Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser A comprehensive review of wind resource assessment K.S.R. Murthy ⁎ , O.P. Rahi Department of Electrical Engineering Department, National Institute of Technology, Hamirpur (H.P) 177005, India ARTICLE INFO Keywords: Preliminary assessment Statistical approach Weibull distribution Wind atlas Wind resource assessment Wind speed Wind turbine technology ABSTRACT A minor deviation in wind speed causes large deviation in the output power of wind turbine because of cubic bond association between these two parameters. Therefore, a precise assessment of wind resource over any site is considered of paramount significance. The investigations associated with the wind resource assessment have been proved of immense help for installation of different wind energy technologies such as nano, micro, small, medium, and large scale for wind energy generation. In order to provide a detailed information regarding the research in wind resource assessment a comprehensive literature review encompassing the different techniques, methodologies involved in development of wind power projects, and uncertainties associated with wind resource assessment as well as the preliminary assessment methodologies have been presented in this work. The advanced computational models namely wind atlas analysis and program, WindPro, computational fluid dynamics, and geographical information system are most frequently used software tools for mapping, modelling and annual energy estimation for a single or multiple wind turbines by considering the local conditions such as topography, surrounding obstacles, orography, and surface roughness based on the on-site measurements for a particular site. In addition, the statistical methods for short and long term data analysis, vertical wind speed profile, numerical weather prediction models, optimization of existing wind resource, and scope of hybrid wind energy systems have been delineated in this paper. Furthermore, current review presents a complete approach with reference to all the facets of the present status of research in the area of wind resource assessment worldwide. 1. Introduction The energy sector assumes critical importance in view of ever increasing demand requiring huge investments. There has been a sturdy association between commercial activities and accessibility to the energy resources depending on the historical data. Electricity generation is a major driving force for the financial progress of developing economies like India, which has been viewing a phenom- enal industrial progress. The generation of electricity by fossil fuels has been one of the prominent activity in such fuel based economies throughout the world, however such type of electricity generation imposes an adverse threat to the environment due to pollution, in the form of greenhouse gases emissions in the environment, thereby causing problems like global warming, acid rains, and climate change [1]. In global context, electricity generation by renewable energy applications show that the major contribution is from hydro and wind resource whereas a small portion comes from reaming renewable sources like solar, biomass, geothermal, wastes, and tidal wave ocean energy. Renewable generation technologies have been considered pollution free energy sources and their optimum use curtail the impact on environment, causes minimum secondary wastes, and have proved sustainable [2]. In present scenario, 657 GW of renewable power is contributed by the various renewable energy sources (RES) such as wind power, solar power, bio power, geothermal power, and concen- trating solar thermal power and ocean power globally. Fig. 1 reveals that the total renewable power installed in top seven countries during from 2004 to 2014 [3]. All the RES except geothermal and tidal are the manifestation of ultimate energy of sun. The sun emits the 174,423,000,000,000 kWh amount of energy to the earth surface, also it can be expressed in terms of power i.e. about 1.74×10 17 W which is received by the earth's surface with a circular area of 1.27×10 14 m 2 and is about 1–2% of the energy received from the sun is transformed into wind energy and this meagre percentage is approximately 50–100 times higher than the energy obtained from the biomass, i.e. energy conversion from all the plants on this earth [4]. The wind is caused due to the natural flow of air across the sea or on the earth surface. The earth's rotation and temperature difference on account of uneven heating and cooling of its surface causes winds to blow. The heat received from the sun is absorbed by the land and water areas in varying amounts, as a result, http://dx.doi.org/10.1016/j.rser.2016.10.038 Received 9 May 2015; Received in revised form 22 July 2016; Accepted 25 October 2016 ⁎ Corresponding author. E-mail address: harikella96@gmail.com (K.S.R. Murthy). Renewable and Sustainable Energy Reviews 72 (2017) 1320–1342 Available online 03 November 2016 1364-0321/ © 2016 Elsevier Ltd. All rights reserved. MARK