Wind power generation variations and aggregation
Cong Wu, Xiaoping Zhang, M.J.H. Sterling
Abstract
Wind power driven by climate and weather is characterized by significant spatial and temporal variability. It is evidenced that the variability of wind power will not only cause instability of power grids but also increase the balancing costs of electricity markets. Existing studies have shown that such variability can be reduced through aggregation of a geographic spread of production sites but there is a lack of comprehensive analysis for different levels/scales of aggregation, especially from a global perspective. The aim of this paper is to provide a fundamental understanding of the relationship between wind power variations and aggregations from a systematic viewpoint based on highly detailed wind power data, enabling the aggregation benefits to be quantified from a state scale up to a global scale. Firstly wind power variations are analyzed comprehensively at 6 different levels by converting global seven year hourly meteorological re-analysis data with a high spatial resolution of 0.25° × 0.25° (∼ 28 km × 28 km) into wind power series. Then in the proposed assessment framework, a coefficient of variation of wind power, and a standard deviation of wind power ramping rate are used to quantify wind power variations and wind power ramping rate variations to show the characteristics and benefits of wind power aggregation at the 6 different levels. A system planning example is used to show the correlation between CV reduction of wind power and investment reduction, and hence the benefits in terms of significant investment reduction via aggregation. Additionally, a wind power duration curve is further used to characterize the availability of wind power aggregated at different levels. Finally, the results would provide insights to shape an international approach to the deployment of wind power, especially under the framework of Net-Zero.