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Measure-Correlate-Predict
(MCP) Method
MCP is a statistical technique
used for predicting the long term wind resource at a proposed wind
farm site by relating measurements from a short-term measurement
campaign
to the long term measurements at meteorological site. Wind speed and
direction
data are recorded simultaneously at both the sites over a
recommended
minimum period of one year. The data has to be filtered to
improve
correlation quality. The concurrent data from proposed wind farm site
and meteorological
sites is binned according to the reference wind direction. For each
direction
bin, a straight line is fitted to the data by least square technique to
relate
the wind speeds of proposed wind farm site and meteorological sites.
The
coefficients slope, m and intercept, c are determined through linear
regression. The long term reference data (recommended to be 10 years
data at
least) are binned according to wind direction and for each direction
bin the
corresponding coefficient are used to adjust the wind speeds
accordingly
producing predicted wind speed distribution for each sector. For
complete
reference of MCP technique, refer Derrik
1992 in literature review section.
Linear
Regression Analysis
Two variables are related linearly if the
change
in their value is uniform. Linear regression is used to analyze the
relationship between them. It finds the slope and intercept for a
straight line that best fits the data.
Correlation
Parameters
slope m: it
represents the change in velocity of target site with respect to the
reference site
intercept
c:
it gives the velocity
of target site when the velocity of reference site is zero
Variation
in Correlation
Parameters
The main criterion
for selection of a year to carry out linear regression is that the Pearson
Correlation coefficient should be more than 0.7. Once we calculate the
correlation
parameters for one year, we do it for various years. We are capturing
the variation in correlation parameters for Lynemouth (pseudo wind farm
site) and Dumfries (meterological site) for 5 concurrant years.
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