Balancing wind and solar power variability through spatial deployment informed by weather regimes: A review and roadmap ahead

Due to climate change and the dangers associated with it, there is a global trend away from fossil fuels and towards renewable energy sources, such as wind and solar power in electricity generation. South Africa (SA) is following this trend, with wind and PV expected to provide 33% of energy by 2030. The energy provided by wind and solar is however variable which poses several challenges to electricity networks. At short to medium term timescales of hours to days, wind power variability is typically resultant from large-scale and long-lasting weather regimes (WRs). This review paper aims to provide a detailed overview of the relationship between wind and solar power variability and WRs as reported in the literature, particularly how the relationship may be used to inform spatial deployment of variable renewable energy (VRE) generators in SA, to reduce variability. The study hypothesis is that spatial deployment of wind and solar power installations, informed by atmospheric WRs, may be used to mitigate wind and solar power variability. In support of this hypothesis, this paper provides a broad overview of previous studies on the relationship between VRE and WRs, emphasizing the most important questions under investigation and summarizing certain key facts. Secondly the different methods proposed for minimizing the variability in renewable energy resources are reviewed. It is established that limited research has yet been done on the relationship between VRE variability and WRs specific to SA. Finally, the paper provides a roadmap for future studies. Understanding the relationship between wind and solar power variability and WRs, and finding a method for reducing variability would be beneficial to network planners, VRE plant developers, and network operators.