How much to run LED lights?

[dllive]

Hi,
I want to run some fairy lights in parts of the house that doesnt get daylight (stairwells etc...). I want these to be on 24/7.
Are these cheap to run? Do all led light expend the same amount of energy - its just the amount of bulbs that dictate how much electricity they use? How can I work out how much these bulbs will cost to run?
Thanks

 

[Taylortwocities]

Its the power consumed you need, not what light is given out.

The lighting set will state the consumed power, usually in watts.

Your electricity bill wil tell you how much your electriciaty costs you - this is stated in kilowatt hours. (KWh)

So if your charge is, say 12p per KWh and your light set is 10watts then it wiould cost you 12p to run those lights for 100 hours.

Capiche?

 

[Steve]

Hi,
I want to run some fairy lights in parts of the house that doesnt get daylight (stairwells etc...). I want these to be on 24/7.

Just because LEDs are cheap to run, theres no need to get carried away!

 

[flameport]

Something else to consider is that these 'fairy lights' will almost certainly NOT have been designed to be used 24/7, and so will probably fail fairly quickly.

 

[big-all]

i have several off these the output is around the equivalent off a 60w bulb
24-7-365 at 12p unit will cost 52 units a year or £6.25 compared to £62 for a 60w "normal or a £16 for a 16w low energy bulb
http://www.ebay.co.uk/itm/High-Powe...22?pt=UK_Light_Bulbs&var=&hash=item84b849a3f4

 

[dllive]

Thanks.

big-all: That bulb looks good.

Steve: I dont know how else to solve the issue. I've bought two motion sensor lights - but they behave unpredictably and I find myself having to pause at the top of the stairs and 'waggle my foot' to try and get the light to sense movement (Ive tried repositioning the sensor for better performance).

I know LEDs dont produce much heat, so if I do go for the 24/7/365 option - its not going to be a fire hazard is it? (Ill obviously turn these off when I go on holiday etc...)

 

[big-all]

the ones i have linked to are machined from solid aluminium they do give out heat but this is dissipated through the metal body
any danger is normally from the electronics failing and causing a fire this is a very small risk but all most nil chance on these bulbs because the electronics are fully within a solid metal tube 40mm across formed along the center off the bulb
besides that the heat generated is more likely to give discomfort like hot bath water no where near enough to start a fire that would have to be 3 or 4 times hotter

 

[bernardgreen]

any danger is normally from the electronics failing and causing a fire this is a very small risk

The hazard is that the electronics overheat and the heat damages the insulation on the mains cable supplying the lamp to the extent that a short ciruit through charred insulation occurs outside the lamp. This has the potential to continuously disipate over a kilowatt without the 6 amp MCB opening. Or many kilowatts for a short period until the MCB does operate.

To be 99% safe the wiring to the holder of any lamp that has the ability to produce heat in the cap in a fault condistion should be in heat resistant cable or have the cores individually sheathed in heat resistant sleeving.

 

[JohnW2]

Hopefully of interest: I've done an article looking at what the savings would be on typical 3 bed semi if you changed all lights to LED, what it would cost and how quickly you'd get your money back. In short you'd need to spend in the region of £750 and would save about £300 a year - so 2.5 years to get your money back. Full details here ******************
V

Interesting, but I wonder how generally applicable your figures are. Your cost saving of £300 per year is based on a 'pre-change' lighting consumption of 3,433 kWh per year - but that figure is about 81% of the DECC's figure (4,277 kWh) for the average UK household total electricity consumption in 2012. I therefore wonder how generally applicable your 3.433 kWh figure really is?

Kind Regards, John

 

[JohnCattell]

Hello John, Thanks for your interest in my post. As I make clear in the article this is a mocked up scenario which, as you can see in my tables, is worked back from the lamp type and burning hours. Both of which I'm quite happy to accept may not be as typical as I may imagine. The point is, it's all there for anyone to adjust or amend and I hope compare with their own domestic situation (which will be unique) and make a judgement on the benefits. Try doing the exercise yourself on a single room in your home and let me know how it turns out.

All the best.

John.

 

[JohnW2]

Hello John, Thanks for your interest in my post. As I make clear in the article this is a mocked up scenario which, as you can see in my tables, is worked back from the lamp type and burning hours. Both of which I'm quite happy to accept may not be as typical as I may imagine. The point is, it's all there for anyone to adjust or amend and I hope compare with their own domestic situation (which will be unique) and make a judgement on the benefits.

Yes, I understand all that. I was just suggesting/asking whether your 'mocked up scenario' was anything like realistic, since it appeared to result in an estimate of energy consumed by lighting which was over 80% of what is apparently the 'average total electricity consumption" of households in the UK. I would personally have guessed that the percentage would (even in the 'all-incandescent-lamp days) have been far lower than that, wouldn't you?

As you say, anyone can do the sums for themselves - but your figures may be so 'atypical' that very few people could hope to achieve anything like the £300 per year saving that your figures indicate.

n other words

 

[JohnCattell]

Hi again John, I fully appreciate what you're saying but, if you read the post can you see anything wrong with my method and assumptions? I do go into some detail about the occupants, ages of the children etc. and the way the rooms are used. I'm very happy for you to make a claim that this particular dwelling may be statistically anomalous, which I think is what you're getting at?The idea of the article is to give a consumer some sort of frame work to estimate for themselves how they could benefit (or otherwise) from investing in LED. As you can see I have provided a downloadable spread sheet so the householder can conduct their own audit, which I hope people will do.

All the best.

John.

 

[JohnW2]

Hi again John, I fully appreciate what you're saying but, if you read the post can you see anything wrong with my method and assumptions? I do go into some detail about the occupants, ages of the children etc. and the way the rooms are used.

I haven't looked in detail at your assumptions, but I will.

I'm very happy for you to make a claim that this particular dwelling may be statistically anomalous, which I think is what you're getting at?

What appears 'anomolous' is the discepancy between the assumptions used by your 'mock up' and the available official figures. The DECC report indicates that, in 2012, lighting amounted for around (from graphs) 17% of total domestic electricity - which, using their average total electricity figure of 4,227 kWh per household per year, amounts to some 700 kWh per year. That is dramatically less than your estimated figure of 3,433 kWh, and would have the effect of reducing your suggested saving of £300 per year to around £60 per year, and hence increasing the time taken to recover a £750 initial outlay from 2.5 years to over 12 years.

I see that your original post has been removed, and the link to your article obliterated. I suspect that must mean that someone 'on high' thinks that you are advertising something!

Kind Regards, John

 

[JohnCattell]

John, Please read the post, look at my website I'm not trying to mislead, misrepresent, con anyone or sell anything. If you run a 50w lightbulb for 8 hours you use 0.4 of a kwh if you run 6w lightbulb for the same time you use .048. That is the basis of the article. I'm trying to help people work this out for THEIR specific circumstances by giving a detailed example of how I've done it. No smoke and mirrors it's all there tabulated on the site. I even provide a spread sheet for folk to do the same. If you can find anything wrong with post I'll be very happy to correct it and give you my sincerest apologies. All the best to you. John.

 

[JohnW2]

John, Please read the post, look at my website I'm not trying to mislead, misrepresent, con anyone or sell anything. If you run a 50w lightbulb for 8 hours you use 0.4 of a kwh if you run 6w lightbulb for the same time you use .048. That is the basis of the article.

I have no argument with your calculations - which, as you say, are simple and (in terms of the figures they're being applied to) correct. It is you assumption about 'usage' which I think is probably very atypical.

I've only really got as far as the first couple of lines of your hypothetical scenario, but I think that's enough to illustrate my point. You indicate a total of 780W of lighting, on for an average of about 6.25 hours per day, to light the kitchen/diner. That amount of energy is almost enough to do the cooking, let alone the lighting, and the total of 1,778kWh per year is, for that one room, some 2.5 times greater than the DECC's figure for the total lighting energy of an entire household.

I would suggest that the 780W of lighting for one room is very atypical (or, at least, 'ridiculous' - even though I don't doubt that some people do it!), and even that your average of 6.25 hours per day is probably appreciably OTT (given that little lighting is probably used in a kitchen/diner during summer months, and quite probably not even 6 hours in winter).

I realise that individuals can do the calculations for their own situation, using the methods you have described. I suppose all I'm really saying is that, if they are interested, they should do that - since if they pay any attention to your (seemingly very atypical) hypothetical example, they could unecessarily get their hopes up

Kind Regards, John