MEGAJOULE preferably uses Mesoscale’s numerical model WRF – Weather Research and Forecasting. Developed by the U.S. National Center for Atmospheric Research (NCAR), WRF (an evolution of the original MM5) incorporates the latest scientific developments from the leading research centres, and is the result of decades of research.
The WRF model performs a dynamic downscaling of global data (such as more than 50 years of Reanalysis NCEP/NCAR data or 40 years of ERA40 from ECMWF) through a compressible, non-hydrostatic solver. It employs terrain-following hydrostatic-pressure vertical coordinates to capture topography-induced effects. WRF performs transient simulations using 2nd and 3rd order Runge-Kutta integration schemes, with reduced time steps to capture acoustic modes and gravitational waves.
The model has a set of parameterizations to describe the microphysics of atmosphere, surface interactions and parameterizations of cumulus, planetary boundary layer physics and atmospheric radiation. The physical models consider sub-grid-scale phenomena according to the spatial resolution desired. Over the past years, our Mesoscale Unit has calibrated the model to best suit our clients needs in terms of accuracy, delivery times and data analysis.
Mapping of wind resources - wind atlas
The wind atlas illustrates the annual average wind conditions in broad areas (regions, countries, etc). The simulations have a maximum resolution typically between 1 to 3 km.
We may either use publicly available data or assimilate local measurements (if available) to calibrate the model and/or validate results.
MEGAJOULE has produced several wind atlases to support developers in the initial site surveys and regional authorities for energy development planning purposes.
|Virtual series, micrositing and energy estimates|
The results of Mesoscale modeling together with Microscale simulations allow us to get the appropriate resolutions to obtain preliminary layout micrositing, energy estimates of the wind farm and resource mappings with lower resolutions (up to tens of meters).
It is also possible to extract annual wind time series from the Mesoscale modelling -Virtual Series- which can be used as an input in typical Microscale models, such as WAsP, with appropriate care regarding data resolution and accuracy issues.
In summary, the increasing quality of Mesoscale modeling has transformed it in a highly valuable tool, which can complement field data, or even replace it when it is not available. Mesoscale results can be invaluable in the preliminary stages of a wind farm project, both for preliminary wind resource assessments, as well as more advance stages such as defining preliminary layouts and estimating energy yields.
In the development and updating of its Mesoscale services, MEGAJOULE counts with the cooperation of the Physics Department of Aveiro University. MEGAJOULE has recently upgraded its computational resources with a 32-node cluster, meaning our clients can have even more accurate results in shorter time frames.