Please correct me, and add to this.
There are two types of power, real (W) and reactive (VAR), when the amps and volts are in phase, the power factor will be 1 or unity. A resistive load will call for both the W and VAR to be in phase, thus the power factor will be 1. An inductive (motor) load will cause the volts to lag the amps, power factor will be less than 1. A capacative (capacitor) load will cause the volts to lead the amps and power factor will be greater than 1.
The power company must provide both W and VAR to handle the loads. It is most efficient to have the power factor be 1, thus the company does not have to generate and transmit any VAR's. Putting in capacitors that match the inductive (motor) loads will get the two in phase.
Most residential and commercial only get billed for the real power (KW), thus the utility eats the cost of the VAR's. Most industries have to pay for both W and VAR, or VA, so they are incentivized to reduce the VAR demand. This is done by adding capacitors. These capacitor banks are expensive, and have to be controlled by staging them on/off to get power factor as close to 1 as possible.
In the old days all motor loads where inductive, thus power factor was low, so adding capacitors was the answer. Now, a lot of industries are adding VFD's in front of the motors, so their natural power factor is 1, or sometimes greater than 1 which is leading. We are also seeing VFD's on modern air conditioning compressors so power factor on homes should also be closer to 1.
Please comment.
I hope I did not get leading/lagging backwards, it has been about 15 years since I worked with it.
There are two types of power, real (W) and reactive (VAR), when the amps and volts are in phase, the power factor will be 1 or unity. A resistive load will call for both the W and VAR to be in phase, thus the power factor will be 1. An inductive (motor) load will cause the volts to lag the amps, power factor will be less than 1. A capacative (capacitor) load will cause the volts to lead the amps and power factor will be greater than 1.
The power company must provide both W and VAR to handle the loads. It is most efficient to have the power factor be 1, thus the company does not have to generate and transmit any VAR's. Putting in capacitors that match the inductive (motor) loads will get the two in phase.
Most residential and commercial only get billed for the real power (KW), thus the utility eats the cost of the VAR's. Most industries have to pay for both W and VAR, or VA, so they are incentivized to reduce the VAR demand. This is done by adding capacitors. These capacitor banks are expensive, and have to be controlled by staging them on/off to get power factor as close to 1 as possible.
In the old days all motor loads where inductive, thus power factor was low, so adding capacitors was the answer. Now, a lot of industries are adding VFD's in front of the motors, so their natural power factor is 1, or sometimes greater than 1 which is leading. We are also seeing VFD's on modern air conditioning compressors so power factor on homes should also be closer to 1.
Please comment.
I hope I did not get leading/lagging backwards, it has been about 15 years since I worked with it.