  Frequency stability of power systems becomes more vulnerable with the
increase of solar photovoltaic (PV). Energy storage provides an option to
mitigate the impact of high PV penetration. Using the U.S. Eastern
Interconnection (EI) and Texas Interconnection (ERCOT) power grid models, this
paper investigates the capabilities of using energy storage to improve
frequency response under high PV penetration. The study result helps to
identify the potential and impact factors in utilizing energy storage to
improve frequency response in high renewable penetration power grids.
