Energy Saving by Improving Harmonics

Don't even go there. It's a scam.

Reducing Harmonics will result in reduction in Iron losses which in turn will save input energy. Harmonics results in poor power factor. Thus reduction in Harmonics will improve power factor and hence less KWH.

Harmonics has two effect on system

1. Iron & Copper Losses

2. True power factor.

The advantage of having Harmonic filter depends upon the level of harmonics in the power system. By thumb rule if you harmonic more than 30% then it makes payback period more attractive. Otherwise you not worth it.

There are two type of harmonic filters

1. Passive Filter

2. Active filters

Right combination of two makes the filtering solution more attractive. I personally installed many harmonic system in various industry in india and abroad.

Hope this helps you.

Thanks

Paras

If you can eliminate harmonics, you may save the energy it would take to replace the equipment damaged by the harmonics.

Harmonics are caused by using the available AC power in a non-sinusoidal way. A simple full wave bridge yields both halves of the sine wave in the same polarity. Smoothing that out with a capacitor results in a circuit that only draws current when the incoming voltage is greater than the charge on the capacitor. So if your fundamental power frequency is 60 Hz, the bridge experiences gulps of current to recharge the capacitor at the rate of 120 times per second.

Each gulp has a start and stop transition that is very uncharacteristic of the fundamental frequency. The best way to avoid that is a different, more complicated, circuit. Filters may block or shunt some of the non-fundamental stuff but there is no energy to be saved.

It may be possible to save a little energy by using the AC power more efficiently which has the result of reducing harmonics . But the reverse is not true. That is to say that tolerating substantial harmonics by using filters on everything else is avoidance, not energy savings.

Power factor correction is an financial opportunity for big users of power. The little devices for home owners to use are insignificant, unneeded, and ineffective.

When guest says 30% of harmonics, he (must) means "with respect to the feeder capacity" not to the fundamental current being drawn by the load(s).

Example. If you have a "bad" load drawing 50% THD-I as measured by a power meter connected to it, this as a negligible effect if the current drawn is 50A on a 1000A feeder. To know if it is important, you must scale the THD-I measured by the ratio of the feeder capacity. In this case 50A/1000A*50%= 2% TDD-I (Total Demand Distortion). Absolutely not worth looking at potential savings in this case.

In Canada, the electricity is so cheap and we need to heat the buildings many month in the year. This almost minimizes the savings from PF or harmonics correction. The only reason we do it is to protect sensitive equipment and to optimize the KW available from the installed power feeder.

In your case, if you have to cool the buildings most of the year and the electricity is expensive, the economics are different. But don't worry too much if the Pf is above 0.9 and the Total Demand Distortion is below 10%. Any correction equipment can bring more costs than savings. Be careful.