Exploring the transition role of cascade hydropower in 100% decarbonized energy systems

• Published in: Energy (Oxford) Vol. 279; p. 128086
• Main Authors: Jin, Xiaoyu, Liu, Benxi, Liao, Shengli, Cheng, Chuntian, Jurasz, Jakub, Zhang, Yi, Lu, Jia
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.09.2023
• Subjects: Assessment framework; Flexibility options; Hydro-based system; Low-carbon energy systems; Natural ‘battery’ role of hydropower; Natural ‘battery’ role of hydropower; Low-carbon energy systems; Assessment framework; Flexibility options; Hydro-based system
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2023.128086

Hydropower can be a renewable and alternative flexible option to support large-scale variable renewables integration, but the natural ‘battery’ role of cascade hydroplants remains unclear in decarbonization. Here, we present a multiscale assessment framework based on chance-constrained programming to quantify the changing role of hydropower in low-carbon energy systems. The framework includes optimal coordination expansion and base expansion models corresponding to the changing ‘battery’ and original power supplier, respectively. In addition to modeling operations of run-of-river hydropower, along with wind, solar, and coal and storage, the models, consider detailed hydraulic and electric coupling characteristics of cascade hydroplants and are transformed into mixed integer linear programming. Applying this approach to Yunnan clean energy system in Southwest China, we established that hydropower plays a crucial role in decarbonization by implementing comparative numerical experiments characterized by variable renewables penetration levels, hydrological years, and carbon emission levels, namely: 1) Compared with the current operation mode, the transformable hydropower could potentially decrease 14 GW storage investment and 6 GW of coal utilization by strategic hydropower operation. 2) Hydropower could reduce the triggering of other flexibility options by providing multiscale flexibility. 3) Decarbonization costs are expected to decrease by 36.6% on the path to zero carbon. •A multiscale assessment framework for hydro-based energy systems is designed.•A solution approach for complex constraints is proposed.•The changing role of hydropower for planning is quantified.•This study provides a useful case to inform hydropower's role in other regions.