Synchronous condensers and grid flywheels are two different things, the former is synchronous, hence rpm locked to instantaneous grid frequency. These provide v

Synchronous condensers and grid flywheels are two different things, the former is synchronous, hence rpm locked to instantaneous grid frequency. These provide very short term stability, and are not energy storage (due to the small acceptable variance in grid frequency), and are normally used for dynamic grid-scale PFC. Flywheels are asynchronous and inverter-driven.