Global warming "biggest scam ever" says weather channel founder

[Rosuav]

Originally posted by Aristotle
That's interesting. I don't know much about LEDs when used as a light source. I have had one on my keychain for years, and it is useful for emergency lighting as well as for keeping young children entertained. I'd be interested to know more about their environmental impact and energy consumption compared to incandescent and compact fluourescent light bulbs.

LEDs are small. That's why they consume so little power. This means that they can be used:

• For signalling/notification - I think that's what they were developed for, and it's a realm almost completely dominated by LEDs
• Like your keychain, for emergency lighting - one white-bright LED in a completely dark room is a surprisingly potent light source
• In huge packs. Get enough small lights together and it makes a big light.

I'd never seen LEDs in a home light-bulb style of arrangement until I saw Mythbusters examine the question of whether it's better to leave the light on or turn it off. Among the lights they tested was one that was basically a cylinder with LEDs all around it. Unfortunately I can't find a picture of that sort of bulb, but Wikipedia has some photos of directional LED lamps: http://en.wikipedia.org/wiki/LED_lamp

The main downside to LEDs is their cost. Fine for small applications, they get prohibitively expensive when you need serious wattage. However, since they last for years and use very little electricity, they may be of value long term; also, the reduced heat output makes them more attractive in environments that need that. (Server farm illumination, anybody?) The classic incandescent and fluorescent globes are also quite fragile compared to LEDs, although the light globe shaped fluros are a lot more sturdy than the ten foot tubes.

According to that wiki article, LEDs have a problem with color purity. I haven't noticed it myself, but then, I only use them for generic illumination where precise color is immaterial; theatrical work, where the show depends on being able to light it with the right colour, is doubtless going to stay with halogen for many years. In most places, though, I'd say the main barrier to LED takeover is the initial cost (both of producing them and of rerigging their surroundings to handle the more directed/focussed light). I'd love to see LEDs become more prevalent... after all, they're geeky!!

Edit: At the bottom of that article is a fascinating comment. Pity it lacks citation... "Every 18 months the luminous intensity of LED lamps doubles." I want to check that out and find out precisely how Moore's applies here. If that's true, then that would put LEDs alongside other computing devices in that if you're not happy with it, wait a while and you can be confident it'll improve..