bReeze-package: Functions for Wind Resource Assessment
In bReeze: Functions for Wind Resource Assessment

Description Details Author(s) References Examples

A collection of functions to analyse, visualize and interpret wind data and to calculate the potential energy production of wind turbines.

Wind power is a global source of energy which attracts a large share of investments in renewables. Project sites with high wind potential do not only minimise the financial risk but increase the efficiency in carbon footprint reduction. Hence a thorough productivity analysis of a wind project is essential, regarding both economic and environmental aspects. The evaluation of the potential of a site requires a wind resource assessment, which is best based on data gained by a local measurement campaign. A methodology of processing the measured data has been established, resulting in a better understanding of the wind conditions of a site and therefore a more reliable estimation of energy production.

bReeze is a collection of widely used methods to analyse, visualise and interpret wind data. Wind resource analyses can subsequently be combined with characteristics of wind turbines to estimate the potential energy production on the investigated site.

Usually the data to be analysed are collected by meteorological masts (met masts) and averaged over ten minutes, but other time intervals are also processable.

bReeze suggests three packages, written by other developers: RColorBrewer (by Erich Neuwirth) provides nice colours for the graphics, XML (by Duncan Temple Lang) provides xml parsing for power curve import and RgoogleMaps (by Markus Loecher) provides simple site maps.

Try the examples below to check if bReeze has been correctly installed. Any question and feedback is welcome via email to <christian.graul@gmail.com> or on GitHub.

Christian Graul and Carsten Poppinga

Maintainer: Christian Graul <christian.graul@gmail.com>

The following handbook gives a detailed thematic overview and is available online:

Brower, M., Marcus, M., Taylor, M., Bernadett, D., Filippelli, M., Beaucage, P., Hale, E., Elsholz, K., Doane, J., Eberhard, M., Tensen, J., Ryan, D. (2010) Wind Resource Assessment Handbook. http://www.renewablenrgsystems.com/TechSupport/~/media/Files/PDFs/wind_resource_handbook.ashx

Further references are given under the specific functions of the package.

## Not run: 
# load example data
data("winddata", package="bReeze")

# create two datasets
set40 <- set(height=40, v.avg=winddata[,2], v.std=winddata[,5],
  dir.avg=winddata[,14])
set30 <- set(height=30, v.avg=winddata[,6], v.std=winddata[,9],
  dir.avg=winddata[,16])

# format time stamp
ts <- timestamp(timestamp=winddata[,1])

# create met mast object
metmast <- mast(timestamp=ts, set40=set40, set30=set30)

# plot time series of met mast signals
plot(metmast)

# calculate frequency and mean wind speed per wind direction sector
freq <- frequency(mast=metmast, v.set=1)

# plot frequency
plot(freq)

# calculate availability of pairs of wind speed and direction
availability(mast=metmast)

# calculate monthly means of wind speed
month.stats(mast=metmast)

# calculate turbulence intensity
turbulence(mast=metmast, turb.set=1)

# calculate weibull parameters
wb <- weibull(mast=metmast, v.set=1)

# calculate total wind energy content
energy(wb=wb)

# calculate wind profile
pf <- windprofile(mast=metmast, v.set=c(1,2), dir.set=1)

# import power curve
pc <- pc("Enercon_E126_7.5MW.pow")

# calculate annual energy production
aep <- aep(profile=pf, pc=pc, hub.h=135)

# plot AEP
plot(aep)

## End(Not run)

 
This is bReeze 0.4-3
 
Type changes("bReeze") to see changes/bug fixes, help(bReeze) for documentation
or citation("bReeze") for how to cite bReeze.
 

Attaching package: 'bReeze'

The following objects are masked from 'package:stats':

    frequency, ts

The following object is masked from 'package:utils':

    timestamp

Pattern found: %d.%m.%Y %H:%M

	Frequency

    wind speed  total    0-5   5-10 10-15 15-20   >20
         [m/s]    [%]    [%]    [%]   [%]   [%]   [%]
N        5.611 27.069 11.281  13.93 1.795 0.063      
NNE       3.89  6.047  4.063  1.984                  
ENE      3.665  3.089  2.274  0.804 0.011            
E        2.707  1.737  1.557  0.178 0.003            
ESE      2.838  1.885  1.524  0.361                  
SSE      2.538  4.586  4.022  0.564                  
S        3.052 11.639  9.918  1.579 0.142            
SSW      5.042 15.155  8.854  4.556 1.426 0.312 0.008
WSW       5.74 15.623  7.046  6.698 1.519 0.361      
W        3.406  6.258  4.684  1.491 0.082            
WNW       1.62   2.46  2.378  0.082                  
NNW      2.673  4.452  3.738  0.703 0.011            
all      4.472    100 61.339 32.929 4.988 0.736 0.008

call: frequency(mast=metmast, v.set=1, dir.set=1, num.sectors=12, bins=c(0, 5, 10, 15, 20), subset=NA, digits=3, print=TRUE)


	Availability for pairs of wind speed and direction

      availability effective period total period
               [%]              [d]          [d]
set40         93.8            253.8        270.5
set30         93.8            253.8        270.5

number of daily samples:
set40 
            %   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16
2009-05  82.3   0   0   0   0   0  76 144 144 144 144 144 144 144 144 144 144
2009-06 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-07 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-08 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-09 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-10  99.8 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-11  44.7 143 144 144 144 144 144 144 144 144 144 144 144 144  60   0   0
2009-12  99.8 137 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2010-01 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
         17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
2009-05 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-06 144 144 144 144 144 144 144 144 144 144 144 144 144 144    
2009-07 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-08 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-09 144 144 144 144 144 144 144 144 144 144 144 144 144 144    
2009-10 144 144 144 144 144 144 144 144 144 144 144 144 144 144 138
2009-11   0   0   0   0   0   0   0   0   0   0   0   0   0   0    
2009-12 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2010-01 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144

set30 
            %   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16
2009-05  82.3   0   0   0   0   0  76 144 144 144 144 144 144 144 144 144 144
2009-06 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-07 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-08 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-09 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-10  99.8 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-11  44.7 143 144 144 144 144 144 144 144 144 144 144 144 144  60   0   0
2009-12  99.8 137 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2010-01 100.0 143 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
         17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
2009-05 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-06 144 144 144 144 144 144 144 144 144 144 144 144 144 144    
2009-07 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-08 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2009-09 144 144 144 144 144 144 144 144 144 144 144 144 144 144    
2009-10 144 144 144 144 144 144 144 144 144 144 144 144 144 144 138
2009-11   0   0   0   0   0   0   0   0   0   0   0   0   0   0    
2009-12 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144
2010-01 144 144 144 144 144 144 144 144 144 144 144 144 144 144 144

call: availability(mast=metmast, v.set="all", dir.set="all", subset=NA, digits=1, print=TRUE)


	Monthly statistics

set40 
                2009  2010  mean mean of months
JAN                  3.431 3.431          3.431
FEB                                            
MAR                                            
APR                                            
MAY            4.911       4.911          4.911
JUN            4.035       4.035          4.035
JUL            3.776       3.776          3.776
AUG            3.875       3.875          3.875
SEP            4.939       4.939          4.939
OCT            4.597       4.597          4.597
NOV            5.764       5.764          5.764
DEC            5.734       5.734          5.734
mean           4.617 3.431 4.472               
mean of months 4.704 3.431                4.563

set30 
                2009  2010  mean mean of months
JAN                  3.315 3.315          3.315
FEB                                            
MAR                                            
APR                                            
MAY            4.711       4.711          4.711
JUN            3.859       3.859          3.859
JUL            3.566       3.566          3.566
AUG            3.703       3.703          3.703
SEP            4.676       4.676          4.676
OCT            4.311       4.311          4.311
NOV            5.571       5.571          5.571
DEC            5.472       5.472          5.472
mean           4.394 3.315 4.262               
mean of months 4.483 3.315                4.354

call: month.stats(mast=metmast, set="all", signal="v.avg", fun="mean", subset=NA, digits=3, print=TRUE)


	Turbulence intensity

    total   0-5  5-10 10-15 15-20   >20
N   0.196 0.252 0.157 0.144 0.145 0.000
NNE 0.242 0.290 0.142 0.000 0.000 0.000
ENE 0.264 0.308 0.140 0.176 0.000 0.000
E   0.296 0.312 0.158 0.000 0.000 0.000
ESE 0.266 0.297 0.135 0.000 0.000 0.000
SSE 0.257 0.275 0.125 0.000 0.000 0.000
S   0.261 0.282 0.145 0.134 0.000 0.000
SSW 0.249 0.320 0.161 0.127 0.113 0.117
WSW 0.232 0.334 0.154 0.129 0.120 0.000
W   0.297 0.345 0.156 0.121 0.000 0.000
WNW 0.393 0.400 0.178 0.000 0.000 0.000
NNW 0.305 0.327 0.189 0.194 0.000 0.000
all 0.244 0.302 0.155 0.134 0.119 0.117

call: turbulence(mast=metmast, turb.set=1, dir.set=1, num.sectors=12, bins=c(0, 5, 10, 15, 20), subset=NA, digits=3, print=TRUE)

6 none-positives found and excluded from calculation

	Weibull parameters

        A     k wind speed frequency
    [m/s]   [-]      [m/s]       [%]
N   6.335 2.096      5.611    27.069
NNE 4.391 2.068       3.89     6.047
ENE 4.119 1.778      3.665     3.089
E   3.004 1.527      2.707     1.737
ESE 3.102 1.367      2.838     1.885
SSE 2.772 1.362      2.538     4.586
S    3.36 1.433      3.052    11.639
SSW 5.504 1.358      5.042    15.155
WSW 6.407 1.612       5.74    15.623
W   3.766 1.476      3.406     6.258
WNW 1.713 1.177       1.62      2.46
NNW 2.868 1.246      2.673     4.452
all 4.932 1.449      4.472       100

call: weibull(mast=metmast, v.set=1, dir.set=1, num.sectors=12, subset=NA, digits=3, print=TRUE)


	Wind energy content

    total 0-5 5-10 10-15 15-20
N     468 195  241    31     1
NNE    35  24   12            
ENE    18  13    5            
E       5   4    1            
ESE     7   6    1            
SSE    13  11    2            
S      52  44    7     1      
SSW   325 190   98    31     7
WSW   387 175  166    38     9
W      37  28    9            
WNW     2   2                 
NNW    17  14    3            
all  1366 706  545   101    17
	(all values in kWh/m^2/a)

call: energy(wb=wb, rho=1.225, bins=c(0, 5, 10, 15, 20), digits=0, print=TRUE)


	Wind profile

    alpha wind speed
      [-]      [m/s]
N   0.249      5.614
NNE 0.243       3.89
ENE 0.175      3.665
E   0.214      2.707
ESE 0.194      2.838
SSE 0.168      2.538
S   0.163      3.052
SSW 0.159      5.042
WSW  0.16       5.74
W   0.228      3.406
WNW 0.331       1.62
NNW 0.237      2.673
all 0.204      4.473

reference height: 40 m 

call: windprofile(mast=metmast, v.set=c(1, 2), dir.set=1, num.sectors=12, method="hellman", alpha=NULL, subset=NA, digits=3, print=TRUE)


	Annual energy production

      wind speed operation   total     0-5    5-10   10-15   15-20     >20
           [m/s]     [h/a] [MWh/a] [MWh/a] [MWh/a] [MWh/a] [MWh/a] [MWh/a]
N          7.191      2371    4824      91    1840    2423     447      23
NNE        4.986       530     422      32     290      97       2        
ENE        4.697       271     206      16     128      59       3        
E          3.469       152      56       8      37      10                
ESE        3.637       165      81       8      47      23       2        
SSE        3.253       402     144      20      89      33       2        
S          3.911      1020     580      53     333     175      18       1
SSW        6.462      1328    2376      52     677    1042     450     154
WSW        7.357      1369    3020      51     836    1408     575     150
W          4.366       548     406      28     217     141      18       1
WNW        2.076       215      25       7      15       3                
NNW        3.425       390     183      18      99      57       8       1
total      5.732      8760   12323     384    4608    5471    1525     330

capacity factor: 0.188 

call: aep(profile=pf, pc=pc, hub.h=135, rho=1.225, avail=1, bins=c(0, 5, 10, 15, 20), sectoral=FALSE, digits=c(3, 0, 0, 3), print=TRUE)