Download WindRose User's Guide

WINDROSE : Wind Data Analysis software
the wind speed at the specific sector falls in the 4 preset ranges7 :
[2m/s-5m/s), [5-10m/s), [10-15m/s), [>15m/s).
This sheet is composed by the total and the monthly wind roses
(distribution chart in polar co-ordinates). They present the wind speed
distribution (%) per direction, in the time and energy domain.
WindRose
May
% energy
N
NNW
NW
WNW
W
7
6
5
4
3
2
1
0
% time
N
NNE
NNW
NE
30
NW
NE
20
ENE
15
WNW
ENE
10
5
E
0
W
WSW
NNE
25
E
ESE
WSW
SW
ESE
SE
SSW
SW
SSE
SE
SSW
S
SSE
S
Samples of a site’s wind roses (total and monthly)
Note that, for maximum precision, the polar plots are divided in 64
sectors, each 5.625° (=360°/64) wide. Each point of the drawn line,
represents the mean value of all the data within this sector, i.e. the
value of the distribution at 0° is the mean value of all the data found
within the sector [-2.8125, +2.8125).
It is reminded here that, in order to calculate both time and energy
distributions per direction sector, only data with wind speeds greater
than the calm limit (set in the Input worksheet) are taken into account.
If the user wants to change this and take into account the total data, he
has to set the calm limit to 0m/s and re-run the program.
Finally, note that the energy refers to the energy of the wind, not the
estimated electrical energy of the wind turbine. Although, in most of
the cases the two distributions are identical, differences might exist in
case of very high wind speeds (greater than the cut-out wind speed),
where the wind turbine is supposed to shut down.
7 The low limit is actually the calm threshold value (as set in the Input sheet), below of
which the response of the wind direction measuring device is not reliable.
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