Solving congestions with pumped hydro storage under high penetration of renewable energy in Vietnam: The case of Ninh Thuan HV grid

Renewable energy sources are increasingly penetrating all power networks worldwide, despite the security status of these networks threatened by the fickle nature of these sources. Ninh Thuan Province (Vietnam) experienced a solar power boom in 2019–2021 and, with it, the congestion of both the local transmission and distribution networks. To solve congestions and operational security issues, large-scale storage solutions were considered and, due to land availability, Pumped Hydro Storage (PHS) technology was selected to solve these problems. However, the operational risks of cascade outage when integrating both renewables and a PHS system needs to be carefully considered, especially in a bulk power system. For this reason, this study examined the potential of integrating a large-scale grid-connected PHS system in ensuring operational security against the impacts of solar power plants in Ninh Thuan. The analyses of static and dynamic security were carried out for scenarios with and without the PHS system, including under current operational conditions. The results of the simulations show that the presence of the PHS improves both static and dynamic performance of the system, thus allowing full exploitation of solar power and avoiding curtailment. NEPLAN environment was chosen to simulate all scenarios under the Vietnamese grid code.