Alioth's Journal: The future of lighting...almost here?

I've now made 3 Luxeon Rebel based lighting modules to play around with (each with a PCB with the current regulating supply and two LEDs, ridiculously over-heatsinked with old heatsinks off Pentium 66 processors - well, they were free!). Here's a pic of the modules I made:

The naked LEDs on the PCB:
http://www.alioth.net/tmp/rebel-naked.jpg

And with the lenses:
http://www.alioth.net/tmp/rebel.jpg

In use, the PCB won't be seen, it'll be the other side of the roof of the boat it's going in (there will be holes drilled in the ceiling where the lenses poke through, kind of like how halogen downlighters are usually fitted in a ceiling).

I've been using the three modules to light my computer room for the last couple of days, they've just been sitting on my table shining upwards at the ceiling.

Each module uses about 3 watts, and the three of them together provide a similar amount of light as the 9 watt compact florescent that I normally use.

I do like the quality of the light. The LEDs I'm using are the most efficient type of Rebel (since in the intended application, efficiency is king). Even last year, the white Luxeons you could get weren't actually white - they were pale violet (my bike headlight is this kind of LED). Also, for a couple of years it's been possible to buy GU10 style downlighter LED modules. These again are pale violet rather than true white. They claim to be equivalent to 25W halogen, but having tried them, I'd say they are at most equivalent to 5 watt halogen - the claims on the box are grossly overstated (the GU10 LED units are very narrow beam. Perhaps it's the equivalent of a 25W halogen if you're right in the beam, but that's it).

But the latest Luxeon Rebel LEDs are actually getting there. They are bright enough and the quality of the light is good enough that I could make some home light fittings that use them with the wide angle diffuser/lenses that I'm using for the boat. What holds them back from general usage, though, is the expense of acquisition. Each of those tiny LEDs in small quantities costs the equivalent of about US$7, and you need 9 of them to get about the same level of lighting as a 9W compact florescent. They do, however, last 50,000 hours - if you were using them for 6 hours a day, they would last 22 years!

In conclusion, LEDs have got good enough now for specialist lighting - the whiteness is now good, and the efficiency is good (for instance, the roof space of my Dad's boat is far too constrained for a compact florescent downlighter, and halogens run too hot and are not efficient enough - so these LEDs fill that niche well). However, they still are too expensive for general home lighting. But in five years? The story may well be different.