Abstract
The objective of this work package has been to develop a “Large-Scale High Resolution Wind Resource map for all of South Africa, based on a new 3-km Validated Numerical Wind Atlas”.
This has been taken to mean that the results are generated as follows:
1. Maps are research-based, taking into account the latest knowledge; if at all possible
2. Maps are based on the full wind atlas methodology used in WASA Phases 1 and 2
3. Maps are high resolution, 250 m, and given for three heights, 50, 100 and 150 m
4. Maps cover all of South African land mass, and are divided into provinces
5. Databases of main results for all of South Africa are GIS compatible
6. Databases of additional results are comprehensive, i.e. contain Weibull A- and kparameters and frequencies of occurrence for 12 sectors and three heights at all nodes.
7. Database of 3-km wind atlas files cover all of South Africa
The work reported here, and the results obtained, are necessarily of an interim nature. This is a feature and hallmark of the WASA project and approach; that the methods used are developed constantly and that the result therefore may improve over time as updated models, procedures and data become available. Improved maps and data will therefore be presented in the WASA projects Phase 3.
Improvements to the present mapping compared to the 2014- and 2017-editions are mainly related to an even and systematic national coverage, new mesoscale modelling results at 3-km resolution, an updated downscaling procedure and improved microscale modelling. The microscale modelling is now done using WAsP 12 versions of the microscale models.
The topographical inputs to the WAsP microscale modelling consist of SRTM elevation data (as used in previous modelling), and a new land cover data set referred to as ESACCI 2015. This data set was used for both the mesoscale and microscale modelling; initially we have used a translation table between land cover and roughness length that is also used for the Global Wind Atlas.
Investigations of land cover and roughness data sets will continue in Phase 3, where more land cover data sets and translation tables will be analysed and compared. Likewise, the variation of atmospheric stability over South Africa will be investigated, in order to obtain the best possible detailed wind resource maps at the end of WASA Phase 3. It is therefore anticipated that future versions of the wind atlas data sets and detailed wind resource maps will improve e.g. because of the improved land cover and stability information.
The Large-Scale High-Resolution Wind Resource map for all of South Africa, based on a new 3- km Validated Numerical Wind Atlas is validated by comparing modelled results to the observed wind climates at the 10 WASA 1 masts and the 5 WASA 2 masts.
The present report, together with the accompanying maps and data sets in GIS compatible formats, constitute the final outputs of WP34.01c Report with ArcGIS ASC files, and are updates and extensions to previous components WP24.02 Microscale resource maps for WASA 2 domain (part of All SA) and WP24.03 Resource maps for WASA1 domain updated.
This has been taken to mean that the results are generated as follows:
1. Maps are research-based, taking into account the latest knowledge; if at all possible
2. Maps are based on the full wind atlas methodology used in WASA Phases 1 and 2
3. Maps are high resolution, 250 m, and given for three heights, 50, 100 and 150 m
4. Maps cover all of South African land mass, and are divided into provinces
5. Databases of main results for all of South Africa are GIS compatible
6. Databases of additional results are comprehensive, i.e. contain Weibull A- and kparameters and frequencies of occurrence for 12 sectors and three heights at all nodes.
7. Database of 3-km wind atlas files cover all of South Africa
The work reported here, and the results obtained, are necessarily of an interim nature. This is a feature and hallmark of the WASA project and approach; that the methods used are developed constantly and that the result therefore may improve over time as updated models, procedures and data become available. Improved maps and data will therefore be presented in the WASA projects Phase 3.
Improvements to the present mapping compared to the 2014- and 2017-editions are mainly related to an even and systematic national coverage, new mesoscale modelling results at 3-km resolution, an updated downscaling procedure and improved microscale modelling. The microscale modelling is now done using WAsP 12 versions of the microscale models.
The topographical inputs to the WAsP microscale modelling consist of SRTM elevation data (as used in previous modelling), and a new land cover data set referred to as ESACCI 2015. This data set was used for both the mesoscale and microscale modelling; initially we have used a translation table between land cover and roughness length that is also used for the Global Wind Atlas.
Investigations of land cover and roughness data sets will continue in Phase 3, where more land cover data sets and translation tables will be analysed and compared. Likewise, the variation of atmospheric stability over South Africa will be investigated, in order to obtain the best possible detailed wind resource maps at the end of WASA Phase 3. It is therefore anticipated that future versions of the wind atlas data sets and detailed wind resource maps will improve e.g. because of the improved land cover and stability information.
The Large-Scale High-Resolution Wind Resource map for all of South Africa, based on a new 3- km Validated Numerical Wind Atlas is validated by comparing modelled results to the observed wind climates at the 10 WASA 1 masts and the 5 WASA 2 masts.
The present report, together with the accompanying maps and data sets in GIS compatible formats, constitute the final outputs of WP34.01c Report with ArcGIS ASC files, and are updates and extensions to previous components WP24.02 Microscale resource maps for WASA 2 domain (part of All SA) and WP24.03 Resource maps for WASA1 domain updated.
| Original language | English |
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| Publisher | DTU Wind Energy |
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| Volume | 0179 |
| Number of pages | 42 |
| Publication status | Published - 2018 |
| Series | DTU Wind Energy E |
|---|---|
| Volume | 0179 |