Chapter:
What are the techniques used for wind resource assessment?
What are
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.
Related Topics