the biggest problem with LEDs is that using them for lighting, especially for omnidirectional lighting, is like trying to fit a square peg in a round hole. you have you use an array of dozens of LEDs, specifically placed to mimic a regular light,
The array of led's instead of single, high power one is not imposed by the need to diffuse the light, but because that way it become cheaper to handle the heat and semiconductor defects (a defect in the semiconductor material is of the size of just one atom, but destroys the complete die. So smaller the dies, less of the material get wasted when selelecting just the good ones)
And what is "regular light"? Except last 20..30years, for 1000's of years it was always the cheapes and most optimum working arrangement for the given technology. It is only the last two or three decades, when people suddenly want to pack everything into an incandescent bulb format...
with tons of gadgetry to get them to run properly.
That is just not true.
The LED's are the least demanding light source except of the incandescent (well, with the incandescent I even take the precisely regulated voltage as granted)
All other electriocal light sources require more complex gear, or pose more restriction on it to run properly.
The thing is, because the LED's are so easy to drive, it is the only technology that technically allows to design a ballast running them flicker free, provide galvanic isolation, compensate mains voltage fluctuation, be efficient, small, and with reasonable cost and life, all at the same time. Yes, such ballast is not the simplest one, but unlike with any other light sources, it is feasible, so became a standard.
If you want to strip the requirements down and keep just the efficiency, reliability and cost, you end up with just a series choke and a string of LED's of about the same voltage as is the nominal mains rms behind a rectifier bridge.
If you argue the MV does not need the rectifier, well, you may arrange the LED's in an antiparallel pairs, so each polarity would be handled by one die from that pair. And compare to the MV, for the same power you suffice with less than 1/2 size of the choke: Unlike the MV, you do not have to worry about stable arc and reignition after zero cross, so one requirement less than with the MV...
And you need a heatsink? Well, even with the MV you need a lantern with rather large reflector and refractor bowl. With LED's you suffice with just flat plastic refractor (so way simpler and cheaper to make than the deep bowl), the lantern body then could well act as very good heatsink of no extra cost, of course, when designed accordingly.
Yes, if you want to use LED in an incandescent ficxture, there appear to be a lot of extra gadgetary. But the first thing I then ask: Why do you insist using incandescent gadgetary (socket, bowl,...), when you want to use LED's? Isn't that the stupid thing in the first place?
i don't even expect prices to fall considerably, seeing as how the process of making just one "bulb" is not simple at all,
Well, making single lamp not at all, but making a batchg of 100k+ units become way more expensive with all the tradditional sources: With every step you have to pick each piece one by one. With LED's, majority of the steps (and all the complex and demanding ones) is done in batches of 10k+ pieces. So even when these steps are way more copmplex and demanding, the fact you make 10k+ units at once is, what makes it cheap at the end. Basically all the semiconductor (that includes LED) technology is just designed around that concept, even when that mean way more complex circuit than the "manually" made counterpart. Still, just the ability to produce it in such batches makes it way cheaper.
and as upgrades to the technology occur, they have to redesign and replace the entire fixture rather than just upgrading the parts.
Replacing and redesigning the fixture with the change of the lighting technology happened all the time really since the stone age, the only exception was the last 20..30years, when some greenbrainer tried to convince people, the format of incandescent bulb would be a "golden standard". No surprize, when it doesn't work, it just never did before and I'm convinced it never will in the future...
i can see LEDs successfully replacing fluorescent tubes in applications like TV screens, signage, lighting for things like refrigerators, and other applications where fluorescent tubes have a disadvantage.
where i see a problem occurring is in incandescent replacement and HID replacement; companies like CREE are taking a huge loss by selling their new light bulb for $10, and other companies aren't willing to make that sacrifice just to get buyers. the lighting quality even then is not all that fantastic, and in outdoor fixtures where the LEDs are uncovered, it can be really irritating and unpleasant.
this is why i'm excited about the new "Finally" a19 bulb that's coming out this fall that uses induction technology. i think it could eventually replace CFLs, and if the same ingenuity was used to design HID lighting replacement, induction could easily win there, too. induction lighting is used in a lot of applications like that already, but they haven't really redesigned the fixtures in ten years, and they just don't have the efficiency that LEDs have.
Well, given the technbological complexity and design limitations, the induction does not even have any chance to reach the similar reliability and/or life of regular hot electrode fluorescents or even LED drivers designed with the same budget limitation. Yes, there are induction ballasts models with proven reliability record, but what was their purchase cost? For that price you could have the complete LED system with the same life and reliability, of course, with similar ballast size as well. But the thging is, the market does not want this. The market wants cheap to buy systems. And there, with that budget range, the induction would be simply way less reliable than any other system
Now I'm talking about the cost to cover the production and development, not directly the sale prices. As the LED's bear the "green" and "sexy" patinas, they allow for way higher profit margins, you an not even dream of in any other general lighting technology. This is slowly settling down, but still the gap is there huge. Believe, Cree and others are still making money on the LED products, the only difference to others, it is just not the 95+% anymore, what it used to be few years ago...