[AT] LED flashlights

[Henry Miller]

On Thursday 22 December 2005 11:56 pm, DAVIESW739 at aol.com wrote:
> You will start seeing these on cars in the near  future I think all cars
> have to have led lights by 2009 and then comes the house  lights next. in a
> few years we can save millions on electricity just by changing  over to LED
> lights.

No we will not.   A LED lightbulb is about the same efficiency as a 100 watt 
lightbulb.    The advantage of LEDs is they last a long time (but so do 
fluorescent which are much more efficient), they retain that efficiency (such 
as it is) down to low power levels, and they have a more focused beam.   
These are all exactly what you want in a flashlight.   

They are not useful in normal house lights.   You will see them in specialized 
applications where the above is an advantage, but not for general house 
lighting until/unless the technology improves.

Compact fluorescent a much more efficient, and we would save millions on 
electricity if people switched to them.    People do not like the color of 
these bulbs, but LEDs use the same technology to get white light, so they 
won't like the color of LEDs either.

Studies comparing LEDs to standard light bulbs need to be done carefully.   
Many don't account for the fact that LEDs put light in one direction while 
the bulb puts it in all directions.   So more light lands on their collector 
per watt input, but only because the other bulbs are spilling a lot of light 
to areas other than their collector.