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Power Factor Penalty Calculator

Monthly and annual demand penalty from a below-threshold power factor, plus the capacitor size and corrected kVA.

Inputs

Site and tariff

Billed peak real power in kW, from the bill or meter.

From the bill or a meter reading. Many utilities begin penalizing below 0.90 or 0.95.

Demand charge per kW of billed demand. Confirm whether your tariff bills kW or kVA.

Power factor the tariff requires before penalties apply.

Result

Annual penalty
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Capacitor size to correct (0 = already compliant)
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Monthly penalty (0 = no penalty)
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Apparent power now
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Apparent power at the threshold
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Billed demand under threshold-ratio billing
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What to check

  • The billing method from the tariff: threshold-ratio kW billing, direct kVA billing, and ratchets give different results.
  • Power factor from a meter or bill, not from nameplate ratings, and at the time of the billed peak.
  • The utility threshold, commonly 0.90 or 0.95, stated in the tariff as the point penalties begin.
  • Whether capacitors, a synchronous condenser, or an active filter is the right correction, and whether harmonics require a detuned bank.

Related calculators

Screens one common penalty method, threshold-ratio kW billing. Utilities also bill kVA directly or apply ratchets, and capacitor sizing must be checked against harmonics and switching requirements. Correction should be designed by a qualified engineer with metered power quality data.

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