Period electicity voltage

[skier-hughes]

A friend of mine is considering having solar pv fitted.
I'm very pleased with mine, so said she should seriously consider it.
he chap who came to quote gave her a whole list of things they like to fit as well, including thatch hatch, gas optimisation, led lights throughout the house and a voltage optimiser!
His piece of paper claims that optimising the voltage will prolong the life of electrical goods and reduce the electricity bill as there will be no waste electricity, as they charge for voltage supplied.

All sounds a bit dodgy to me, anyone know anything about this?
I'm off to do some googling and also am suggesting she have our electrician go round to quote and he can tell her more about this thing!

 

[Flyfisher]

I've heard about it but have never really looked into it seriously. The basic idea is to reduce the mains voltage so that connected devices consume less power. But. (There's always a but!).

For example, lower the voltage of a incandescent bulb and you'll certainly reduce power consumption but you'll also get less light, which you can do by fitting a lower-wattage bulb anyway!

Also, heating devices will take longer to heat things up. For example, boiling a kettle requires a certain amount of energy whether you have a 3kW heating element or a 1kW element. Use a lower power heater and it'll just take longer to boil = same amount of overall energy. That's just physics, plain and simple.

More complicated devices such as TVs and PCs generally have 'smart' internal power supplies these days which means they can operate from any mains voltage around the world. But they still need a certain amount of power to work correctly and it's the job of their internal power supply to sort it all out. They'll just draw whatever power they need regardless of the voltage. The lower the voltage, the more current they'll draw to compensate.

The above may not apply exactly in the case of certain devices such as electric motors but typical homes have few of those - usually just fridges and freezers - so I'd guess the potential savings there are pretty insignificant.

Having said all that, I tend to be naturally suspicious of these sort of 'wonder devices' so perhaps I'm not being fair. But, if it was such an easy way of reducing energy consumption why not simply lower the voltage from the generating stations instead of installing millions of special devices in every home and business? Perhaps that's why USA uses 110v ? :wink:

However, I'm certainly no expert so could easily be wrong, and I'd be interested to know if that's the case, so just treat these as rambling thoughts and questions to be asked.

Meanwhile, replacing all incandescent - and to a lesser extent - CFL lamps in favour of LED 'bulbs' will significantly reduce power consumption, albeit at an initial cost.

As an example, in our new kitchen extension we have 13 LED downlighters x 4.5 watts each = 58.5w or more or less a single standard incandescent lamp. They are supposed to be about 10x more efficient so that's the equivalent of about 600W of standard lighting - a pretty big saving!


Edit: I'm sure you'll have found this by now: http://en.wikipedia.org/wiki/Voltage_optimisation

But here's some stuff that discusses the effects of PV generation on the voltage at the consumer unit that I hadn't thought about, though the overall conclusion is still that any savings in a domestic environment are likely to be tiny: http://www.yougen.co.uk/blog-entry/1948/Is+domestic+voltage+optimisation+all+it%2727s+cracked+up+to+be%273F/

 

[Lime]

Voltage optimisation is described as snake oil by many who should know.
Links:-

http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=54572

http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=50486

http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=37304



Sometimes I repeat, sometimes they produce a saving in electricity consumption per se but usually at a cost or loss elsewhere.
For instance boiling a kettle at lower voltage consumes less watts but to reach boiling point takes longer so any saving made by the reduction is completely lost.
Similarly using an incandescent lamp at lower voltage uses less watts but the reduction in light output is large. It would be much cheaper to use a lower wattage lamp without any optimisation.
Nearly all modern equipment, like computers, phone chargers, CFC lamps and the like will work well on reduced voltage but that is because they will take more current as the voltage drops! Thus they use the same amount of power overall as before optimisation.

There are very few advantages to voltage optimisation and a great many disadvantages.
One disadvantage they often don't tell you about is that the voltage optimiser uses power to operate all the time.
Also many have a limited power capacity so if you use a lot of electricity it just automatically by-passes itself for its own protection (and yours!).

Technical~
For ordinary domestic premises you do not need to worry about power factor if you have an analogue (not "smart") domestic electric meter as it is unable to measure phase angle so you do not get charged for it.
The new "smart" meters are able to measure phase angle etc.
Whether the electricity companies will use that fact to increase their profits in the future remains to be seen.
Personally I think the new meters are of no benefit to consumers whatsoever.

.......................................Post altered to give information concerning "smart" meters.

 

[Flyfisher]

I loved this article's conclusion:

"The drawback of domestic voltage optimisers is that they are a waste of money."
http://www.telegraph.co.uk/property/propertyadvice/9153868/Jeff-Howells-DIY-advice-home-voltage-optimisers.html

:lol: :lol: :lol:

 

[noj]

http://www.which.co.uk/energy/energy-saving-products/guides/10-eco-products-you-dont-need/

Same conclusions here...

 

[skier-hughes]

Cheers all, just what I thought.

 

[wobs]

Ahe chap who came to quote gave her a whole list of things they like to fit as well, including thatch hatch, gas optimisation, led lights throughout the house and a voltage optimiser!
His piece of paper claims that optimising the voltage will prolong the life of electrical goods and reduce the electricity bill as there will be no waste electricity, as they charge for voltage supplied.

All sounds a bit dodgy to me, anyone know anything about this?

LEDs are currently only worth it if you use said light for many hours per day, owing to their high capital cost. CFLs are worth it elsewhere.

I did a spreadsheet to work out whether each bulb was worth replacing with LEDs. In most instances, if we were using a bulb for less than 4hrs per day every day, it wasn't worth it. And where usage was 4-5 hrs per day, you need to be very careful about the numbers. Where a lamp was used for over 8hrs in winter, I was able to get one for £13, but that was because it was an LED SMD, which are particularly efficient.

Another example is our security light which came with the house when we bought it. I believe it to be 500w, but because I only use it for about 1min per day, it isn't worth replacing.

We also have an uplighter, which I've persuaded Mrs Wobs to stop using, as its about 180w. A colleague at work has one that 240W, and uses it about 5hrs per day. I showed her how much it cost to run per year, and she was quite shocked (about £54/yr).

The only place to get LEDs from currently is the internet. I have yet to see a decent deal in any shop. And B&Q has some of the worst deals anywhere for them, as some don't just have terrible £/lm, but also bad w/lm rates. Two rates you should be aware of, as not all LEDs are made equal.

To replace a 75w bulb, you need to be looking at something like this:
http://www.amazon.co.uk/Lighting-Bright-Samsung-Incandescent-1080lm/dp/B008WHBDQI/ref=pd_sim_light_3
Which has recently come down in price. I paid more for these. I have four in recessed fittings in our kitchen, and I maybe should have got the 10w versions, but we have plenty of light in there now.

The LED SMDs I got for a lamp are here:
http://www.lightrabbit.co.uk/9-watt-b22-led-bulb-60x-smd-5050-80w-equivalent.html
Payback - quite a few years to be honest, but they are perform very well.

Make sure you get the right colour (warm white usually).

Basically, if its not worth it finanically, don't do it, as there is nothing altruistic about energy efficiency.

Also, not all LEDs are made equal, so check reviews and do your research.

 

[wobs]

An article about solar pv production:
http://asia.nikkei.com/Business/Trends/China-hands-death-sentence-to-75-of-solar-cell-makers
Prices may be going up for a while.

 

[LadyArowana]

http://www.lightrabbit.co.uk/9-watt-b22-led-bulb-60x-smd-5050-80w-equivalent.html
.

For anyone else that was very disappointed to follow the link and not find one of these

They can be found here http://www.pupsikstudio.com/white-rabbit-lamp-heico.html

 

[plasticpigeon]

Is a maximum power point tracker for a solar panel array standard equipment these days??