LED lamps were unthinkable until the technology cleared a major hurdle just a dozen years ago. Since then, LEDs have evolved quickly and are being adapted for many uses, including pool illumination and reading lights, as evidenced at the Lightfair trade show here this week.
More widespread use could lead to big energy savings and a minor revolution in the way we think about lighting.
LEDs have been around since the 60s, but have mostly been relegated to showing the time in an alarm clock or the battery level of a video camera.
They haven't been used as sources of illumination because they, for a long time, could not produce white light â€” only red, green and yellow. Nichia Chemical of Japan changed that in 1993 when it started producing blue LEDs, which combined with red and green produce white light, opening up a whole new field for the technology.
Interesting, Chris. That is why we have bought houses to rent out (in British, to let). Hard part is to find houses with a high rent/cost ratio. If the rent is too much, people may as well make loan payments! If you want good renters, keep the house nice and the rent reasonable. Occupancy is the thing.
Neil commented "Silicon Valley is too expensive a place for ordinary people to live in anyway, so pollution there may be tolerable"
Hey it's interesting you say that. I stayed there with a friend in Feb this year & his house value (new house) was just a little more than we would pay anywhere in Australia; I just assumed that this was the same accross the USA. Then I was amazed to find how cheap houses were elswhere in the US - you guys don't just know how good you have it! In most areas we coudn't get a small plot of land for what you would pay for a really nice house, and wages would be similar. I think buying a house in the US might be a good investment.
On the LED, the 'white' colour is a very 'blue-white' and there are definite limits to brightness. They are great for signs but to illuminate things quite lacking still despite the significant advances. Not nearly good enough to eg light a room with.
Jim, they've actually got LED "bulbs" with that power--it's just a LOT of LEDs. I can personally see a use for them in flashlights and in hard-to-get-at places, say the turn lights on a car.
I've got a couple of concerns with them, though. First of all, the silicon/semiconductor processing used to make LEDs produces a lot of pollution; the #1 Superfund area in the U.S. is Silicon Valley. Second, if compact flourescents (CF) are any indication, LEDs will be well oversold.
I've got a bunch of CF bulbs in my house, and the chief complaint I've got is that they routinely overstate the power output by a factor of about two. Still good for many purposes, but not in general where you need enough light to read.
I haven't seen any of these white LEDs. I wonder how much light they put out? The analogies between LEDs and CPUs, however, I don't think will hold up. I haven't seen any LEDs that have the equivalent output of even a 60 watt light bulb.