© Florida Energy Conservation Advisors, Inc 2011
Power Factor
Correction
The Reactive Power
charge on your electricity bill is
directly targeted against those
companies who do not
demonstrate clear energy
efficiency use.
You will find this charge
itemized on your electricity bill.
Reactive power charges can
be made significantly smaller
by the introduction of Power
Factor Correction Capacitors
which is a widely recognized
method of reducing an
electrical load and minimizing
wasted energy , improving the
efficiency of a plant and reducing
the electricity bill. It is not always necessary to reach a power factor of 1.
A cost effective solution can be achieved by increasing your power factor to greater than 0.95
What is Power Factor?
Power Factor is a measure of how efficiently electrical power is consumed.
In the ideal world Power Factor would be unity (or 1). Unfortunately in the real world Power Factor is
reduced by highly inductive loads to 0.7 or less. This induction is caused by equipment such as
lightly loaded electric motors, luminaries transformers and fluorescent lighting ballasts and welding
sets, etc.
What does it do to my electricity bill?
In a 3 phase supply, kW consumed is (VOLTS x AMPS x 1.73 x Power Factor) / 1000.
The Electricity Company supply you VOLTS x AMPS and they have to supply extra to make up for
the loss caused by poor Power Factor. When the power factor falls below a set figure, the electricity
supply companies charge a premium on the kW being consumed, or, charge for the whole supply as
kVA.
What causes Power Factor to change?
Inductive loads cause the AMPS to lag behind the VOLTS. The wave forms of VOLTS and
AMPS are then "out of phase" with each other. The more out of phase they become then the lower
the Power Factor. In 3 phase power supplies the "power" can be measured as a triangle.
ACTIVE Power is the base line and is the real usable power measured in kW. REACTIVE power is
the vertical or that part of the supply which causes the inductive load.
The reactive power in is measured in kilo volt-amperes reactive. APPARENT Power is the
hypotenuse. This is the resultant of the other two components and is measured in kVA.