Explorer

Power Factor

billing and meteringv0.4.0Updated 2026-07-10

Canonical Definition

Power factor is the ratio of real power (kW) to apparent power (kVA) in an AC electrical system, ranging from 0 to 1, indicating how effectively current is converted into useful work. Low power factor, often caused by inductive loads such as motors, requires the utility to supply more current for the same useful power, increasing system losses and capacity needs. Many utilities apply power factor penalties or adjustments to commercial and industrial bills; residential customers are generally not billed for power factor.

Explanations

Power factor measures how well a building uses the power sent to it. The scale runs from 0 to 1. A low power factor means the utility must push extra current through its wires for the same useful power. That adds strain and cost to the system. Utilities often charge businesses a penalty for low power factor. Homes are usually not billed for it.

Analogy Bank

general

Power factor is like a horse pulling a barge at an angle — the more off-angle the pull, the more effort is wasted for the same forward motion.

general

It's like rowing technique: a power factor near 1 means almost every stroke actually moves the boat.

business-customers

For a business, low power factor is like a poor fuel-economy rating — the same useful output requires more delivered input.

Do Not Say

  • Do not state penalty thresholds or charges for low power factor; they vary by utility tariff.
  • Do not suggest residential customers buy power-factor correction gadgets or promise such devices save money; homes are generally not billed for power factor.
  • Do not give equipment-specific electrical advice; refer customers to a qualified professional.