Tuesday, May 17, 2011

how does energy saver works?

We often heard about energy saver or power saver. just plug it in a socket nearest to the meter and the electricity consumption goes down anywhere between 20% to 50%. Is it really works? what is the principle behind it??

In this post, i'll discuss in details the principle behind it and it is open for further discussion. just write down your comment/arguments at the comment part at the bottom of this page.

Do you actually need to install these power saver??- the answer can be YES or NO.
how do i know?
It is a YES if there is an additional sentence about SURCHARGE in the particulars column of your electricity bill.
It is a NO answer if there is no additional surcharge in your electricity bill.
There is a power factor surcharge by TNB when your average monthly power factor falls below 0.85. The lower your power factor, the higher the surcharge. The rates fixed by TNB are as follow:
(a) Below 0.85 to 0.75.....1.5% per unit
(b) Below 0.75..................3.0% per unit
The % total of (a) and (b) will be levied on your electricity consumption for the month.

these power saver helps to increase your power factor anywhere between 0.9 to 1.0. So, no more power factor surcharge you need to pay.

Why do i have such a low power factor?
We usually have a low power factor when there are a lot of inductive loads in our house. Any devices that have coils of wire can be classed as inductive loads. e.g. motors, solenoids and contactor coils, air condition, light bulb, florescent lamps, mixer,blenders,fan etc. In fact, most of our household appliances are inductive loads. These loads need to be balance using capacitive loads. So the power saver gadget is actually some kind of capacitive loads installed to balance the inductive-capacitive loads at our house so as to increase the power factor.

If I don't have any surcharge, why shouldn't i use power saver to save more?
Theoretically, there is no way you can save your electricity using the power saver gadget. Yes, it help to correct/improve the power factor, and this help you by eliminating the surcharge. We are being charge for the amount of real power been use in a month. Have you ever notice the 40Watt label on your florescent lamp when you buy them?- that label tells you the real power requirement for that lamp- and it is a fixed value. Let say you are using 100 lamps, 24hr-7days a week.how much it will cost you?

40watt X 100pcs X 24hr = 96kW per day = 96 X RM0.20 = RM19.20 per day

The only way you can reduce the RM you need to pay is to reduce the amount of lamp been use at a time.Why? because the 40Watt value is fixed and you still need to pay every time you use it.

notice that when you install a power saver gadget, it reduce the current consumption. Why?

consider the following equation

real power = current X volt X power factor

with the real power and volt fixed, improving the power factor(e.g from 0.8 to 1) will actually reduce the current. But still, you need to pay the same amount as TNB charge you for the amount of real power usage.

as a conclusion, you'd better check you bill before you decide to buy such device. in some situation, it might not benefit you, but it benefit the environment for more efficient power transfer to your house. efficient power transfer means, less loses, less fossil fuels use to generate inefficient power, less energy waste.

1 comment:

Anonymous said...

But I thought TNB charges power factor surcharge to business and industrial users only. This does not apply to residential users, right?