Showing papers by "Shafiqur Rehman published in 2018"

A hybrid renewable energy system as a potential energy source for water desalination using reverse osmosis: A review

Abstract: The water needs of the inhabitants of Saudi Arabia are met by desalination powered by electricity generated from fossil fuel. Excessive burning of fossil fuels results in faster depletion and causes an adverse impact on the local environment. Reverse osmosis (RO) desalination based on a hybrid renewable energy system (HRES) has emerged as a cleaner alternative. The primary objective of this review is to assess the current status of utilizing renewable energy for small and large-scale water desalination plants. An overview of the expansion of domestic and global desalination plant capacities is presented with the evaluation of Saudi Arabia’s renewable energy potential. Numerous studies on coupling various combinations of renewable energy sources to power desalination processes are reviewed. A comprehensive analysis of the trends and technical developments of PV-RO, Wind-RO, and hybrid PV-Wind-RO for a wide range of capacities over the past three decades is provided. Designing and modeling HRES-RO desalination systems using different combinations of renewable energy sources are thoroughly analyzed and the technical aspects of their performance are presented. The application of a range of optimization and sizing software tools available for conducting pre-feasibility analysis and the comparison of the available software tools for HRES-RO desalination are also presented. The study also demonstrated that the replacement of fossil fuel with renewable energy for desalination will significantly decrease greenhouse gas emissions. The review also highlights the effect of solar and wind profiles on the economics of desalination powered by renewables. The economic analysis indicates a significant decrease in the cost of water production by hybrid PV-wind-RO systems, implying good prospects for the technology in the near future. Finally, the study provides a flowchart depicting the steps involved in installing a hybrid PV-wind-RO system in KSA.

Horizontal Axis Wind Turbine Blade Design Methodologies for Efficiency Enhancement—A Review

Abstract: Among renewable sources of energy, wind is the most widely used resource due to its commercial acceptance, low cost and ease of operation and maintenance, relatively much less time for its realization from concept till operation, creation of new jobs, and least adverse effect on the environment. The fast technological development in the wind industry and availability of multi megawatt sized horizontal axis wind turbines has further led the promotion of wind power utilization globally. It is a well-known fact that the wind speed increases with height and hence the energy output. However, one cannot go above a certain height due to structural and other issues. Hence other attempts need to be made to increase the efficiency of the wind turbines, maintaining the hub heights to acceptable and controllable limits. The efficiency of the wind turbines or the energy output can be increased by reducing the cut-in-speed and/or the rated-speed by modifying and redesigning the blades. The problem is tackled by identifying the optimization parameters such as annual energy yield, power coefficient, energy cost, blade mass, and blade design constraints such as physical, geometric, and aerodynamic. The present paper provides an overview of the commonly used models, techniques, tools and experimental approaches applied to increase the efficiency of the wind turbines. In the present review work, particular emphasis is made on approaches used to design wind turbine blades both experimental and numerical, methodologies used to study the performance of wind turbines both experimentally and analytically, active and passive techniques used to enhance the power output from wind turbines, reduction in cut-in-speed for improved wind turbine performance, and lastly the research and development work related to new and efficient materials for the wind turbines.

Recent trends in wind speed across Saudi Arabia, 1978–2013: a break in the stilling

Abstract: We analyse recent trends and variability of observed near-surface wind speed from 19 stations across Saudi Arabia (SA) for 1978–2013. The raw wind speed data set was subject to a robust homogenization protocol, and the stations were then classified under three categories: (1) coast, (2) inland and (3) mountain stations. The results reveal a statistically significant (p< 0.05) reduction of wind speed of −0.058 m s−1 dec−1 at annual scale across SA, with decreases in winter (−0.100 m s−1 dec−1) and spring (−0.066 m s−1 dec−1) also detected, being non-significant in summer and autumn. The coast, inland and mountain series showed similar magnitude and significance of the declining trends across all SA series, except for summer when a decoupled variability and opposite trends of wind speed between the coast and inland series (significant declines: −0.101 m s−1 dec−1 and −0.065 m s−1 dec−1, respectively) and the high-elevation mountain series (significant increase: +0.041 m s−1 dec−1) were observed. Even though wind speed declines dominated across much of the country throughout the year, only a small number of stations showed statistically significant negative trends in summer and autumn. Most interestingly, a break in the stilling was observed in the last 12-year (2002–2013) period (+0.057 m s−1 dec−1; not significant) compared to the significant slowdown detected in the previous 24-year (1978–2001) period (−0.089 m s−1 dec−1). This break in the slowdown of winds, even followed by a non-significant recovery trend, occurred in all seasons (and months) except for some winter months. Atmospheric circulation plays a key role in explaining the variability of winds, with the North Atlantic Oscillation positively affecting the annual wind speed, the Southern Oscillation displaying a significant negative relationship with winds in winter, spring and autumn, and the Eastern Atlantic negatively modulating winds in summer.

Feasibility of a 100 MW Installed Capacity Wind Farm for Different Climatic Conditions

Abstract: Wind power is the world’s fastest-growing energy source. More power can be generated from wind energy through the use of new wind machine designs and techniques. The objective of the present work is to encourage people and governments to develop wind energy-based power plants to achieve sustainable energy infrastructures, especially in developing countries. In this paper, a feasibility study of a 100 MW grid-connected wind farm is conducted for five different cities of Saudi Arabia (KSA). The results indicate that the proposed power plant is feasible both technically and economically. All sites are found to be within the profitable range with Dhahran being the most feasible site among the others for the installation of the wind farm. A sensitivity analysis has also been carried out to find out the effects of different incentives on the payback period of the project.

Wind Speed Extrapolation Using Machine Learning Methods and LiDAR Measurements

Abstract: Accurate wind energy assessments require wind speed (WS) at the hub height. The cost of WS measurements grows enormously with height. This paper utilizes deep neural network (DNN) algorithm for the extrapolation of the WS to higher heights based on measured values at lower heights. LiDAR measurements at lower heights are used for training the system and at higher heights for performance analysis. These measurements are made at 10, $20,\ldots $ , and 120 m heights. First, the measured WS values at 10–40 m were used to extrapolate values up to 120 m. In the second scenario, the WS at 10–50 m were used to extrapolate values up to 120 m. This continued until the last scenario, in which the WS at 10–100 m were used to estimate values at 110 and 120 m. A relationship between heights of measurements and the accuracy of the WS estimation at hub height is presented. The WS extrapolated using the present approach is compared with the measured values and with local wind shear exponent (LWSE)-based extrapolated WS. Furthermore, to analyze the performance of the DNN relative to other machine learning methods, we compared its performance with that of classical feedforward artificial neural networks trained using a genetic algorithm to find the initial weights and the Levemberg–Marquardt (LM) method (GANN) for training. The mean absolute percent error between measured and extrapolated WS at height 120 m based on measurements between 10–50 m using DNN, GANN, and LWSE are 9.65%, 12.77%, and 9.79%, respectively.

Techno-economic study of a solar photovoltaic and diesel powered irrigation systems.

Abstract: aDepartment of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia, emails: g201520570@kfupm.edu.sa (M.Z. Al-Nabulsi), g201403960@kfupm.edu.sa (R. Miah) bCenter for Engineering Research, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia, email: srehman@kfupm.edu.sa cCenter of Research Excellence in Renewable Energy, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia, email: fahadas@kfupm.edu.sa

Renewable and Sustainable Air Conditioning

Abstract: The simultaneous control of air temperature and humidity are the main functions of an air conditioner in order to provide human thermal comfort conditions. The conventional vapor compression air conditioning system cools the air below its dew point temperature to remove the moisture from the air. In hot and humid regions, considerable amount of energy is used for moisture removal using these systems. Because of the high energy cost of conventional systems and poor control of latent load, need arises for some alternative cooling devices. In this chapter alternative and renewable based air conditioning systems are described to overcome the increasing use of primary energy by conventional air conditional systems. Desiccant cooling is found to be a suitable alternative to these cooling systems. The configurations of desiccant cooling systems to achieve better performance are described. Furthermore, a comparative analysis of desiccant cooling system operating on ventilation and recirculation cycle has been presented. The results showed the system operating under the ventilation cycle has a better coefficient of performance as compared to the recirculation cycle because of the less input/regeneration heat required. The desiccant cooling technology is both cost-effective and environmental friendly as no refrigerant is used in these systems.

Power transformer copper sulfide monitoring system

Abstract: An apparatus for measuring the rate of Cu 2 S formation in power transformers comprising a sealable transformer vessel and a sealable lid with at least four sealable ports, and an internal apparatus configuration involving a copper metal sheet, a power transformer, a temperature sensor, and a weighing device providing real-time feedback data, whereby these components are submerged in an effective amount of a reactive sulfur-containing transformer oil and sealed. An inert gas atmosphere is provided within the transformer vessel by a gas bubbler. The transformer oil is heated with a heating bath to a reactive temperature for Cu 2 S production. A method of measuring the rate of Cu 2 S formation whereby the apparatus is purged with an inert gas, heated to a reactive temperature, examined for Cu 2 S formation, the Cu 2 S produced is quantified and the rate of formation of Cu 2 S is calculated.