mains LED buls (GU10) revisited

[jonathan.ives]

Sorry to start a new thread on old territory, but I wondered if anyone has any newer experiences of this technology. 18 months ago I tried a couple of bayonet & GU10 replacement bulbs utilising LED technology. While they work the light levels are very low and harsh in quality. So the white , even the 'warm' white, appears to be closer to the UV end of the spectrum, not unlike a flourescent tube.

I really want this technology to work as I have a large number of GU10 lamps in my house which use too much electricty and seem to need continuous replacement. My hope is that, like the early low energy bulbs which were niether bright enough or warm in colour, LED technology will improve.

These bulbs are not cheap. I have seen some newer types quoted as using multiple 1w LED's with 'warm' light spectrum and 30K hours for =A320 a go. If they work and the light is good, it may well be worth considering, but I wondered if anyone has any recent experiences of this evolving technology.

many thanks

Jonathan Ives

[Ian Stirling]

'Warm' white LEDs can be very good. But. I would be very, very surprised if, at this price point, decent LED lights (same output as filliment) were available before 5 years. Still surprised at 8 years.

Several problems. Existing 'warm white' lights get maybe a little better efficiency as halogens. This wouldn't be so bad, but they only do it at 25C or so. Enclosed fixtures mean they get much hotter, and the efficiency crashes once you get more than 1 or 2W of LED in there. If you are putting them in for low maintainance, and power use, knowing that they only put out under 10% of the light, then you may be satisfied.

If you're looking for performance similar to fluorescants, then it's going to be even longer.

There are 'drop in' fluorescant solutions, that admittedly are not perfect, but are probably better than LEDs you'll get this decade.

Adding fluorescant uplighters may also be a solution.

[Andrew Gabriel]

Agreed.

I think LEDs for general lighting is a non-starter unless/until there's some really significant breakthrough, of which there's been no sign for years in spite of many people looking. The current rate of incremental improvements just doesn't get close in any reasonable timescale. In reality, at prices which are viable for consumer products, they've only now reached the efficiency of filament lamps. We've had lighting systems many times more efficient than filament lamps for over 70 years.

They will find specialist areas where they can compete. If you want a coloured lamp and there's a suitable LED available, this is much more efficient than using a white light source and filtering out the parts of the spectrum you don't want. If you want a very narrow beam with little power, they can be made to do this much more easily than constructing optics around a larger light source to produce a concentrated beam. You'll probably see them appearing in more effects lighting too. However, lighting your living room -- forget it. I'm sure we'll see some more breakthroughs in the future in general lighting, but I doubt they'll involve LEDs.

[Guy King]

The message from [e-mail] (Andrew Gabriel) contains these words:

Another specialist area which may become more common eventually is the ease of producing large areas of diffuse light. Much easier with LEDs.

[jonathan.ives]

Well thansk to all for the comments about LED-based GU10 alternatives. In the end I puchased one of the 11watt Low energy GU10's (Megaman brand). I have to say that this shows more promise. The light is diffuse, and still a bit cold compared to the slight yellow quality of halogens, but I will be swapping in more and more of these over time. My wife commented that the 11 watt was actually a bit too bright, so I think that shows how good these are