Page 55 - Energize January 2022

TECHNICAL

Regional climatology is generally derived from historic large-scale
wind data sources. The generalised wind climatology process is
derived from mesa or large-scale weather data, obtained from
weather monitoring sources and validated by ground-based
stations.
The extrapolation process requires a detailed knowledge of the
terrain surrounding the site and the effect of topological features
on wind speed. Begun in 2010, the project consisted of three
phases, WASA1, 2 and 3. WASA 3 was concluded in October 2021.

There are two processes involved which run concurrently:
modelling and verification

MESOscale modelling
Mesoscale modelling involves construction of a model based on
macroscale (global) wind patterns, using knowledge of wide area
terrain features to scale down to a MESOscale (regional) wind
pattern (using 100 km blocks), in this case the Weather Research
and Forecasting (WRF) model. The mesoscale model uses a
variety of global, geophysical and meteorological databases such
as the Reanalysis database. This database is a gridded historical
weather data set produced by many weather bureaus or research
centres across the globe. WRF is a numerical weather prediction
(NWP) system designed to serve both atmospheric research and
operational forecasting needs which allows for the production of
simulations reflecting either real data (observations, analyses) or
idealized atmospheric conditions.
Figure 3 shows a Mesoscale WRF wind map showing long term
averaged wind speeds at a height of 100 m AGL.
Figure 4: WASA high resolution wind resource map: Mean wind speed
[ms ] @ 100 m a.g.l., December 2020 (3,3 km WRF + 250 m WAsP
-1
modelling) 3

Verification
In parallel with this program there is a physical wind speed
measurement and recording program, using specifically designed
masts installed at specially chosen sites around the country. Data
from the masts is used to validate the calculated values (Figure 5).

Figure 3: Mesoscale wind map 3

Microscale modelling
MESOscale data is used as input to the WAsP computer program
which produces microscale wind data using detailed data on
roughness, orography and obstacles. The WAsP program typically
2
produces wind pattern data in areas of 250 m . WAsP is a software
package used to evaluate the wind potential at specific sites,
developed by the Danish Technical University, and capable of
estimating site wind potential based on higher level input from
either observations or local climate models (WRF). WAsP was used
in developing the WASA. Figure 5: Location of the wind monitoring masts 3

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