just saw this on our weekly newsfeed and thought it was pretty cool:
http://live.psu.edu/story/61223#nw63
not just from an energy saving perspective but from the science viewpoint too
Had a pal a few years ago who grew copious amounts of weed[grass]in his attic/loft under L E Ds.He was an authority on the subject of LEDs and ther light spectrum,energy saving,low heat,very green enviromentally .I dont see him now.Conversation was always a little limited due to him sampling the crop.Best catching him in a morning when he was most lucid.Intresting subject,but highly illegal here.
DON…
well, given how many attic growers are caught when it snows and their roofs are the only ones without snow, I guess using LEDs would be a plus!
I spend most of my time in a state that has a medical-marijuana allowance, and there are several 'hydroponic supply' stores nearby.
I went into one to purchase some planter liners for some large steel pots, as they were the only retailer that had them in-stock within 100 miles.
There was mostly high-pressure sodium and metal-halide lighting for sale (think streetlights,) but there was a smattering of LED lighting available as well. I inquired about the panels, as they seemed to nothing more than colored 5mm LEDs arranged in huge rows. The smaller of the panels were 15 x 15 (225 LEDs) and the larger were 20 by 50 (1000 LEDs!)
These panels were extremely expensive, IMO, running about a dollar/LED. The surprisingly lucid sales associate informed me that while the panels are starting to sell well, crop yield (tomatoes?) was a bit down over the other methods. He cited the lower heat load as one of the big selling points, as well as reduced electric consumption.
His verdict on the LED tech was that it was "not quite there yet." I showed him the light in my pocket, an XTAR WK21 running on a rechargeable, and he called over his tie-dyed buddy to see the wee powerhouse.
When I informed him that the single XM-L in that light was roughly equivalent in output to 50 of the 5mm LEDs, you could see the resin-soaked wheels turning in his head. 
resin soaked wheels indeed! Even aside from growing alternative herbal remedies, being able to supply only the wavelengths plants need should provide significant cost and heat savings and is one of the neatest aspects of this approach.
I betcha thats what the Space Station uses……now that realy is food for thought
DON…
well, whadya know:
http://www.nasa.gov/mission_pages/station/research/experiments/SSLM.html
looks like they’re still using 5mm LEDs, though I might be wrong. Still, good to see everything still looks like something from an Apollo mission 
When my first son was born, he was six weeks premature, no real complications, but he did have to have a few uv light treatments in his incubator. They were basically a 6” x 10” or so rectangular array of 5mm LEDs. So those little pieces of crap do have their uses…. He’s two on Monday, and as strong as an ox. 8)
I know an aquarium plant grower who has started using led lights to grow plants. They are not cheap and usually have red and blue lights as well as white.
It’s interesting that the “action spectrum” isn’t the highest at the typical peak of solar output, as the sensitivity of our eyes are:
Took the words out my mouth…… ;]
My pal will LUV that link.Ile ping it to him later,he will probaly not sleep tonight reading that little cracker.
Told me once that the Human eye sees Green,but weed[grass]doesnt.That also the Human eye sees Greens better than Reds.Hes usually correct on this stuff,so i took it a so.Thanks for the link
DON…
My girlfriend lived in Colorado for a couple years and these were very popular for growing indoors.
http://www.357magled.com/357_magnum_LED.html
These 357 watt LEDs are supposedly equal to a 1000 watt of HID
http://357magled.3dcartstores.com/357-Magnum-Plus-LED-Grow-Light_p_15.html
Ooooh, ultra high tech metal core pc boards! When will we have such technology?
And 357W out with 180 watts in… Kaching! Perpetual motion, here we come!