Introduction to power system flexibility planning

With the growing share of renewable energy in power generation, the chasm between planning and operation caused by the absence of planning consideration for flexibility is greatly deepened and is identified as the root cause behind wind and solar power curtailment. What is in dire need, as far as flexibility planning is concerned, is the improvement of theoretical foundation, mathematical model, and optimization approaches, as well as the establishment of dedicated mechanisms. Firstly, developing the bilevel programming of “generation-load-storage” for generalized power source flexibility will release their potential as new sources of flexibility. Secondly, studying the integrated planning of pooling and transmission systems at major renewable energy bases, a balanced generation-grid planning approach is proposed that takes into account the “semicontrollable” power characteristics of renewable energy (virtual units), establishing a hierarchical planning approach featuring on-site clustering and AC/DC transmission delivery. Finally, studying the multisite layout and optimal configuration of generation-side multisource energy storage, with the view to optimal coordination among the points/clusters based on the chosen energy storage capacity and spatially optimal deployment.