A Novel Design of Bubble Column Humidification-Dehumidification Water Desalination System.

  • Filed US PTO

    ‎Antar, M.; Lawal, DU; Khalifa, A; Zubair, S; Al-Sulaiman, F. A.

    Hybrid Humidification Dehumidification and Climatic Control System.

“Supercritical Carbon Dioxide Brayton Cycles Driven by Solar Thermal Power Tower System” in Recent Advances in Renewable Energy, Advanced Materials Research, Vol.(1116), 94-129.

Book ChapterAtif, M. and FA Al-Sulaiman , 2015

1.     Evaluation of solar thermal driven cooling system in office buildings in Saudi Arabia

Conference PapersMT Linjawi, Q Talal, FA Al-Sulaiman - E3S Web of Conferences, 2017

2.     Exergy Analysis of Solar Chimney for Saudi Arabian Weather Conditions

Conference PapersFM Hussain, FA Al-Sulaiman - ASME 2016 10th International Conference on Energy …, 2016

3.     Experimental Analysis of Solar Driven Multi-Stage Stepped Bubbler Humidifier for Humidification-Dehumidification (HDH) Water Desalination System

Conference PapersHM Abd-ur-Rehman, FA Al-Sulaiman, MA Antar - ASME 2016 10th International Conference on Energy …, 2016

4.     Thermodynamic Analysis of a Mini Hybrid Solar Driven Cooling-Desalination System

Conference PapersNI Ibrahim, FA Al-Sulaiman, S Rahman - ASME 2016 10th International Conference on Energy …, 2016

5.     Techno-economic evaluation of solar water heating applications at hospitals in Saudi Arabia

Conference PapersHA Almahmoud, FA Al-Sulaiman, H Abd-ur-rehman Solar World Congress 2015, Daegu, Korea

6.     Experimental Analysis of Solar Driven Bubble Column Humidifier for Humidification-Dehumidification (HDH) Water Desalination System

Conference PapersHM Abd-ur-Rehman, FA Al-Sulaiman, MA Antar

7.     Performance Analysis of Solar Tower Power Plants Driven Supercritical Carbon Dioxide Recompression Cycles for Six Different Locations in Saudi Arabia, Internatio...

Conference PapersFA Al-Sulaiman, M Atif, H Abd-Ur-Rahman

8.     Silicon Nanowire as an Effective Absorber for Solar Cell Application: Fabrication and Numerical Simulation,

Conference PapersMK Hossain, B Salhi, AW Mukhaimer, FA Al-Sulaiman

9.     Performance Analysis of Solar Chimney for Saudi Arabia Weather Conditions

Conference PapersFM Hussain, FA Al-Sulaiman

10.  Performance Assessment of Solar Tower Integrated with Regenerative Supercritical CO2 Brayton Cycle and MEETVC Desalination System, Concentrating Solar Po...

Conference PapersA Kouta, FA Al-Sulaiman, M Atif

11.  Performance Analysis of Recompression Supercritical CO2 Brayton Cycles Integrated with Solar Thermal Power Tower System under Different Thermal Energy Stor...

Conference PapersFA Al-Sulaiman, M Atif

12.  Energy Conservation Measures and Solar Energy Integration in Hot Climate Residential Buildings

Conference PapersHM Abd-ur-Rehman, FA Al-Sulaiman, IM Budaiwi, S Shakir

13.  Mathematical modeling of bubbler humidifier for humidification-dehumidification (HDH) water desalination system

Conference PapersHM Abd-ur-Rehman, FA Al-Sulaiman - Recent Advances in Mechanics and Mechanical …, 2015

14.  Time instant optimization of a heliostat field using a heuristic algorithm

Conference PapersM Atif, FA Al-Sulaiman - Eighth international conference on energy …, 2014

15.  Techno-economic evaluation of different types of solar collectors for water heating application in domestic sector of Saudi Arabia

Conference PapersHM Abd-ur-Rehman, FA Al-Sulaiman - Renewable Energy Congress (IREC), 2014 5th …, 2014

16.  Performance analysis of supercritical CO 2 Brayton cycles integrated with solar central receiver system

Conference PapersM Atif, FA Al-Sulaiman - Renewable Energy Congress (IREC), 2014 5th …, 2014

17.  Performance Assessment of a Solar Driven Combined Steam and Organic Rankine Cycles

Conference PapersFA Al-Sulaiman, AZ Sahin - World, 2012

18.  Exergy and Environmental Impact Assessments of an Integrated Organic Rankine Cycle with a Biomass Combustor for Combined Production of Cooling, Heating an...

Conference PapersFA Al-Sulaiman, F Hamdullahpur, I Dincer

19.  Energy and exergy assessments of a new trigeneration system based on organic rankine cycle and biomass combustor

Conference PapersFA Al-Sulaiman, F Hamdullahpur, I Dincer - Proceedings of ASME 2010 4th International …, 2010

20.  Efficiency and environmental impact assessments of a trigeneration plant using sofc and orc

Conference PapersFA Al-Sulaiman, F Hamdullahpur, I Dincer - Proceedings of the Global Conference on Global Warming, 2009

21.  Design of Small Centrifugal Compressors Performance Test Facility

Conference PapersFA Al-Sulaiman, AM Al-Qutub - ASME Turbo Expo 2004.

22.  Instrumentation Selection and Uncertainty Analysis for Performance Test of Small Centrifugal Compressors

Conference PapersAM Al-Qutub, FA Al-Sulaiman - ASME Turbo Expo 2004, ASME Paper GT2004-53828, 2004


  • ARE495: Fundamentals of Energy Efficiency
  • ME 203: Thermodynamics-I
  • ME 204: Thermodynamics-II
  • ME 315: Heat Transfer
  • ME 316: Thermo-fluids Laboratory
  • ME 411: Senior Project I (instructor)
  • ME 412: Senior Project II (instructor)
  • ME 414: Senior Project I for AME (instructor)
  • ME 416: Senior Project II for AME (instructor)
  • ME 413: Systems Dynamics & Control lab
  • ME 432: Internal Combustion Engines lab
  • ME 439: Solar Energy Conversion
  • ME 495: Directed Research/BSc Research
  • ME 539: Solar Energy Utilization (graduate course)
  • ME 606: Independent Research (graduate research MSc course)
  • ME 701: Directed Research I (graduate research PhD course)
  • ME 702: Directed Research II (graduate research PhD course)

Contact & Meet Me

I would be happy to talk to you if you need my assistance in your research or whether you need bussiness administration support.

Associate Professor
Director, Center of Research Excellence in Renewable Energy
Director, Center of Excellence in Energy Efficiency,
Research Institute,
King Fahd University of Petroleum & Minerals,
Dhahran, Saudi Arabia,