Electricity saving box or energy saving box or a.k.a power saver is a real scam. Many people became victim of this product. Advertisement said a 30-60% decrease in electric bill every month with matching demonstration that the current is actually become lesser when the electricity saving box is plugged in. Ordinary people (with no background in electrical or electronics
engineering or related discipline) are surely convinced by their lies.
As an electrical/electronic engineer, practitioner and hobbyist let me tell you and share a little education how this advertised electricity savings box works and to reveal its great scam.
Real Power – this is the true power each appliance consumes and this is the power considered by the electric utilities to charge to their customers.
Apparent Power – this is the total power including the power losses in the transmission lines or simply the power delivered by the electric utility.
Voltage (V) – this is the voltage coming out from the wall outlet
Current (I) – this is the current flow to the appliance or device once it is plug in to a wall outlet
Power Factor (PF) – this is the multiplier to the apparent power to get the real or true power
Let me do a little Math:
How the Energy Companies Charge Us on our Usage
The electric distribution companies are charging us through real power we consumed, not with the apparent power. The real power our appliances consumed is following equation 2 above which is the product of voltage, current and the power factor.
The electricity meter used by electric utilities is capable of detecting the voltage, current and power factor and able to compute for the real or true power consumption.
How Vendor Perform Demonstration on the Claimed Electricity Saving Box to Make People Believe Their Claim
Most of the times, the sales representative bring with him an electric fan and a multimeter. They use the multimeter to measure the current that drawn by the electric fan with and without the power saving box. Initially without the energy saving box, the current on the multimeter is high. The current measured once the energy saving box is plugged in is definitely lower than the initial current. Ordinary people are surely amazed and purchase one but they do not realize the savings as advertised!
Without the Electricity Saving Box plugged in, the current reading is high. Once they plugged in the box the current is much lower. They then concluded a big savings when using their product.
BUT WAIT…How they perform the demo? Are they showing evidence on actual power consumption with and without the box? What they did is only getting the current drawn by the appliance. They multiply the current to the voltage and claimed that this is the power consumed by the electric fan. This is not yet the real power consumed by the electric fan. The real power always includes the power factor on it as illustrated in equation 2 above.
Considering equation 2
Actually, the real power is fixed. For instance, an electric fan is rated 100W. 100W means a real power.
Let me re-write above equation
The real power is constant as well as the wall outlet voltage is fixed. Therefore, the above equation is only dependent to the power factor PF. The higher the power factor, the lower the current or the lower the power factor, the higher is the current. Without the energy saving box, the current will be high and it will be lower once the box is plugged in because the box itself is making the power factor higher.
On the demonstration, they are not emphasizing this. I don’t even think that these sales personnel know about power factor. They are not engineers or really skilled and knowledgeable on electricity related things.
You may challenge these persons to get a real power meter so that a real power will show. I am very sure that they don’t make it because they will be showing a constant real power drawn by the appliance.
Electric Companies are charging us by the real power we consumed. The real power is always composed of voltage, current and power factor not voltage and current only. If the current is high with a constant voltage, the real power will be the same since the power factor is low. If the current is low, do not be excited because the real power is still be the same since the power factor will be high.
Actual Experiment Conducted Proving that a Higher and a Lower Current will Result to the Same Real Power and Proving the Electricity Saving Box a Real Scam
Below table is an actual characterization results on a particular equipment power consumption (I am referring to the real or true power that will be read by the electric distribution company). I have three iterations wherein I changed the effectiveness of my power factor correction circuit or A.K.A. power saving device that we design for our products. The meter used here is Yokogawa WT310 digital power meter. The data in all columns are measured by Yokogawa WT310 digital power meter.
The first trial has worst power factor, so it has the highest current reading. The second trial registered an improved power factor thus the current decreases. The third trial has the best power factor of almost unity (the best case for power factor is unity).
It has the lowest current. However, observe the power consumptions, the three trials all have the same power consumptions of around 275 Watts. By multiplying the voltage (yellow column) and current (blue column) will not give the real power but an apparent power. Energy saving box advertiser do consider only the input voltage and the current drawn because what their multi tester reads are only voltage and current but no power factor. They put to the minds of the customer or audiences that the power the electric company read is simply the product of the voltage and current but it is not. A clearly dishonest and misleading demonstration.
The Reason Why an Energy Saving Box Don’t Live as Expected
Let us start by defining the operation of this claimed an energy saving box. It is simply a power factor correction circuit. A power factor correction circuit provides correction to the power factor so that the power delivered by the energy company is the same to the power that is actually consumed by the consumer. The ideal value of power factor is unity or 1. When the power factor is unity, this makes equation 1 and 2 equal. Majority of the consumer’s load are inductive in nature such as electric fan, aircon and washing machine to name a few. For inductive load, the power factor is always below 1. The claimed energy saver is actually a power factor correction that is most of the time a capacitive network to counteract the effect of naturally inductive load. As the power factor decreases, the current will increase. As the power factor increases, the current will decrease. However, the real power that is consumed by the equipment/appliance is the same. Real power cannot be measured by simply using a multi-meter as the advertiser did. Advertisers must use power factor meter to demonstrate the reality but I believe they will not make any move that will jeopardize their business.
The Real Function of a Claimed Power Saving Box
Energy saving box is actually a power factor correction circuit. It is a capacitive circuit to counter the effect of inductive loads (residential and industrial loads are mostly inductive in nature). It can be a passive or active solution. A passive solution is just a simple capacitive circuit and only effective for linear inductive circuits but with almost no effect on non-linear systems. On the other hand, active solution uses active devices or circuits to correct the circuit power factor. This is very effective for both linear and non-linear systems however very expensive and complicated.
Below is a waveform of voltage and current of an inductive circuit. As you can see, they are out of phase. The ideal case is for them to be in-phase. With this circuit, the apparent power will always larger than the real power. This is a disadvantage for electric companies since they are supplying more power than the customer actually consumed.
When a passive power factor is included or installed, the current and voltage will become in phase as below waveform. When this happens, the apparent power and the real power will be equal (ideally unity power factor). This is very good for electric companies as they do not waste power.
Below is the waveform of voltage and current of non-linear systems. Non linear systems include rectifier and switching converter. The shape of the voltage is intact (sinusoid) but the current is very distorted which emphasizes a very low power factor.
Considering the same power drawn by the end users, the effective value of the current will be high thus results to higher losses in the transmission lines and a big loss in the part of the electric company. With a power factor correction circuit installed (particularly an active PFC), the current shape will be corrected and restore its sinusoid shape the same above.
Whatever the rated power of your appliances, this is the real power that the electric companies will be charging to you. The rated power or the real power drawn by your appliances is always composed of the voltage from the wall outlet, the current and the power factor. Advertisers and vendors are only considering the voltage and current while neglecting the power factor.
Always remember, when current is high, the power factor is low that will result to a same real power. If the current is low, the power factor will be high which also result to the same real power. You can’t save by using energy saving box.
The use of electricity saving box does not give energy savings to consumers. Electric companies are the one directly benefited if residential use energy saving box. However, if all end users will use energy saving box, there will no extra fix losses on the transmission lines and the generation cost will be lower so residential do not shoulder it anymore. In this means, residential have savings (a very small savings) on the generation cost which is most of the times are on top of the actual energy consumptions. Do not buy the idea of saving up to 50% of the monthly bill using energy saving box because it is a scam and very dishonest claim.