Here's a follow-up question to the one I posted about halogen lamps. What about LED lights? Are they environmentally friendly and energy efficient? (Not for the kitchen but as desk or floor lamps.)
Thanks once again!
I've never used them, but just from what I've read, their efficiency is similar to that of fluorescents and they last even longer. The only downside to them at this point I'd think would be the price.
LED's at the moment are about on par with CFL's as far as light output per watt. Yes, they tend to be pricey . . . but that continues to come down as technology gets better. Right now you see them showing up in a variety of things: traffic lights are one . . . taillights on motor vehicles . . . there are even LED beacons such as on radio towers and such. As far as overall lighting; don't believe there's much out there and it would indeed be expensive.
If you think about the uses mentioned above; you'll notice that in ALL of them; the beam of light is in a narrow band . . . pointed in pretty much one direction . . . you don't care much what a stop light looks like from the side . . but front on it must be highly visible. My point is that they are pretty well suited to tasks which need light in one area or zone . . task lighting as opposed to general lighting. This too, will probably change with newer technology.
They can indeed enjoy a very high lifetime . . . it varies with how hard you drive them; ie brightness level. At reasonable drive levels they can achieve realistic lifetimes of 50,000 to 100,000 hours . . . . far in excess of CFL's or anything else. Many years ago ( 1995 ? ) I wrote an article for Home Power magazine ( alternative energy / conservation ) about an LED nightlight that had VERY low power consumption . . . I still have several of them today. Again; they do well where light levels required are not high; and they can be in a relatively narrow zone or area.
Don't hesistate to poke around for them and try them . . there is new stuff every day. I imagine over time that they will indeed become a signifigant source of light in uses now only being filled by incandescents and CFL's . . . .
Thanks for the info and insights! I found a "gooseneck" LED light (all metal with a 3" base and adjustable to 36") on the internet that can fit well with my "contemporary, Ikea-type" decoration. I don't think it is too costly ($85 for a nice reading / side table lamp in the living room). Of course pics on a website may look great, and actually seeing, using the item is another thing! But I will probably try this one out.
As a stop-gap measure, I installed a cable light, like people use for outdoor Christmas decorations, inside two closets. They work great! Very indirect lighting, soft, low-key. I was going to install switches but haven't gotten around to it.
Lighting in closets is very restricted under the electric code. Exposed bulbs are not allowed. Even an enclosed bulb has strict restrictions on location. There is to much flammable stuff in there, and no one watching behind the closed door. Christmas lights are not allowed under any circumstances.
The most common closet lights are recessed intothe ceiling with a glass lens. The light is technically not 'in' the closet at all.
Something also great about LEDs is that they produce virtually no wasted energy in the form of heat. They'd be great for closets, in fact.
I think Norm was talking about rope lights; there are in fact LED rope lights available, and I *think* they come in white. Only draw about 0.02A for an entire string, too.
The outfit linked below not only has LED rope lights, but LED bulbs as well (beyond that, I dunno anything about 'em):
Here is a link that might be useful: LED Lighting
LED lights can be misleading in some ways . . . .
As far as light output; they consume ( those presently widely available on the market ) about the same amount of energy to produce a given amount of light; as a high efficiency fluroescent. So, while you can hold one in your hand and feel "no" heat; they do indeed produce heat at about the same level as fluorescents do. We do not PERCEIVE the heat; simply because LED's tend to be very good at producing high intensity in a shaped beam . . . not light in all directions. This makes them very useful for small task lighting, or uses where the light is really only needed in a narrow beam. Large area illumination is NOT their forte; and while it can be done it DOES get expensive . . . and the energy consumed to do so will be on par with fluroescents doing the same task.
As a perfect example of what I'm saying; consider traffic lights, or now the tail lights on vehicles . . . . tradtionally done with incandescents. The LED equivalents that can be had do NOT produce the same amount of light . . . . but they DO produce a high level in the specific direction / plane that it is needed in. Traffic lights need to be very visible directly head on . . . their illumination to the sides drops off rapidly . . . LED's can serve this function and other similar ones very well . . .
One more note . . .. "Luxeons" . . . are a particular LED that have VERY high light output . . . and they come manufactured ON a heat sink; which in turn must be mounted to a real heatsink to keep temps down where they should be. The particular circumstances of the application will determine how much of a heatsink is needed.
Also know that LED's are for the most part quite tolerant of running them at higher currents / temps than they are spec'd at . . . while not a good long-term idea; it can produce amazing amounts of light . .. at the expense of LED lifetime. Heat is one of the major killers of LED's; over time their output will drop . . . and running them hot will accelerate WHEN that will happen. It may matter in your application; or it may not. Their lifetime is VERY long; so using one in a way that drops it's useable lifetime to half it's normal one; simply will not matter in some circumstances. If the LED in your flashlight lasts only 10 years instead of 20; it just may not really matter . . . .
Our city has replaced standard bulbs with LEDs in all of the traffic lights. Unfortunately, many of our city traffic lights hang overhead on a single steel cable. When the wind blows strong, the lights tilt and the LEDs become hard to see when approaching straight on. I forsee a traffic accident caused by this in the future.
This should put the efficiancy of LED's in perspective. When my son turned five back in August, I got him an LED flashlight. We still have the same batteries and it is doing fine. The previous incandescant record was about a week.