Voltage optimizers

Pipsaholic

Hi,

Anyone got one? They claim to reduce your bill by 20% neutralising the incoming voltage from the grid.

                               
Cost about £200-300.

Thanks.

Chris Muriel

Marketing by only mentioning selected points.
See 10 eco products you don't need - Energy saving products - Which? Energy

Many modern devices efficiently drop the voltage using DC/DC converter ICs (integrated circuits) so not much is wasted in heat.
Additionally "closed loop" devices, which includes ovens and most heaters (anything which includes a thermostat) won't normally use less power at lower AC voltage input; they control themselves by switching off the heating when the preset thermostat "trip" temperature is reached.
  At lower voltages, theses devices may need to be fully on (and therefore drawing maximum current) for longer and so may actually result in more overall electricity used !

Trollslayer

I'd like to see how this is supposed to work.
If the voltage is lowered something like an oven will simply take longer to reach temperature or not reach it at all. The same power (perhaps a little more due to greater losses of heat over a longer time) will be needed.
For modern electronics such as a TV, they step down the voltage anyway.
An article in the Telegraph:
Jeff Howell's DIY advice: home voltage optimisers - Telegraph
"The drawback of domestic voltage optimisers is that they are a waste of money".
As the article says, filament bulbs will use less electricity but also produce less light.

Sonic67

The other thing is that appliances are designed to work at the correct voltage. If you reduce the voltage to a filament bulb (and who uses theses nowadays?) you will get less light but its life should also increase. However, it will not work out as good overall as if it always was fed the correct voltage. If you want to save money and have filament bulbs either fit lower wattage bulbs or use dimmer switches or these days switch to LEDs anyway.

Markee

The way these work is that all (ok, most) mains electrical devices are designed to operate at the standard EU voltage of 220v AC (single phase).

The UK mains voltage is 230v AC, which is allowed to fluctuate by  /- 10%.

As the devices are designed to work at 220v, any voltage over this will be disguarded as waste heat.

So, if your oven is operating at 220v, no it won't take longer to heat up, it will take the same time but you won't be chucking away the excess voltage as wasted heat.

That's the theory anyway......

Markee

....watch it though, the savings claimed by VO vendors are often very optimistic when compared with actual savings made.

Markee

More explanation here:

Voltage optimization: How it works - Explain that Stuff

Trollslayer

An oven is meant to produce heat so 'wasted heat' is a meaningless term with respect to voltage.
The wasted heat with an oven is through thermal leakage which is a function of temperature not voltage.
Remember that the oven goes to a set temperature, it doesn't go to a lower temperature because of lower voltage unless the voltage is so low that it cannot get up to temperature.
The equipment which will benefit will be that which uses a linear transformer based power supply and has a function which is not based on the amount of power it can generate.
The thing is that switch mode power supplies are so easy these days that linear power supplies are pretty rare.
Looking around me I can't think of anything here other than lights which would reduce power consumption with a reduced supply voltage.

Markee

Sorry, I meant wasted energy (which is lost as heat).

Markee

Hit the nail on the head, savings from VO are very limited in domestic installations.