Low Energy Light Bulbs(CFLs)

The only issue with these is that some low-energy bulbs can interfere with RC5 IR transmission...

All I know is they ain't as bright.
Does that maths make sense to anyone other than RA?
Is he saying the 13 w CFT needs 2x the power per watt produced and therefore less efficient?
Or the saving is less than every one says?

Do they do one an equivalent CFT to 40w SES for cooker hoods?

I had a chat a few weeks ago about this with the guys at work. The electricity bill for our company has a power correction factor on it, and we are running somewhere around 0.94, IIRC. I don't think we pay any extra for that factor. This isn't mentioned on domestic bills, but the power companies will need to recover the cost somehow, so cost per unit may well rise.

Tony

quote:

Originally posted by BigH47:
All I know is they ain't as bright.
Does that maths make sense to anyone other than RA?
Is he saying the 13 w CFT needs 2x the power per watt produced and therefore less efficient?
Or the saving is less than every one says?

NB: the quoted power of a bulb is the power it uses rather than the power of the light it emits.

He's saying, at first, that twice as much power per Watt used needs to be generated for low energy bulbs as for incandescents.

Based on this it seems that since low energy bulbs use 1/4 of the power of "equivalent" incandescent bulbs, low energy bulbs still require the generation of only half as much power as incandescent bulbs.

However, this is not what RA says. He says, "My tests have shown that the CFLs USE [my capitals] half the power of a 60W lamp, not quarter as stated..." So RA seems to want to count the apparent power twice. Either that or he has failed to explain adequately the meaning of "apparent power".

He also seems to imply that the cumulative effect of the CFLs results in a separate increase in the power that must be generated.

He goes on to say that that the electricity system would need to double its output as a result. Perhaps I am mistaken but I suspect that light bulbs do not use the majority of Britain's electricity. If so, this suggests that RA is arguing that a 15W (60W equivalent) CFLs actually requires 240W (or more) to be generated - i.e. 180W (or more) more than a 60W incandescent.

Not that I have enough knowledge to have an opinion but it sounds a touch implausible to me...

I think it is all to do with electrical components that use induction.... I'll have to check again with the guys at work. We already use hundreds of flourescent tubes, so our correction factor is quite good.
I think that millions of households going from mainly incandescent to CFLs will have quite a large effect in the already power-hungry evenings.

As usual, Wikipedia explains it. I think!

Tony

I thought the main concern with these bulbs is yes they may last longer, but environmentally talking they have mercury in them making them very hazardous to dispose of.

The problem with CFLs is simply that the power factor is so dismal, owing to the way they all dirctly-rectify the mains input. This means that the peak current draw is two to five times what you'd calculate from the stated power consumption. Moreover, it is drawn in a very peaky, and therefore electrically noisy, way. If you 'average' this current draw sufficiently then yes, they are 2-3x more efficient on a lumens-per-watt basis

Domestic meters only measure 'real' (ie rressitive) power, so as a domestic consumer you don't get billed for the excess (reactive) current. However, a reactive load generates waste heat in the generation and transmission network just the same, so overall CFLs are barely 2x as efficient as as ol'fashoned glowplugs. Rod Elliot's excellent Elliott Sound Pages website has a page dissecting CFL pros and cons in great detail.


I'm all for efficiency, but not at this cost. Apart from that my main bugbears with CFls are 1) the absolutely horrible colour rendering the light gives, even the socalled 'daylight' balanced ones, and 2) the strange perception that the room gets darker at switch-on until the things warm up!

Well.

I still use standard incandescants.

My remotes work fine and to be honest I haven't noticed "massive" reduction on my lecky bill when I did use the low energy variety.

I remember PFC calcs at uni... those where the days!


PS:- The main problem I have, is having to ring up my electricity provider everytime I get a bill to re-calc my balance due to the ridiculous "estimate" they provide.

"thank you sir, your new balance is....(much less than we printed on your bill)"

Well, I don't know how well RA understands the use of a full spec power meter, nor do I know if he "double counted" the measurements.
I am not surprised that the CFL bulbs have a poor power factor though. The manufacturers could correct for this, as most good and modern switching power designs do. But it would add considerable cost over the current cost of the bulb.
I can't wait to see how the power companies will react (sorry, bad pun!) to this issue as the bulbs become more popular. Maybe they'll force consumers to provide active PFC (power factor correction) to their loads!
I have a number of these installed in various applications around my home but have not reaped the supposed benefits of their long life. Seems that they're always going out.
Where is the economy or positive environmental impact of regularly disposing of a relatively complex, complicated to manufacture and laden with new toxic chemicals bulb when the incandescent bulbs are at such a high state of refinement (i.e. cheap, easy to make, last a long time, low disposal load)?
Come, now, we all know that the main reason for these bulbs is to make the green consumer feel smug with THEIR contribution to a greener earth while their neighbor (or USA or China or ...) continue to crap up the earth.
David