New high powered LEDs

[Gibs]

I really like LEDs and, at least theoretically, they'd make ideal grow lights. Problems so far have been initial cost and (relatively) low lumen output. Enter the new generation of high power, high efficiency LEDs:

 

http://www.luxeonstar.com/item.php?id=5145...=LXML-PD01-0040

 

There are a few manufacturers making these next gen LEDs (Cree, Lumileds, Seoul semiconductors). From my research - that is, geeking out on candlepowerforums - i figure the best bang for buck to be had is with the new Luxeon Rebels. I've ordered a bunch of the red & blue versions of these. Red & blue because white light is quite inefficient; clorophyll absorbs most strongly in blue & red and reflects the rest. Though it's hard to gauge whether the output will be enough to use the LEDs as the primary light source. The luxeon rebels are tiny, fiddly motherfuckers, and i don't really know what i'm doing, but it'll be a fun experiment.

 

LED Pros:

- low heat emission

- low power

- really long lifespan (~50k hrs)

- no wasted spectrum, so high efficiency

- control over amount of blue & red for optimal lighting during growth cycle

 

Cons:

- high initial cost (though this is getting lower all the time)

- few if any usable commercial products

[Shithappens]

$13.49 ea when getting 250+ damm how many would you need to do a grow??

 

say 700 * $13.49 = $9443.00

 

Plus a year or 2 of soldering

 

Plus a power supply to power them all

 

VERSE

 

a HPS $250 bulb shade and ballast?

[Gibs]

$13.49 ea when getting 250+ damm how many would you need to do a grow??

 

say 700 * $13.49 = $9443.00

 

Plus a year or 2 of soldering

 

Plus a power supply to power them all

 

VERSE

 

a HPS $250 bulb shade and ballast?

 

Not sure where you're getting those numbers from. These LEDs are about US$2 each, see the link in my first post. These are much higher powered LEDs than your little red blinky lights of yore. I'd estimate that you'd need far less than 700 of them to get some good output for growing.

 

Nobody's suggesting the initial cost will be comparable to HPS bulbs or whatever else, that's not the point.

[Tom]

Get a load of this new invention from the land of Oz, Solid State Lighting.

 

[SukonmiSkunk]

yeah i seen this on the new inventors too the other night.. and ive goto say.. with my previous thoughts on LED's... and that is.. they are crap.. and will never grow anything more than lettuce.. has opened my eyes... all tho i still think these are useless.. as MJ needs heat to produce resin.. and these produce none.. meaning.. you will HAVE to heat your room... so.. i guess in theory.. the money you save on power running these LED's.. youll just be spending that and probably more on heating your growspace..

 

with that said.. if youre in a part of the world that NEEDs to have their grow space heated.. then these could come in very handy.. providing you get the % of spectrums right

 

I still dont see these producing buds as fat and solid as a HPS globe...

[Gibs]

Interesting...didn't realise heat was that necessary. There are actually some high powered LEDs that just came out (Cree I think?) that operate in the UV spectrum. Not sure if there are any cheap infrared ones. If there are, theoretically it might be possible to generate the required heat directly with LEDs instead of from say waste heat from bulbs or a heater. All comes down to how efficiently (power- and cost-wise) you can do it. Edited July 12, 2007 by Gibs

[Al B. Fuct]

I'm not so sure that SS is right about cannabis plants needing 'heat' to make resin- I guess it depends upon what you define as 'hot.' My flowering area runs smack-dab between 24-25.5C all the time.

 

Now, what SS is right about is that LEDs, even the zooperdooper Philips Luxeons, simply don't make enough luminous output to grow cannabis. Don't care what spectrum the light is in if there's not enough intensity to drive photosynthesis. The Luxeons make as much as 140 lumens in single colour. Consider an ordinary 18W CFL will make about 1700 lumens.

 

FYI, luminous intensity from several sources does not add to give more lumens. Put a 1500 lm CFL next to another 1500 lm CFL and a light meter will read- wait for it... 1500 lumens. Putting one light source next to another does NOT make either one brighter, which is what luminous intensity is a measure of. If you want to grow plants, EACH of your light sources will by itself have to be of sufficient luminous output (brightness) to support photosynthesis.

 

When LEDs start punching out at LEAST 10K lumens each- we'll talk again. Until then, LEDs are very interesting, very expensive and very much a waste of time and money for growing cannabis.

[freddie]

There is a thread on another forum showing a HPS vs LED grow. I hope it's OK to give a link to other mj forums. If not then I guess a MOD will delete it.

 

http://www.icmag.com/ic/showthread.php?t=5...p;highlight=LED

 

The LEDs do OK by the looks of it. Alternatives to HPS are going to have to be found soon as global warming becomes more of an issue.

[Gibs]

I'm not so sure that SS is right about cannabis plants needing 'heat' to make resin- I guess it depends upon what you define as 'hot.' My flowering area runs smack-dab between 24-25.5C all the time.

 

Now, what SS is right about is that LEDs, even the zooperdooper Philips Luxeons, simply don't make enough luminous output to grow cannabis. Don't care what spectrum the light is in if there's not enough intensity to drive photosynthesis. The Luxeons make as much as 140 lumens in single colour. Consider an ordinary 18W CFL will make about 1700 lumens.

 

FYI, luminous intensity from several sources does not add to give more lumens. Put a 1500 lm CFL next to another 1500 lm CFL and a light meter will read- wait for it... 1500 lumens. Putting one light source next to another does NOT make either one brighter, which is what luminous intensity is a measure of. If you want to grow plants, EACH of your light sources will by itself have to be of sufficient luminous output (brightness) to support photosynthesis.

 

When LEDs start punching out at LEAST 10K lumens each- we'll talk again. Until then, LEDs are very interesting, very expensive and very much a waste of time and money for growing cannabis.

Interesting post, but you're a bit off about luminous intensity. To think about it intuitively: You put two light sources together and you double the rate at which photons are emitting. If the light sources are shining in the same spot, you'll double the amount of photons hitting that spot. So if your meter is in that spot, twice as many photons will be hitting it. You can verify this yourself with a lux meter. So if our base light source isn't strong enough we simply add more to produce more photons, which are the base particles that provide energy for photosynthesis.

 

So yeah, the points which make LEDs seem like they might make viable grow lights are:

- We can choose to emit only the wavelengths that are required for photosynthesis, which makes for perhaps a ~70% increase in efficiency over a white light source

- Light source can be placed as close as you like because of low heat generation

[Gibs]

There is a thread on another forum showing a HPS vs LED grow. I hope it's OK to give a link to other mj forums. If not then I guess a MOD will delete it.

 

http://www.icmag.com/ic/showthread.php?t=5...p;highlight=LED

 

The LEDs do OK by the looks of it. Alternatives to HPS are going to have to be found soon as global warming becomes more of an issue.

Thanks for the link, that was an interesting read! They aren't using high output LEDs, but still the LED system is doing surprisingly well. I'd really like to see the same experiment with higher output/higher efficiency LEDs.