General consensus on LED lighting?

[MrDanky]

I haven't been around much to witness many grows using LED lighting, but I am curious what the general consensus is? Is it BOGUS or is it legit? I always sniffed it out as bogus, but after looking at a couple grows i wasn't convinced... that i was right or wrong...anyone have anything to say ?

 

[fatigues]

It can be decent, but that effectiveness comes at a significant price tag for top bin LEDs.

However, the vast majority of commercial LED fixtures are crap; this is especially so when it comes to the moderate to cheap end.

That said, when used in combination with other lights, they can be effective at promoting tight node spacing and compact plants.

 

[pHive.8]

It is impossible to say whether LED is good or bad. It's quite simple to be honest.
Plants just look at the amount of photons they get between 400 and 700 nm.

The 1000W GreenPower bulbs are the most efficient HPS bulbs. They give 2000 µmol/s with a powerconsumption of 1040W.
This means they have an eficiency of 1,9 µmol/W.

If you have a led fixture that can produce more than 1,9 µmol/W you are all set and you will have a LED fixture that will work better than using HPS.
The downside is that LED at the moment is quite expensive.
Products that have the same efficiency as the GreenPower lamps are about 8 times more expensive.

Then again you can ask yourself. Why would I want to use LED. If they would have the same efficiency as the most efficient GreenPower lamps what would be the advantages...
All power that isn't converted to light is converted to heat. If LED and HPS are equally efficient it means they both produce the same amount of heat and light per consumed energy. So that's no advantage. The price is still 8 times higher.

But there is an advantage. LED can be used at short distances from the plant.
We have made projects in Holland with both LED and HPS.

http://www.youtube.com/watch?v=dAShtXAsins&feature=c4-overview-vl&list=PLrRHg-q1A6LG3k0Xx3WQA0-hShrNIY7QB
They are producing tomatoes with ePapillon 1000W lights and LED interlight. LED brings the light deep in the crop where you could never come with HPS. These interlight LED's have the same efficiency as GreenPower lamps.


Another possibility is propagation or production of youngplants. LED is 30% more efficient than T5. This reduces the powerconsumption and heat load.
http://www.youtube.com/watch?v=RQDeHMwLwp8&list=PLrRHg-q1A6LG3k0Xx3WQA0-hShrNIY7QB
These guys are producing their salad youngplants in climaterooms with LED. After that stage the salad goes to the greenhouse for further growth under ePapillon 1000W lights. The distance from the LED's to the plants in the climaterooms is very small. This would never be possible with HPS.


In general: Think twice when buying cheap LED's. Do research on their efficiency in µmol/W.
There is a difference between PPF and PPFD.
PPF meanns the total amount of photon between 400 and 700 nm coming from the lightsource.
PPFD means the amount of photons that reach a certain area.

Laser has a high PPFD, but a low PPF. You'll get a very high amount of light on one small spot, but per square meter (or foot) this is very little. That's how LED manufacturers try to trick you. They tell you that under their lightsource you can measure up to 2000 µmol. But they measure only on one spot and not over the total surface.

To see what is efficient, ask the LED supplier the PPF and the powerconsumption! This will show you the efficiency.



LED is the future!
Next year there will be LED products available that are 30% more efficient than HPS. (HPS for us, is GreenPower lamps. Others are just much much less efficient). The price of the LED product will have gone down too. But probably they will be still about 4 to 5 times more expensive than HPS.


Look forward to your ideas on LED!

 

[habeeb]

summary is:

-expensive
-needs many chips spread out over the area for efficiency
-no one fully knows best spectrum
-there only getting more powerful

they do work ,and work well if designed correctly.

 

[growerwannabe]

Agree with DGS. LED is the future. The narrative that is forming is that LEDs used to suck when first marketed as grow lights. They used fractional watt diodes to achieve the 54 watt (or whatever) rating. I think they still sell these on eBay. The square blue and square red low wattage units, which are cheap now. Technology advances. Now they are using 3 & 5 watt chips with varying light output for a spectrum that is advantageous to growing. That was a key piece of missing information in the early days.
We are in the middle of a LED revolution. Now they are designed in the US, then made in China. The Chinese seem to be jumping on the innovation bandwagon now as well. People involved in our line of work seem to be the catalyst for this rapid innovation. We fund the research, and they are happy to do it. They will continue to become more powerful, efficient, and reliable. Also cheaper. I'm talking months, not years. The $900 light I bought 4 months ago can be had for $300. The latest is "chip on board" technology. I am unsure what that means for growing, but the Chinese seem to be excited.
I recently purchased an American made 600 watt light with separate switches for "grow" & "flower". It was my first grow. I had both switched on all the time, as the thing didn't come with instructions. From just this light I got an Amnesia Haze that grew 4' tall & gave 33g. Along with that, I planted 2 seeds in dirt & the AH in a 5-gal bucket. 29+36+33=98g. from 3 plants and I had no clue what I was doing most of the time. There was green algae, brown algae, nute screw ups, etc. I can't compare to other light formats, but I was very satisfied. I feel confident that I could double that by pinching & training. The big LED was expensive. I've been supplementing it with the new 9 watt daylight CREE bulbs from H.D. They are down to $10 and the competition is moving in quickly. One bulb to one clone/seedling works perfectly up to about 50 days in veg. I went nuts with them in the flower tent. I'm testing 6 different hardware store LED bulbs (in clip-on reflectors). Four 9-watt CREE bulbs, two Philips 19.5-watt spotlight type bulbs (daylight & soft white), a GE Reveal 11-watt bulb, and 2 more that I don't recall at the moment. They can be placed anywhere at any angle. Regarding heat... You could probably put a 9-watt inside the foliage right in the middle to light up all the stuff that grows small because it has been light deprived. I love these new bulbs. They work great around the house too, if you're into that sort of thing.
Side note: Coverage area - LEDs basically point & shoot out a straight line. They have started solving this problem. When looking at lights, note the "core coverage area" vs. the "max coverage area". A light with 4'x4' max coverage isn't going to hang at the top of your 4x4 tent and grow whatever you stuff inside. I hang mine 18" from the canopy. I would need a second unit (or a bunch of LED light bulb shaped bulbs with reflectors) to properly light up the area. In fact I will go get a few more this week to replace the CFLs in the veg room. Gotta go all LED.

 

[MrDanky]

wow nice replies. thanks....