the techniques used for wind resource assessment?
There are three basic steps to identify and characterize the wind resource in a given region. In general, they are prospecting, validation and optimization. In prospecting, the identification of potential windy sites within a fairly large region, in the range of several square kilometers areas would be considered. Generally this is carried out
by meteorologists who depend on various sources of information such as topographical maps (in India, Survey of India map), climatological data from meteorological stations (e.g. India Meteorological Department), and satellite imageries, etc. A site visit also will be conducted at this stage and a representative location for wind measurement would be identified.
Validation process involves a more detailed level of investigation like wind measurements and data analysis. The most imperative and final step is micro survey and micrositing. The main objective of this step is to quantify the small scale variability of the wind resource over the region of interest. In micro survey, a small region in and around a wind monitoring station ( generally 10 km radius) will be taken as a reference station for horizontal and vertical assessment. Finally, micrositing is carried out to position the wind turbines on a given area of land to maximize the overall energy output of the wind farm. In complex terrain, micrositing may involve two or more measurements, as a single site wind data cannot give good results. There are several industry standard Software in the market for resource modeling over a small region (micro survey) and later for micrositing. Wind Atlas Analysis Application Programme (WAsP), Resoft Wind Farm, Wind PRO and GH Wind Farmer are some of the models available in the market. As the mathematical equations used in these models are linearised, there are some limitations in using these models in all atmospheric and topographic conditions. Even if these models have some limitations, they can give good results if 'handled' circumspectly.