Vol 22, No. 9;Sep 2015 146 office@multidisciplinarywulfenia.org Performance Evaluation of Vertical Axis Wind Turbine for Small off grid loads in North-Eastern Region of Saudi Arabia Shafiqur Rehman Center for Engineering Research, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran-31261, Saudi Arabia Email: srehman@kfupm.edu.sa Md. Mahbub Alam (Corresponding author) 1 Institute for Turbulence–Noise–Vibration Interaction and Control, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China Email: alamm28@yahoo.com Luai M. Alhems Center for Engineering Research, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran-31261, Saudi Arabia Email: luaimalh@kfupm.edu.sa Aref Lashin King Saud University, College of Engineering - Petroleum and Natural Gas Engineering Department, Saudi Arabia Benha University, Faculty of Science - Geology Department, P.O. Box 13518, Benha - Egypt. Email: aref70@hotmail.com Nasser Alarefe King Saud University, College of Science -Geology and Geophysics Department, Riyadh 11451 - Saudi Arabia Abstract Small vertical axis wind turbines of 1-10kW rated powers were used to find suitable and efficient ones for power generation in the north-eastern region of Saudi Arabia. Additionally, the effect of hub height on energy output and the plant capacity factor was investigated to recommend an appropriate hub height. To achieve the set objectives, hourly mean wind speed data measured at 20, 30, and 40 meter and wind direction at 30 and 40 meter during September 13, 2005 to May 09, 2010 was utilized. The annual mean wind speed values were 5.73, 5.34, and 4.75 m/s at 40, 30, and 20 m with NNW as the prevailing wind direction. An increase of about 20.7% was estimated in wind speed at 40m compared to that at 20m. Wind turbines Aeolos-V, Aeolos-V2 and UGE of 3, 5, and 10kW with annual energy yield and plant capacity factor of 4.483MWh and 17.1%, 8.004MWh and 18.3%, and 10.181MWh and 11.6% were efficient for the location. Highest increase in annual energy yield was obtained for a change of 5 m from 10 to 15 m in hub height while the next best yield was obtained for a hub height change from 15 to 20 m. Keywords: Small vertical axis wind turbine; wind speed; hub height; turbulence intensity; wind power density, annual energy yield, plant capacity factor 1. INTRODUCTION Globally increasing population, fast technological development, luxurious, and materialistic life styles have resulted in un-proportionate increase in power requirements. Hence new and renewable sources of energy in addition to regular means of power generation are being explored to meet the increasing demands. Exploitation and utilization of clean energy sources reduces the dependence on fossil fuels