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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.

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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.

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The control of air conditioning latent and sensible load separately by using a desiccant dehumidifier operating in conjunction with evaporative cooler can reduce the air conditioning power requirement significantly. This system can also utilize the alternative resources of energy such as solar, waste heat, and natural gas effectively. In this article a mathematical model of desiccant evaporative cooling has been developed and the performance of the system is analyzed for its feasibility under the climatic conditions of Dhahran, Saudi Arabia. Different performance curves have been drawn to get optimum values of parameters under different operating conditions. Some new parameters such as sensible energy ratio have also been introduced for better prediction of system cooling capacity. The results showed that the proposed system is suitable and feasible solution to meet the high cooling demands for the conditions of Dhahran, Saudi Arabia with performance largely dependent on optimum selection of operating parameters.