Development of a Wind Atlas for South Africa

The first validated Wind Atlas for South Africa (WASA) was a joint undertaking between South African and Danish scientists to provide stakeholders with the best possible information about the wind climate over the western parts of South Africa. Two subsequent phases of the project have facilitated the expansion of the wind atlas to cover the entire country and this paper reports on results of the final phase.

Activities within WASA include (1) an observation campaign in which 19 observation masts (62-metre masts with anemometers at 5 levels) have been erected at selected sites during each phase with up to 10 years of data at the earliest masts; (2) mesoscale modelling using the WRF model that produced the first ever validated numerical wind atlas during WASA phase 1; (3) microscale modelling using the Wind Atlas Analysis and Application Program (WAsP) to develop the high resolution wind atlas (grid spacing of 250 m) over the whole of South Africa; (4) an extreme wind climate assessment that has identified extreme wind-producing synoptic systems, their seasonal and spatial characteristics as well as regions in South Africa particularly prone to extreme wind conditions; and (5) dissemination of all data developed during the project to stakeholders and the general public at no cost including mast observation data, the mesoscale modelling data including a time series for each grid point in the 3.3 km domain, and the wind atlas itself through a web-based interface .

This paper presents a brief overview of the WASA project and focus on the mesoscale modelling results from WASA phase 3. We present the sensitivity testing that determined the production run setup of the WRF model, evaluation of the production run against the observations, the WASA time series data and discuss the results in the context of renewable energy potential in South African Integrated Resource Plan.