Flywheel storage power system

A flywheel-storage power system uses a flywheel for grid energy storage, (see Flywheel energy storage) and can be a comparatively small storage facility with a peak power of up to 20 MW. It typically is used to stabilize to some degree power grids, to help them stay on the grid frequency, and to serve as a short-term compensation storage. Unlike common storage power plants, such as the pumped storage power plants with capacities up to 1000 MWh, the benefits from flywheel storage power plants can be obtained with a facility in the range of a few kWh to several tens of MWh.

Source: Wikipedia — Flywheel storage power system (CC BY-SA 4.0)