All Torque

As part of some government energy funding the want to fit one of these devices in my property, are they reliable and for instance if my domestic appliances are not getting the correct voltage will they get up to heat sufficient i:e will my kettle boil, will my washing machine heat my water as efficiently as it does using standard 240v as opposed to the 220v these optermizers work at.
In other words is it worth having it fitted .

alcazar

iTrader: (2)

Standard UK voltage is, and has been for some time, 230V. It was standardised across Europe, some years ago.

I can't see the point in such a device for lowering your voltage by 4.3%...what's it supposed to achieve?

Except that Power = Volts x Amps, so if you lower the voltage, you've lowered the power, thus used less by 4.3%?

But everything will take 4.3% longer....so what have you gained?

AndyC_772

iTrader: (2)

Never heard of these devices, are they just a 240V:220V transformer?

It does beg the question, why? Anything with a switched mode power supply (that's just about any electronic device - TV, computer and so on) will draw more current to compensate for the lower voltage, and the total power will be about the same.

Filament bulbs will be a bit dimmer, and draw a bit less power (unless you fit a higher wattage bulb to compensate). If you have an electric shower then you'll get a slightly reduced flow rate and save a bit of energy.

The kettle will take longer to boil, but will actually use a bit more energy in total because it's losing heat for a longer period of time. Anything with a thermostat will draw less current but the heating element will stay on longer, so total energy remains about the same as before.

A transformer, of course (assuming that's what it is) is not perfect, though, so even if you don't mind putting up with dimmer bulbs to save a bit of power, you might simply be losing it as heat in the transformer. I have a 1000VA transformer at work which dissipates about 50W just by being plugged in.

I think more information is needed, because the idea of sticking a whole house on a nearly 1:1 step down transformer is so flawed that I can't believe anyone would seriously suggest it as an energy saving measure. Could they?

alcazar

iTrader: (2)

It seems more than odd...it sounds like snake oil.........

What's it going to cost?

I recently had someone try and sell me something that would "keep my solar electric panels running at night......"

tarmac terror

iTrader: (2)

Had a thing like this installed in work called 'power perfector' - it is being deinstalled on 24th March!!!!!

Cockney Wideboy

iTrader: (2)

what, power a load of sun lamps from the grid

Storing unused energy from during the day to use at night would be worth while...I.e a big battery or capacitor...

dunx

iTrader: (3)

That sounds suspiciously close to "power factor correction"....

Google will enlighten you.

Used in industry for inductive/capacitive loading, not really a domestic item, IMHO.

dunx

Saxo Boy

VO is a legitimate technology and works. Typical payback is around 5-7 years depending on the energy profile of the devices in your home.

The first thing you have to understand is that while the UK moved in (1996 iirc) to 230V the reality is that we made zero effort to change our infrastructure. Instead, we got Europe to agree to a tolerance that allows the voltage to range anywhere between 216V and 252V. The UK average remains 242V and houses that are closest in the curcuit to the local transformer can often be in the high 240s. I check the voltage in my own home regularly and it's nearly always over 242V.

A VO unit is essentially a little step down transformer with some circuitry to control when in the sine wave it switches in and out of circuit. Typically, it'll tap the voltage down by 18V and will sit in bypass below 236V. Thus, if your incoming supply is 242 volts the VO unit will drop it to 224V. If it's 236V it'll drop it to 218V.

Most EU appliances work best between 220-230V. Certain (usually older) appliances draw less power when fed a lower voltage - hence the energy saving. Furthermore, by operating in their optimal range, they are less stressed and last longer too. As someone rightly pointed out however, any device with a feedback loop (i.e. a thermal feedback) will show no saving. In the case of the kettle, you will still need the same energy to boil the water to 100 degrees so a VO equipped house will simply take longer. Where you will make savings is on traditional bulbs, electric showers and compressor motors in fridges, etc.

Yes, your bulbs will be fractionally dimmer and your shower a baw hair colder. However, what you must realise is that supplying your 9kW shower with the correct voltage means it will be drawing the correct power (9kW). The reason it will be colder (assuming you can even tell) is because for the past 'x' years it has been over-volted and running at 9.2kW (guestimate).

Domestically VO will probably never really take off. The issue is that all appliances are being made more energy efficient and are designed to draw the same power at any voltage within their operating range. You make no saving with LED bulbs, or computers, laptops, etc.

Adrian F

Tarmac Terror why are you having the power perfector removed?

at my place our energy conservation expert is getting one installed says we should save tens of thousands per year supplying a office block for 1400 desks

ALi-B

iTrader: (1)

This.

Last time I had teh voltemter on a mains socket at home it read a few volts over 240, dropping a few volts when I turned on some appliances (kettle, oven etc).

The electrics at my grans flat peaked at 260v on the same multimeter!! Its since been rectified after I complained to National grid about exploding GU10 bulbs at the rate of 1 every week and frying dimmer switches.

Conversely our works office is about 230v and dropping to 210ishv under load which is probably why our flourescent tubes play up (old fashioned ballasts). The place need re-wiring, landlord refuses to pay to get it sorted. :rolleyes

Leslie

I always thought that standard UK mains voltage is 240 volts within a fairly close percentage anyway. My mains voltage measures at exactly 240 volts.

Les

AndyC_772

iTrader: (2)

Saxo Boy is right, it's "230V" across Europe these days, all in the name of standardisation, but with a wider tolerance to accommodate the fact that the UK and mainland Europe are still just as different as they've always been. I just measured the mains voltage near the consumer unit in my garage and it's 243.6V.

As to whether 230 or 240 is "optimal", I'd argue it's a pointless debate. If you want to save a tiny amount of energy by having a tiny amount less hot water coming out of your shower and having slightly dimmer filament bulbs, then go right ahead. One option is not "right" and the other "wrong", unless perhaps you live in a world where ratings and tick boxes are more important than basic physics.

I'd still love to know just how efficient these transformers are, and how much of the apparent saving they waste as heat. For those devices (bulbs, heaters) which do actually draw less power, they'll draw about 84% of the energy at 220V than they do at 240V (power is proportional to voltage squared), plus losses in the transformer. Every other device, including any heaters which are thermostatically controlled, will draw the same as before, plus their losses in the transformer.

Unless the transformer is extremely efficient - at least 95%+ - I'd be amazed if such a device saves any power at all, much less pays for itself.

I smell an idea which, though well-intentioned and probably saleable, doesn't stand up to scrutiny.

alcazar

iTrader: (2)

Me too.

I questioned the guy about making my solar panels work during the night, asked if it was a battery, or huge capacitor, he got very defensive.

All Torque

The guy who wants to fit it seems as though I MUST have it done, i:e I opted in and not that I can opt out, he must be getting a good price to fit it is all I can think. I had a leaflet through the door saying that they intend to fit it I`ve not signed or said I will have it done to anyone.

tarmac terror

iTrader: (2)

Don't know the exact detail as estate management isn't my bag. This thing came with much hype (power savings, stabilised voltages and prolonged equipment life being some of the claims I remember), I assume it didn't live up to the hype.

Saxo Boy

What do you mean by this? Do you mean you wanted batteries to store the energy during the day for use at night? If so, that's nowhere near economically viable.

Your best bet is to use that energy effectively during the day. Raise the ambient temperature of your house during the day with oil filled electric radiators thus reducing the load on your central heating system. If you have an electric water system keep your water nice and hot during the day, etc.

alcazar

iTrader: (2)

No, mate: he came on to me asking if I was interested in buying this gizmo that would make my panels generate all day.

I questioned him, but he got very defensive.