**How to Calculate Power Factor & Its Importance**

What Is Power Factor (PF)?
Power Factor (PF) is a measure of how efficiently electrical energy is used.
It indicates how much of the supplied electrical power is effectively utilized by electrical equipment.

The power factor value ranges from 0 to 1:

Close to 1.0 → efficient electricity usage

Low (e.g. 0.7) → high energy wastage

Power Factor Calculation Formula
Basic formula:

Power Factor (PF) = kW ÷ kVA

Where:

kW (Kilowatt) = Actual power used

kVA (Kilovolt Ampere) = Apparent power supplied

Simple Calculation Example
A premise uses:

Actual power = 8 kW

Apparent power = 10 kVA

Calculation:

PF = 8 ÷ 10 = 0.8

👉 This means only 80% of the energy is used effectively, while the rest is lost as reactive power.

What Is Reactive Power (kVAR)?
Reactive power is the energy required to:

Drive motors

Produce magnetic fields (air conditioners, machines, pumps)

It does not perform actual work, but it is still recorded in the electrical system.

Power relationship:

kVA² = kW² + kVAR²

Why Is Power Factor Very Important?
1️⃣ Reduce Electricity Bills
For commercial & industrial premises, TNB may impose penalties if the power factor is low.

2️⃣ Reduce System Load
Low power factor causes:

High current

Cables to overheat

MCB to trip easily

3️⃣ Extend Equipment Lifespan
An efficient electrical system reduces damage to motors and electrical equipment.

What Is a Good Power Factor Value?
Premise   Recommended Power Factor
House   > 0.90
Shop    > 0.85
Factory / Industry > 0.90