An inverter is a very useful appliance to provide power (or electricity) back-up during power-outage. It ensures a smooth continuity of electricity usage in whatever it is that one is doing, be it working on a computer or watching television or using washing machine etc, without any hindrance. As soon as the power from the utility disconnects, the inverter kicks in and provides power to the appliances.
But some manufacturers claim that inverters (manufactured by them) can save electricity. How accurate is this statement? Let us find out.
A little something about inverters
An inverter is basically a device which converts a Direct Current (DC) to Alternating Current (AC). It cannot provide electricity backup on its own. An inverter is one of the three components of a UPS (Uninterruptible Power Supply). These components are: a charger, a battery and an inverter. The assembly of these three components provides the power backup to appliances (and this assembly is what people generally call an “inverter”, however an inverter is only a part of this assembly. For the sake of understanding, we will call the assembly as the inverter henceforth). The charger is connected to the power supply of the home/office and it does the function of charging the battery, taking power from the mains. The battery is where the charge is stored which can be used later (or during a power outage).
Now an interesting thing to note here is that the charge that is stored in the battery is in the form of Direct Current (DC). And the appliances need Alternating Current (AC) for their functioning. This is where an inverter steps in the picture. It converts DC to AC and thus, makes the appliances run using the power from the battery.
For more information on inverters, please refer to the article “Choose right inverter for home and maintain it right to manage electricity bills”.
Inverters consume electricity
Although an inverter provides electricity backup to the appliances in a household or an office, but they consume some amount of electricity themselves. If a device converts all of the power it consumes to the output, then the device is said to be 100% efficient. An inverter can never be 100% efficient. There is always certain amount of loss associated with the functioning of an inverter. In other words, the moment you switch on an inverter, in addition to providing power to the connected appliances, there is also some amount of loss of electricity which the inverter experiences. In fact, there is also a certain amount of energy-loss even when it is not connected to the main power supply.
Typically it has been seen that the energy losses of the inverter vary proportionally with the size of the inverter. Bigger the size of the inverter, more will be the energy losses and smaller the size, the energy losses will be smaller. So if you buy an over-sized inverter thinking that it will provide power backup for a long time, then you should think again. Because although it will provide a good power backup, but being over-sized, it will also result in more energy losses.
Energy losses in an inverter
As we discussed above, the total input of electricity in an inverter does not get converted to power output for the appliances. The reason behind this is that there are some energy losses which take place in an inverter. These losses take place in the internal components of the inverter (which cannot be completely eliminated) due to charging/discharging of capacitors in batteries. Also, there are energy losses in the wires and losses due to trickle charging. Trickle charging refers to charging a battery under no load, even when it is fully charged. This results in some energy loss. All these losses have a combined effect on the total efficiency of the inverter.
Typically the efficiency of an inverter varies within the range of 85% to 95%. Also, it has been seen that the efficiency of an inverter increases with the increase in the connected load to a certain limit, and beyond that limit of the connected load, the efficiency of the inverter falls again. These values vary with different brands, and the type of the inverter one is using.
So if we take an example of a household having a total load of 1 kVA and using an inverter which is 85% efficient, then the energy loss will be 150 VA (which is approximately equal to 150 Watts). And if this inverter is used for 10 hours, then 1.5 units (approx.) will be lost.
Can inverters save electricity (energy)?
We all know that inverters provide power backup (which is great!). But can they also save electricity?
Microtek came up with an advertisement (you can watch it below) in which it is said that inverters can save electricity.
Inverters cannot “save” electricity.
The reason behind it is what we have discussed above. It is because there will always be some energy-loss that is associated with an inverter, be it of any manufacturer. In simple words, when the electricity passes through the inverter, there are some losses in the electricity, which cannot be entirely eliminated. However, the overall efficiency of an inverter A of a particular manufacturer can definitely be better than another inverter B of a different manufacturer, which means that the energy losses in one inverter can be lesser than energy losses in another. But energy loss in an inverter will always be there.
So from the above advertisement, it can be satisfactorily inferred that the said product can be more efficient than other inverters, but it cannot “save” electricity as such. It can only minimize losses.
An inverter (Uninterruptible Power Supply) can provide power backup when one needs it. Also an inverter can be made more efficient by making technical changes in the interior of the inverter. In short, the energy losses in an inverter can be minimised, but cannot be completely eliminated. .
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