Transforming Classical Hydropower Generation for Flexibility in the Global Energy Transition: Challenges, Requirements, and Prospects
Yannick Cyiza Karekezi, Frédéric Maurer, Dany Josue Tome-Robles, Thomas Øyvang, Jonas Kristiansen Nøland
Abstract
This review article covers the multidisciplinary challenges shaping hydropower development within a broader energy transition. Classical hydropower generation facilities are moving toward flexible operations to adapt to and facilitate the integration of variable renewable energy sources (VRES). This review article explores the paradigm shift in terms of machine design considerations, power plant operation, and grid regulator implications. Machine designers, consider magnetic saturation, energy efficiency estimation, and mechanical wear and tear. This could involve, high flux densities in certain core regions, lower weighted average efficiencies, and higher machine failures owing to insulation degradation. Moreover, power plant operators must consider the effects of the flexible power production caused by VRES. In some cases, hydropower ramping ranges from 1 to 5 megawatts (MW) per second for large hydropower plants, which pose technical challenges for operators. In contrast, grid regulators must strengthen reactive power mandates and system-bearing services to ensure stability. In certain regions, there could be longer periods of 30 to 40 percent reduction in physical inertia owing to the lower share of traditional power plants in a VRES-dominated power system.