by MarkR » Fri 03 Sep 2004, 06:10:13
$this->bbcode_second_pass_quote('', 'C')an anyone comment on the current state of the art of LED lighting? Has it reached the point where it's economically reasonable and functionally acceptable?
Current LED lighting's main selling points are size and long life. Efficiency is also important for coloured light sources.
I've got some state of the art LEDs sitting on my desk at the moment (
Luxeon III), which I've been experimenting with.
They are very expensive (I paid about $US 15 each, although in bulk they go for about $8-10 for a 3W LED). For the white ones the efficiency is about the same as good quality tungsten or average quality halogen. You will therefore gain little by using them in domestic lighting, and replacing fluorescents may well be a backward step. Colour quality of the white LEDs is improving, especially with the new 'warm white' varieties - however, they still have the slightly odd colour rendition of fluorescents.
However, where coloured light is required, coloured LEDs are hugely more efficient than white lights with coloured filters. E.g there are significant energy savings in replacing lamps in traffic signals with LEDs.
However because the LEDs are very small (mine are a bit smaller than the nail on my pinky) then can be used for very precise illumination - so avoiding wasting light by directing light away from where it is not necessary.
In short, they're not a realistic replacement for bulk lighting at present. However, for certain applications like signage or task lighting there may be genuine advantages. Their unique electronic controllability also means that they are increasingly used in stage lighting (think lamps that can change to any colour at any brightness instantaneously under computer control) however the price is positively terrifying.