Apparently, they are not bright enough yet to use as a primary light-source - and there are reliability problems. Noone wants to spend an exorbitant amount for a bulb that fails after only one year - right after the warranty expires.
They are extremely bright and the bulbs last longer than any other bulb. The US militaty uses these:
http://www.surefire.com/maxexp/main/co_disp/displ/pgrfnbr/16/sesent/00
LEDS work on 3.5 volts and low amperage so they are not power hogs. You can run 'em on just about any power source. What you DON'T want to do is run them from a transformer from 120v. You're bleeding off the excess in waste heat. That's why I'm designing a battery powered/solar charged system for a couple of rooms.
You are correct - sort of - about the brightness. LEDs can be VERY bright. Some are now used at the tops of towers because of their brightness and reliability. Radio stations LOVE them! Less need for Tower Monkeys.
LEDS are even being used as tail lights in cars...maybe even headlights by now, I haven't been able to keep up because the tech has been changing so fast.
The problem is LEDs emit light in a very narrow band...IIRC around 20 degrees as opposed to the (nearly) 360 degrees of other sources.
But that's not really as big a problem as it sounds. You can always use more LEDS spread in a pattern that coverse a given area.
There was supposed to be a big development in LED tech this summer. Rumor was HUGE price drops one top of the line LEDs as well as better "whiteness". The desk lamps I use - ten bucks apiece at a dollar store a couple of years ago BTW - Are too bluish for most people. The newer LEDs are producing an acceptable white now...I have a few of those.
Really if I put my mind an dresources to it I could operate my house with solar lighting, a battery bank and small generator for TV, radios, computers etcetera. The only thing I would need Electric power for would be a big refigerator - something Wife and I really don't need now, powering the washer and dryer and electric motors in fans, furnace and such, and of course anything that uses resistance for heat like a hair dryer. There ARE ways around that though, they're just expnsive at the moment.
I'd like to do that not because I'm an enviromentalist - which I am DEFINATELY NOT - or some back to simplicity whacko. It's because the tech is there> It just needs a bit more tinkering.
And the most important reason for using the hi tech lighting and power system is because I CAN.
Plus... then I can tell the high priced, utilities and their whacko unions to go Fark off, hehehehe.
prisoner6
I’ve converted nearly all of my practical and tactical lights to LEDs without issue. Current “Cree” versions are outpacing the older Luxeon LEDs and even better, more efficient LEDs and circuits are on the way.
Given the LEDs life (100,000+ hours), compactness and efficiency over both incandescent and CFLs, the only real hurdle is cost.