Power density

For power per unit area, see surface power density.

Power density (or volume power density or volume specific power) is the amount of power (time rate of energy transfer) per unit volume.

In energy transformers like batteries, fuel cells, motors, etc. but also power supply units or similar, power density refers to a volume. It is then also called volume power density which is expressed as W/m³.

Volume power density is sometimes an important consideration where space is constrained.

In reciprocated internal combustion engines, power density- power per swept volume is an important metric.

See also

• Energy density energy per unit volume
• Power-to-weight ratio/Specific energy - energy per unit mass
  • Specific absorption rate (SAR)