Voltage optimizers any good?

[spynage]

Hi.

Are they any good and how do they work? Do they lower the voltage across the board? If so what about appliances that use more than 220v?

Thanks

Spynage

 

[UNG]

Been discussed on here and other forums numerous times and often referred to as snake oil by some members the consensus was they did not work back then and they still won't work now

 

[davesparks]

They work in so far as they reduce the voltage, they don't work in so far as they don't reduce energy consumption by any appreciable amount.

I have fitted one of these voltage optimiser/stabiliser units in a situation where the incoming supply voltage was sitting at 250V and the installed equipment was designed for 230V and was regularly failing due to the over-voltage.

 

[spynage]

They work in so far as they reduce the voltage, they don't work in so far as they don't reduce energy consumption by any appreciable amount.

I have fitted one of these voltage optimiser/stabiliser units in a situation where the incoming supply voltage was sitting at 250V and the installed equipment was designed for 230V and was regularly failing due to the over-voltage.

Thanks. I've since done a bit more reading. According to this report they save you about 6% a year. >> https://www.ofgem.gov.uk/sites/defa...-saving-trial-report-for-the-vphase-vx1_0.pdf

 

[davesparks]

Thanks. I've since done a bit more reading. According to this report they save you about 6% a year. >> https://www.ofgem.gov.uk/sites/defa...-saving-trial-report-for-the-vphase-vx1_0.pdf

That still doesn't look all that great, especially when some of the installations appear to have negative figures for energy savings

 

[James]

i can understand how they COULD SAVE 6% per year on lighting, IF you are using filament lamps.
however, it will save nothing on lighting if you are using LED lamps.
motors will use the same amount of power regardless of the voltage (within reason) as they will use more current as the voltage drops.

I am personally holding them in the snake oil category unless there are some particular site specific issues that mean the voltage rises well above nominal 230V.

incidentally, if you have ac motors, reducing the voltage to them would mean a higher current and a larger heat generation inside the windings therefore reducing the lifespan of the motor.

If you install one, please wait for 3 months, have some good evaluation of the consumption and then do an identical evaluation for 3 months afterwards and post the results here, it MIGHT be the first real life proof that they save energy!!

 

[UNG]

If you install one, please wait for 3 months, have some good evaluation of the consumption and then do an identical evaluation for 3 months afterwards and post the results here, it MIGHT be the first real life proof that they save energy!!

I wouldn't bother there are too many variables to create an exact same useage profile over two 3 month periods, I would think even doing it under laboratory conditions would prove difficult to replicate

 

[pc1966]

That report was from ten years ago, I suspect a lot more fluorescent and filament lamps in use.

I suspect you could save a lot more by going down to route of replacing any non-LED lamps with suitable LED equivalents, switching off stuff that has no actual need to be on standby, and making sure stuff is not left on when not needed (as many public building now do with movement sensors for hallway and bathroom lighting, etc).

Not to mention turning down heating to the minimum acceptable for folks wearing jumpers (not like a certain family member of mine who complained in the past of high bill but insisted on going around in a T-shirt, etc, during winter with heating to match).

 

[pc1966]

Just to add that for many traditional loads reducing the voltage will reduce the power consumed, but if you are trying to achieve a specific work-related goal, for example, heating water to a certain temperature, then the system will use the same (or even slightly more) energy to do so, it will just take longer.

In the case of old style lights then yes you would lower energy consumption as they are normally on for a fixed time, not a fixed work load, but they would be slightly dimmer.

As already mentioned above, for many electronic loads such as LED drivers, PC/TV power supplies, etc, they draw essentially the same power over the whole operating voltage range. Efficiency of the PSU might very a little as the V/I trade off changes, but a lower voltage is going to increase I2R losses somewhere.

Too high a voltage can damage stuff or reduce its lifetime so there can be other reasons to consider a device like this (or a UPS that provides other benefits) but I personally would not see such a device as a good way of spending money compared to the more direct options to reduce wasted power.

 

[pc1966]

Graph half way down here shows PC PSU is actually best efficiency at higher voltages:

Intel’s ATX12VO Standard: A Study In Increasing Computer Power Supply Efficiency

The venerable ATX standard was developed in 1995 by Intel, as an attempt to standardize what had until then been a PC ecosystem formed around the IBM AT PC’s legacy. The preceding AT form fac…

hackaday.com

 

[stevethesparks]

Once car chargers and electric boilers are the norm, optimisers will be redundant.

 

[Lucien Nunes]

Good info above, all homing in on the main issue which is that different kinds of equipment react in different ways to the lower voltage, with only a small fraction of typical loads improving in efficiency as the voltage reduces. Three typical effects would be:

1: Uses the same amount of energy to produce the same results; e.g. thermostatic heater compensates for lower heat output by staying on longer, SMPSU uses almost constant power input.

Less frequently:
2: Uses less energy but produces less results; e.g. tungsten lamp gets dimmer, actually gets less efficient because the percentage loss of light output is greater than the percentage energy saved.

And finally the one the the VO sellers want you to believe, but probably the least common:
3: Uses less energy but produces the same results; e.g. a lightly loaded induction motor might save a few percent of loss associated with the magnetising current

For anybody seriously hooked on tungsten lighting, the VO will help save your lamp life if your mains is prone to going very high, but it won't usefully save you energy. It is cheaper to run less lamps at rated voltage than more lamps at reduced voltage, because the lamp manufacturers have already carefully optimised the tradeoff between life and efficiency at the rated voltage.

 

[Aaron b]

I have just been researching this myself after coming across a matt:e one today. Bigclive has done a video on them

It looks like they are sold with pv systems but I can't see how they would work for feeding in as they are not simple transformers and use a boost/buck set up. With general operation it sounds like if your mains voltage is high the inverter may not be able to produce a higher enough voltage within specification and the inverter could shut down, the voltage optimisers might help in this rare scenario.

 

[Ronron]

I have one installed without it I had 258v come through the sockets and with it I get 220v, I've had it since 2015 I've had no problems with it at all.

 

[Aaron b]

I have one installed without it I had 258v come through the sockets and with it I get 220v, I've had it since 2015 I've had no problems with it at all.

How was this measured though? I wouldn't trust simple meters as the sine wave is often distorted by harmonics and the rms calculation might be inaccurate because of it, I assumed if it was out of tolerance ukpn would sort it. Do you have solar and was the voltage causing an issue?