Energy saving device - can they work?

[stacynewton]

Hi,
I've seen 'energy saving devices' on ebay, like the one below.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=320112306703&ssPageName=MERC_VIC_RSCC_Pr4_PcY_BIN_Stores_IT&refitem=320099585047&itemcount=4&refwidgetloc=closed_view_item&usedrule1=StoreCatToStoreCat&refwidgettype=cross_promot_widget

Any one know if these actually work?

Thank-you,
Stacy

[audioguru]

Hi Stacy,
Welcome to our forum. ;D
It is just a capacitor. If it is calculated to match the inductance of your running appliances then it reduces the power factor. Your electric meter does not measure power factor so you save nothing on your bill but your electrical utility company will use less power.

[stacynewton]

Thanks for the reply.

I'll come clean... I actually bought one of these  ::)

I have an electrisave monitor which monitors the amount of electricity used in the whole house and a socket meter.
When I plug the 'energy saver' into the socket meter it reads 0w used but the 'apparent power' used is about 100w. I don't really understand what the apparent power is or what power factor means but the electrisave monitor goes up by 50-100w when the 'energy saver' is pluged in.

I don't really understand this but does you think there is any point using this thing or is it likely to be doing more harm than good?

Any ideas apprieciated.

Thank-you

[audioguru]

Hi Stacy,
Your "energy saver" wastes power when it is plugged in and a matched inductive appliance is not running.
The wasted power is apparent power that is not measured by your billing electric meter.
Since your "electrisave monitor" shows apparent power then it is a false indication of any savings. The "energy saver" also gives false savings.

[Ldanielrosa]

If you have the means to do so, I would certainly like to see a picture of the guts of this device.

I don't know how they can claim to save any power with resistive loads like a range, toaster. or light bulb.  Does anybody reckon they are designed to deceive the meter by using an amp or two at peak and feeding it back at higher current near crossover?  If so it is illegal in several countries.

[audioguru]

If you have the means to do so, I would certainly like to see a picture of the guts of this device.

The ad says it reduces the power factor by the use of a "specially designed" capacitor. That is all.
Maybe in China you pay more for electricity if the power factor is bad due to inductive loads.

[AN920]

In a recent article it was calculated that the savings for an average household would be only 0.1% of the total monthly electric bill. For industrial applications with lots of motors it will pay over time.

[Herman the German]

If you have the means to do so, I would certainly like to see a picture of the guts of this device.

I don't know how they can claim to save any power with resistive loads like a range, toaster. or light bulb.  Does anybody reckon they are designed to deceive the meter by using an amp or two at peak and feeding it back at higher current near crossover?  If so it is illegal in several countries.

Hi again today Ldanielrosa,

I know about this stuff. They sell it in Thailand for a relatively high amount of money (about 32US$). My friend purchased such a thing and he gave me permission to open it. The box was glued together all over for good reasons. Inside there where three capacitors of 0.15MicroFarad/250VAC in parallel, a 470K resistor and a LED. There is no change in the meter plugging or unplugging it. It's just cheating!
Since the LED consumes electric power too the bill will increase.