Jay (and others of a technical bent)...

Here is a page showing the relative efficiencies of the various forms of
light emitters:

http://members.misty.com/don/lfunfact.html#lw

Note that amongst the "normal" forms of lighting that you can buy over the
counter, the most efficient is the small 1" diameter 32 watt fluorescent in
a 4' tube (F32T8) at about 90 lumens/watt. The best LEDs as of the date
this was written is about 70 lumens/watt.

Dean is proposing an LED (or string of them) that puts out 67 lumens/watt,
but as the page says, this does not include any ballast losses. White LEDs
have a forward voltage drop of about 3 volts/lamp, so to get decent
efficiency you string 4 of them in series to get CLOSE to 12 volts, but you
still wind up fudging around with ballast resistors and/or switching current
regulators to keep the power to the devices constant. And, they are going
to get hotter than billy blue blazes unless you keep airflow over them.

The LED is probably going to be the "light bulb" of the future (see
http://www.superbrightleds.com/ for a smattering of what is on the market)
and notice way down at the bottom of the "LEDS" page that there are some one
watt devices on the market with integral heat sinks. These suckers are
BRIGHT and expensive, but as with all mass marketed devices, once the auto
industry picks up on them, they become dirt cheap.

And, on Don's page (again) you find that a 60 watt incandescent light bulb
puts out about 600 lumens, or a lousy 10 lumens/watt. The sooner we abandon
Edison's invention the better.

Jim



--
"Life is not a journey to the grave with the intention of arriving safely in
a pretty and well preserved body, but rather to skid in broadside,
thoroughly used up, totally worn out, with chocolate in one hand and wine in
the other, loudly proclaiming 'WOO HOO What a Ride!'"
--Unknown
wrote in message
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Jay,

How much would you be willing to pay for an LED light bulb that put
out 800 lumens on 12 Watts of power? (yes, I am considering making
such a beast)

Dean