[Chat] Article on LED lighting

[Stephen J Gewirtz]

Here is an article in today's NY Times: 
http://www.nytimes.com/2013/01/22/business/leds-emerge-as-a-popular-green-lighting.html?hp

The key point is that LED lighting (not the same as CFL lighting) is 
very energy efficient.  My own feeling is that I should wait a bit more 
(and use up my old spare CFL bulbs), but by the end of  next year, I 
hope to switch entirely to LEDs.  Right now, a bulb will cost $10 to $15 
or maybe a bit more, but it should last 10 years. In the long run, you 
will save enough on electricity to pay for the extra cost of the bulbs.  
According to the article, by some time in 2014, more LEDs will be sold 
than incandescent  bulbs.  But that may be because the old fashioned 
incandescent bulbs are becoming illegal to sell.  There will be more 
energy efficient halogen bulbs which I think are a form of incandescent, 
but they can get very hot and may present a fire hazard.  There probably 
will be other incandescent bulbs which meet the new energy efficiency 
standards and do not get as hot as halogen bulbs.

Note that LED bulbs should drop substantially in price over the next 
year or so as more are sold.  Also, some lamps and lighting fixtures 
specify a maximum wattage incandescent bulb to use (because the bulbs 
put out heat), but it is safe to use an LED or CFL bulb that puts out a 
higher amount of light since it will generate less heat (and also will 
have a much lower wattage).  I note that an LED that puts out the amount 
of light of a 60 watt incandescent bulb uses about 10 watts of power.

As I looked at LED bulbs on the Home Depot web site, I noticed that they 
specify color temperature.  The hotter the color temperature, the colder 
(more blue) is the lighting (yes, higher color temperature equals colder 
lighting).  Many bulbs were 2700K or 3000K (K stands for Kelvin, which 
is the Celsius temperature plus 273.1), which should approximate the 
color of the old incandescent bulbs.  A higher color temperature will 
approximate the color of daylight. You can google "color temperature" to 
get an idea of what it all means.

According to the article, one can find bulbs where one can vary the 
color, but such bulbs cost about $200 for 3 bulbs and the control of the 
bulbs.  Personally, I just want plain LED bulbs that replace the 
incandescent ones and have about the same color temperature.

Steve