Stealth,
I would say 2 years would be tops, hopefully even sometime next year. I think the next generation of LEDs will probably do the trick. I think it is very close at this time.

Regarding distance and lenses: There is a trade off. If you are doing vertical plants, you need all the penetration you can get Then you need the lenses to really get the light focused. . However you give up covering a wider area and a take a 15% energy loss. At this time I am leaning towards the horizontal grow and very close lights evenly distributed. But who knows. It is really still experimental. That is why it is good to be exchanging info and results.
redline Reviewed by redline on . CHEAPER LED UFO, 100 bucks. could i use the mixed blue red 225 led light to grow from seed to flower? or should i use blue for veg, then all red for flower? these lights have more leds than the UFO, what is better? i want it to supplement the CFLs i already have. Rating: 5