Flywheel Energy Storage Calculator

Your details

The geometric constant k describes how mass is distributed. A rim-loaded wheel (k = 1) stores more energy per kilogram than a solid disk (k = 0.606) of the same mass and radius.
Total mass of the flywheel.
kg
Outer radius of the flywheel (half the outer diameter).
m
Revolutions per minute of the flywheel at full charge.
RPM
Ultimate or yield tensile strength of the flywheel material. Used to compute the theoretical specific energy limit (E/m = k * sigma / rho). Leave at 0 to skip.
MPa
Density of the flywheel material in kg/m³. Required with tensile strength to compute specific energy. Leave at 0 to skip.
kg/m³
Stored energyMedium-scale flywheel
134,572.1J

Kinetic energy stored in the spinning flywheel (E = 0.5 × I × omega²)

Stored energy (Wh)37.3811Wh
Moment of inertia2.727kg·m²
Angular velocity314.159rad/s
Rim surface speed94.25m/s
Stored Energy (J)134,572.1
Moment of Inertia (kg·m²)2.727
Rim Speed (m/s)94.25

This flywheel stores 37.3811 Wh at 3000 RPM.

  • The flywheel stores 134572.1 J (37.3811 Wh) of kinetic energy at 3000 RPM.
  • The moment of inertia for a Flat solid disk is 2.7270 kg·m².
  • The angular velocity is 314.16 rad/s and the rim surface speed is 94.25 m/s.
  • Enter the material tensile strength and density to unlock the theoretical specific energy limit for your chosen material.

Next stepTo increase stored energy, raise the rotational speed (energy scales with RPM squared) or use a rim-loaded geometry for a higher geometric constant k.

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