Flywheels are well suited to specific applications for storing energy. A good example is seen in the video link below of my 3/4 horse electric woodsplitter; I call it the Electro-Split. It's very fast, very quiet, and the stored energy of the flywheels works well in the short duration of splitting. There are other types of mechanical splitter videos that also show the power of the stored energy in flywheel(s).
This flywheel storage also works extremely well in smoothing out powerstrokes and electric motor start-up when running the Listeroid.
~CrazyJerry
Electro-Split video:
Off Grid: Electro-Split - YouTube
Listeroid at 375 rpm:
375 RPM Diesel Generator - YouTube