i disagree - LED's as light sources have an advantage over most other light sources that you seems to be ignoring - a very fast response time.
All you need to do to get efficiency out of them is hook 'em up to a little inverter - supplying brief pulses of current with a very low duty cycle at about 10 kHz or so - the light will seem perfectly bright and usable, as the response time for even a white LED to go from off to 100% is nothing compared to the time it takes a human retina to notice that the light is already off.
Obviously, this is going to save power - the average power usage would be tiny, the intensity of a pulse would not.
You just can't do that with a incandescent bulb.
The better LED torches already do this - they practically SIP current from a battery, and a penlight sized torch using a single white LED is enough to read by in an otherwise unlit room - left in one place pointing at the ceiling!
Plus it lets you get away with another neat trick too - running the LED at a higher peak current then it is rated for, so long as the pulses from the inverter are suitably short, and the average power doesn't exceed the LED's power dissipation rating, you can get even more brightness.
With a suitable driving circuit, i don't see why LED's can't be used instead of other light sources for most things, as when run pulsed in this fashion they are extremely efficient.
(The only potential downside is the faint whine the coil in the inverter makes - but this could be removed given careful enough construction.)
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i disagree - LED's as light sources have an advantage over most other light sources that you seems to be ignoring - a very fast response time.
All you need to do to get efficiency out of them is hook 'em up to a little inverter - supplying brief pulses of current with a very low duty cycle at about 10 kHz or so - the light will seem perfectly bright and usable, as the response time for even a white LED to go from off to 100% is nothing compared to the time it takes a human retina to notice that the light is already off.
Obviously, this is going to save power - the average power usage would be tiny, the intensity of a pulse would not.
You just can't do that with a incandescent bulb.
The better LED torches already do this - they practically SIP current from a battery, and a penlight sized torch using a single white LED is enough to read by in an otherwise unlit room - left in one place pointing at the ceiling!
Plus it lets you get away with another neat trick too - running the LED at a higher peak current then it is rated for, so long as the pulses from the inverter are suitably short, and the average power doesn't exceed the LED's power dissipation rating, you can get even more brightness.
With a suitable driving circuit, i don't see why LED's can't be used instead of other light sources for most things, as when run pulsed in this fashion they are extremely efficient.
(The only potential downside is the faint whine the coil in the inverter makes - but this could be removed given careful enough construction.)