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Home / Technical Articles / The real truth behind household power savers
Household Power Saver
Household Power Saver - Efficent? What is the real truth?

A household power low voltage saving devices has recently received a lot of attention from both consumers and manufacturers. It is generally used in residential homes to save energy and to reduce electricity bills. It is a small device which is to be plugged in any of the AC sockets in the house (Mostly near Energy Meter). Moreover, some of the companies claim that their power savers save up to 40% of the energy.

Many people believe that the claims made by the power savers manufacturing companies are false. Almost all people who buy power savers do it to reduce their electricity bills.

Many people who have used these power savers said that they could reduce their electricity bills with the devices; however the reduction was not as much as they had expected. Moreover, they could not figure out if the reduction in electricity bills was due to the power savers or because of their efforts to reduce their electrical usage. There have been several serious discussions about the genuineness of the device.

In this note, we will try to find the real truth behind these power savers which claim to save as much as 40% of energy.

Working Principle of Power Saver as per Manufacture

A Power Saver is a device which plugs in to power socket. Apparently just by keeping the device connected it will immediately reduce your power consumption. Typical claims are savings between 25% and 40%.

It is known that the electricity that comes to our homes is not stable in nature. There are many fluctuations, raise and falls, and surges/Spikes in this current. This unstable current cannot be used by any of the household appliances. Moreover, the fluctuating current wastes the electric current from the circuit by converting electrical energy into heat energy.

This heat energy not only gets wasted to the atmosphere, but also harms the appliances and wiring circuit.

Household power saver device - Schematic diagram
Household power saver device - Schematic diagram

Power Saver stores the electricity inside of it using a system of capacitors and they release it in a smoother way to normal without the spikes. The systems also automatically remove carbon from the circuit which also encourages a smoother electrical flow. This means that we will have less power spikes. More of the electricity flowing around circuit can be used to power appliances than before.

Basically it is claimed that Power savers work on the principle of surge protection technology. Power savers work on straightening this unstable electric current to provide a smooth and constant output. The fluctuation in voltage is unpredictable and cannot be controlled. However, the power savers utilize current fluctuation to provide a usable power by acting like a filter and allowing only smooth current to pass through the circuit. Power savers use capacitors for this purpose. When there is a surge of current in the circuit, the capacitor of the power saver stores the excess current and releases it when there is a sudden drop. Thus only smooth output current comes out of the device.

Moreover, a power saver also removes any type of carbon in the system, which facilitates further smoother flow. The main advantage of power savers is not that they provide a backup system in times of low current, but that it protects the household appliances. It is known that a sudden rise in the power can destroy the electrical appliance. Thus, the power saver not only protects the appliance but also increases its life. Moreover, they also reduce the energy consumption and thus the electricity bills.

The amount of power saved by a power saver depends on the number of appliances on the electrical circuit. Also, the system takes at least a week to adapt itself fully to the circuit, before it starts showing its peak performance. The maximum amount of voltage savings will be seen in areas where in the current fluctuation is the highest.

Household Power Saver Scam Review

Power Factor Correction for residential customers (home owners) is a scam? At most, each unit is worth as an investment. Power factor correction does make sense for some commercial / industrial customers.

Many companies are promoting and advertise that their Power Saver unit are able to save domestic residential power consumption by employing an “active power factor correction” method on the supply line. The concept seems pretty impressive as the concept is true and legally accepted. But practically, we will find that it’s not feasible.

To support above statement first we need to understand three terms:

  1. Type of electrical load of house,
  2. Basic power terminology (KW, KVA, KVAR).
  3. Electrical tariff method of electricity company for household consumer and industrial consumer.

There are basically two kinds of load that exists in every house: one that is resistive like incandescent lamps, heaters etc. and the other that’s capacitive or inductive like ACs, refrigerators, computers, etc.

The power factor of a Resistive Load like toaster or ordinary incandescent light bulb is 1 (one). Devices with coils or capacitors (like pumps, fans and florescent light bulb ballasts)-Reactive Load have power factors less than one. When the power factor is less than 1, the current and voltage are out of phase. This is due to energy being stored and released into inductors (motor coil) or capacitors on every AC cycle (usually 50 or 60 times per second).

There are three terms need to be understand when dealing with alternating (AC) power.

  1. First Term is kilowatt (kW) and it represents Real power. Real power can perform work. Utility meters on the side of House measure this quantity (Real Power) and Power Company charge for it.
  2. The second term is reactive power, measured in KVAR. Unlike kW, it cannot perform work. Residential customers do not pay for KVAR, and utility meters on houses do not record it too.
  3. The third term is apparent power, referred to as KVA. By use of multi meters we can measure current and voltage and then multiply the readings together we get apparent power in VA.
Power triangle
Power triangle

Power Factor = Real Power (Watts) / Apparent Power (VA)

Therefore, Real Power (Watts) = Apparent Power × PF = Voltage × Ampere × PF.

Ideally a PF = 1, or unity, for an appliance defines a clean and a desired power consumption mostly Household Equipments (The dissipated output power becomes equal to the applied input power).

In the above formula we can see that if PF is less than 1, the amperes (current consumption) of the appliances increase, and vice verse.

With AC Resistive Load, the voltage is always in phase with the current and constitutes an ideal power factor equal to 1. However, with inductive or capacitive loads, the current waveform lags behind the voltage waveform and is not in tandem. This happens due to the inherent properties of these devices to store and release energy with the changing AC waveform, and this causes an overall distorted wave form, lowering the net PF of the appliance.

Manufacture claim that the above problem may be solved by installing a well-calculated inductor/capacitor network and switching it automatically and appropriately to correct these fluctuations. A power saver unit is designed exactly for this purpose. This correction is able to bring the level of PF very close to unity, thus improving the apparent power to a great extent. An improved apparent power would mean less CURRENT consumption by all the domestic appliances.

So far everything looks fine, but what’s the use of the above correction?

The Utility Bill Which We pay is never based on Apparent Power (KVA) but it is based on Real Power (KW). The utility bill that we pay is never for the Apparent Power- it’s for the Real Power.

By Reducing Current Consumption Does Not Reduce Power Bills of Household Consumer.

Study of Power Saver in Domestic Load

Let us try to study Household’s Reactive-Resistive Electrical Load and Voltage Spike Characteristic by example.

1. Power Saver in Reactive Load of Home

Let’s take One Example for reactive Load: A refrigerator having a rated Real Power of 100 watts at 220 V AC has a PF = 0.6. So Power=Volt X Ampere X P.F becomes 100 = 220 × A × 0.6 Therefore, A = 0.75 Ampere

Now suppose after Installing Power Saver if the PF is brought to about 0.9, the above result will now show as: 100 = 220 × A × 0.9 And A = 0.5 Ampere

In the second expression we clearly show that a reduction in current consumption by the refrigerator, but interestingly in both the above cases, the Real Power remains the same, i.e. the refrigerator continues to consume 100 watts, and therefore the utility bill remains the same. This simply proves that although the PF correction done by an energy saver may decrease the Amperage of the appliances, it can never bring down their power consumption and the electric Bill amount.

Reactive power is not a problem for a Reactive Load of Home appliances like A.C, Freeze, motor for its operation. It is a problem for the electric utility company when they charge for KW only. If two customers both use the same amount of real energy but one has a power factor of 0.5, then that customer also draws double the current. This increased current requires the Power Company to use larger transformers, wiring and related equipment.

To recover these costs Power Company charged a Penalty to industrial customers for their Low power factors and give them benefits if they improve their Power Factor in. Residential customers (homes) are never charged extra for their reactive Power.

2. Power Saver in Resistive Load of Home

Since a resistive load does not carry a PF so there is not any issue regarding filtering of Voltage and Current, So Power = Voltage X Current.

3. In Voltage Spike / Fluctuation condition of Household Appliances

In above discussion simply proves that as long as the voltage and the current are constant, the consumed power will also be constant. However, if there’s any rise in the input voltage because of a fluctuation, then as explained above your appliances will be forced to consume a proportionate amount of power. This becomes more apparent because current, being a function of voltage, also rises proportionately. However, this rise in the power consumption will be negligibly small; the following simple math will prove this.

Consider a bulb consuming 100 watts of power at 220 volts. This simply means at 240 volts it will use up about 109 watts of power. The rise is just of around 9% and since such fluctuations are pretty seldom, this value may be furthermore reduced to less than 1%, and that is negligible.

Thus the above discussions convincingly prove that energy savers can never work and the concept is not practically feasible.

What happens when Power Saver is installed?

The Fig shows the result of using Power Saver. The air conditioner (which has a large compressor motor) is still consuming reactive power but it is being supplied by a nearby capacitor (which is what is in those “KVAR” boxes). If you were to mount it at the air conditioner and switch it on with the air conditioner plus you sized the capacitor perfectly, then there would be no reactive power on the line going back to the fuse panel.

If the wire between your fuse panels is very long and undersized, reducing the current would result in it running cooler and having a higher voltage at the air conditioner. These savings due to cooler wiring is minimal.

What happens when Power Saver is installed
What happens when Power Saver is installed

A further complication is that if you install the “KVAR” unit at the fuse panel, it does nothing for the heat losses except for the two feet of huge wire between the fuse panel and the utility meter. Many KVAR units are marketed as boxes that you install at a single location.

If your power factor box is too large, then it will be providing reactive power for something else, perhaps your neighbor.


Power factor correction devices improve power quality but do not generally improve energy efficiency (meaning they would not reduce your energy bill). There are several reasons why their energy efficiency claims could be exaggerated.

First, residential customers are not charged for KVA – hour usage, but by kilowatt-hour usage. This means that any savings in energy demand will not directly result in lowering a residential user’s utility bill.

Second, the only potential for real power savings would occur if the product were only put near in the circuit while a reactive load (such as a motor) were running, and taken out of the circuit when the motor is not running. This is impractical, given that there are several motors in a typical home that can come on at any time (refrigerator, air conditioner, HVAC blower, vacuum cleaner, etc.), but the Power Saver itself is intended for permanent, unattended connection near the house breaker panel.

And certainly not in the way the manufacturers recommend that they be installed, that is, permanently connecting them at the main panel. Doing that drags the power factor capacitive when the inductive motors are off and could create some real problems with ringing voltages.

The KVAR needs to be sized perfectly to balance the inductive loads. Since our motors cycle on and off and we don’t use the air conditioner in the winter, there is no way to get it sized properly unless we have something to monitor the line and switch it on and off capacity (capacitors) as necessary.

Adding a capacitor can increase the line voltage to dangerous levels because it interacts with the incoming power transmission lines. Adding a capacitor to a line that has harmonic frequencies (created by some electronic equipment) on it can result in unwanted resonance and high currents.

For commercial facilities, power factor correction will rarely be cost-effective based on energy savings alone. The bulk of cost savings power factor correction can offer is in the form of avoided utility charges for low power factor.

Energy savings are usually below 1% and always below 3% of load, the higher percentage occurring where motors are a large fraction of the overall load of a facility. Energy savings alone do not make an installation cost effective.

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Jignesh Parmar

Jignesh Parmar has completed M.Tech (Power System Control), B.E (Electrical). He is member of Institution of Engineers (MIE), India. He has more than 20 years experience in transmission & distribution-energy theft detection and maintenance electrical projects.


  1. Ray
    Sep 29, 2022

    I purchase 2 electricity saving spike buster last year and in this short time they have both appear to have stopped working.
    The green light does not come on any more.
    Apparently they are out of warranty.
    A waste of money…………….

  2. Bill Bradshaw
    Sep 12, 2022

    What power companies are charging/penalizing for poor power factor on a residential service? Sure, it could help with some of your motor loads, but like pointed out by another writer, you only clean half of the circuit with a plug in unit. You would need two and be sure to plug into each leg of your 240v circuit. Waste of money.

  3. Donn Hilton
    Sep 09, 2022

    People should understand that all homes have two phases of power coming to their home. Each phase is 120 volts and go to your basic wall outlets and your lighting. Combined the phases make 240 volts which go to things like your electric stove, water heater, that sort of thing. If you are to correct the power factor then you have to do it for both phases. By plugging a little unit into one outlet that will only do half the job. Power factor correction for industrial applications has been around for over 50 years.

  4. Peggy Moore
    Jul 30, 2022

    Thank you all for the information, especially Trevor Tesswood who cued me in that the previous comment was a joke. I am trying to reduce expenses in my home and was looking at one of the devices for sale. It mostly sounded logical but there were things that made me doubt it’s value. For one thing I do not trust the phrase “up to”. If one is guaranteed to loose up to 10 pounds, loss of even 1/4 pound meets the “up to” criteria. I was glad to locate this post where the item was discussed without brand names. I almost understood most of it as all technical terms were explained. Thank y’all again. I am not going to purchase the energy saver. ….and I am not going to look up neutrinos.🙂

  5. Hal Marston
    Jul 11, 2022

    Thank you, Jignesh.

    I have often wondered if you could efficiently address whole house or facility power surge, drag (dip in supply) and demand change requirements with a jumbo UPS (Uninterrupted Power Supply) essentially an in-line, main, recharging battery array or some other storage method.

    The key word is “efficiently” and the special problems ROI (Return on Investment), durability, scale, size and safety present. Any thoughts?

  6. Cindi
    Jun 13, 2022

    Like I can ever even understand that article. Greek to me.

    Jun 03, 2022

    Hi. Tks for this excellent article.
    In our country, more and more “intelligent power counters” are installed in households. People don’t rely on them and are thinking they can be fit by the Energy Supply Company to increase their bills as they want.
    What does exactly “intelligent counting devices” mean ?
    Sorry for my approximated english.

  8. Malcolm
    May 25, 2022

    Thanks for all the info. Obviously not worth buying. Too good to be true

  9. Finn Harder
    Apr 17, 2022

    I wholeheartedly agree. Remove carbon indeed?

  10. Larry b
    Apr 06, 2022

    It “removes carbon from the system”????

    Utter bollocks.

  11. Richard Dennis Muller
    Apr 01, 2022

    Hello Everyone,

    All electrical systems are different in people’s homes due to the many electrical contractors that have to install the systems differently and use different electrical equipment due to patents. Some will save 0% and some will save 90%. This leads to chaos which leads to stability. Read chaos theory on the internet. I have installed a power saver and I also have solar panels. My power saver is allowing my solar panels to produce electricity at night with solar neutrinos in addition to daylight. Look up neutrino solar panel technology. My solar panels are manufactured as neutrino solar panels. Some solar panels will not work to produce power at night. I produce 6500 kWh/year with sunlight and 8500 kWh/year with solar neutrinos. A person needs a specific type of solar panel and power saver to produce power at night with their solar system and neutrinos. I currently save 30% on my electrical bill because of this. My question is are there any people in the US who also experience this? I am writing a science paper on this and I am going to publish it if I can find 100 people who experience the same thing. If you want more information then contact me at my email address of [email protected]. I have found out that if someone pays a lot for their solar panels then they might experience the same thing that I do and if they paid less for their solar panels then they might not experience this due to the less expensive solar panels not being manufactured to provide this benefit. My theory is that everyone eventually pays the same amount for their electricity over time no matter what they do.

    • Trevor Tesswood
      Jun 21, 2022

      Okay, you really had me with the whole fake science thing about neutrinos. I thought you were just a bit psychotic.
      And then I saw the date that you posted this. You had me chuckle when I realised what you were doing.
      Any luck with recruiting the 100 lunatics?
      Very very funny.

  12. ANAND
    Nov 17, 2021

    What is the benefit of smoothening of the power cycle ?

  13. Bong
    Nov 04, 2021

    India Just Accept that China has Better idea from nowadays😅
    And i understand you recieved a lot of money from power company in india just to give a bad side of this device. Because many electric companies afraid if every consumer using this device n u know what happened😅

    • Donald Kelly
      Jan 18, 2022

      Jingnesh is right, These ‘home power savers” are not worth buying -particularly when placed near the meter. There are many claims for these devices that are nonsense. They take some known information and then go into fairyland.. Some try to tie them to Tesla, who was a 3 year old when the principle was first analyzed.. Another has a 300KW rating but plugs into an ordinary 15A 120V socket ..

      • Donald Kelly
        Jan 27, 2022

        With regard to my last comments, The monetary benefit depends on how your electric cost are determined by the type of meter in use..Some meters only record real power. (or are set to do this. My home meter is electronic but I am billed only on KWH. Other meters measure KWH as well as maximum KVA in a time (typically 20 t030 minutes). Originally these were not used for homes, but now,in high demand homes and cheaper meters that may be done by some utilities..
        All the graphs that are presented, do not show the instantaneous power in a cycle (60 cycles/msecond). nor do they show that the average over a cycle
        Check your bill.If it shows only KWH related information -there is no effect on the bill. If there is both KWH and Max KVA, there is a monetary saving.due to a better power.factor.

        • Douglas Daw
          Jun 29, 2022

          Extremely interesting (and entertaining) discussion. Theory and beliefs and between the lines, facts…
          an education!

    • Donald Kelly
      Feb 04, 2022

      Jignish is telling facts based on science, Electric companies are not afraid of this device. Power factor improvement for typical homes isn’t worth while . The principles, on which these devices are based , are well known (since before Kepler, who first presented a mathematical analysis when Tesla was 4 years old.).. Those who have a knowledge of basic electric circuit analysis see the scams.

  14. William bird
    Oct 27, 2021

    How do I order?

    • ru ko
      Mar 04, 2022

      Don’t order! Read the above comments. Do some research on the net. Google it. These devices are nothing but cheap capacitors in a fancy box. A total scam. Power companies are not afraid of them. They actually like them because they raise their power factor.

  15. ROBERT
    Oct 10, 2021

    Well I read all the negative reviews but I must disagree; they actually worked GREAT for me. I have a small house (650 sq’) and I just got a notice that my 12 month averaged bill is going from $140 a month to $105 a month, based on a 6 month review. I noticed a 19% reduction the first few months after installation (2), but now it’s at 25% reduction. I have 2 AC window units, and a stand alone indoor AC, used moderately this past summer. And a oxygen Concentrator that runs 8 hours a night. They refunded me $43.75. Which almost paid for the 2 that I bought ($50). Now I notice the same units are selling at WMT for $10 – LOL. Saving 25% each month is fine with me !!

    • ANAND
      Nov 17, 2021

      Interesting. Could you please share more information about the make of the instrument , power rating etc ?

      • Tom Crowder
        May 15, 2022

        So cutting to the chase do electrical power savers save energy consumption in a typical 3 bed home

    • Donald Kelly
      Jan 26, 2022

      Does the outside temperature vary over the year? It takes a lot ore energy to cool from 90F to 70F than it takes to cool from 75 to 70. This will have much more of an effect on your bill than the “power saver” . I assume the indoor AC unit has a tube to vent the air out of the room. If not, it is putting more heat into the room than it takes out. This is basic thermodynamics.

    • Chia doe
      Mar 30, 2022

      650 sf w/electric bill of $104? Seems high, I have 1200 sf (plus 1000 sf basement) with $70 average monthly bill (all electric – includes heat – no oxygen machine). I use one 5,000 btu window AC and two dehumidifiers and space heaters in mid Missouri.
      Depends where you live but I’d try to insulate more.

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