Page 135 - Fluid Power Engineering

112 Chapter Seven

Preliminary
Assessment

Multiple Sources Acceptable? Multiple Locs
of Wind Data Multiple Sensors
YES
Onsite
Measurement
Multiple
Multiple Site Spatial Reference
Statistics Extrapolation Datasets
Long-term
Hindcast
Annual Energy
Production
Multiple Uncertainty Multiple
Turbines Analysis Scenarios
Financial
Analysis

Acceptable?

STOP PROCEED

FIGURE 7-1 Overall process of Wind Resource Assessment (WRA) and
financial analysis. The gray boxes are steps in WRA. Inputs to each step are
indicated.

alsoinvolvesapreliminaryfinancialassessmenttodetermineifawind
project is viable. If the site is acceptable, then an onsite wind measure-
ment campaign is conducted. After wind data has been collected for
sufficient period, typically one year or more, then a process of detailed
WRA begins. It begins with spatial extrapolation, in which measured
data at multiple locations within the project area are used to estimate
wind speeds over the entire project area. This is extrapolation along
the spatial dimension.
The next step in the detailed WRA is to extrapolate along the tem-
poral dimension. A process called measure-correlate-predict (MCP)
is used with multiple reference datasets as input. Reference datasets
are long-term wind data from a variety of sources like reanalysis
data from National Center for Atmospheric Research (NCAR), air-
ports, and others. MCP extrapolates onsite measured data and gen-
erates a long-term dataset that covers the time period covered by
the reference dataset. Next, annual energy production (AEP) is com-
puted with several power production curves from different turbines.
The last step is to compute uncertainty of AEP, which consolidates the
uncertainty in each factor that influences AEP.