The LED efficacy values in that article are 3 years out of date - 2.0 umol/J is the new 1.7 when it comes to LED fixture efficacy these days. At the same time, the HPS ones haven’t really moved since.
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Do you see any improvements in lifespan in LED lighting on the horizon, or is the lifespan already close to as good as it will get?
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What have you seen with LEDs that reach into the UV or infrared spectrums?
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LED lifespan has essentially flattened, so barring any new technology breakthroughs, not expecting to see much of an improvement there. As it is though, it’s very competitive wrt any incumbent lighting technology.
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The obvious thing with those is a drop in PAR efficacy (since UV and IR are not photosynthetically active). The potential added benefits are bactericidal effect and potentially better plant growth but haven’t seen any good quantifications there yet.
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In a similar vein then, have you seen any benefit to green LEDs?
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Thanks! Any more recent articles you recommend?
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If by “green LEDs” you mean direct energy conversion green chips with no phosphor added, then not really. The “green abyss” (drop in wall plug efficacy in the green spectral region regardless of chip chemistry) has remained unbreachable through chip alone over the last 20 years. Otherwise, the use of phosphors is a good substitute and is working well in horticulture lighting since green light is more active photosynthetically than it’s usually given credit for.
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What is your opinion on LED lights that are offering dimming or being able to lower and increase intensity of the spectrum (s).
Is there an actual color/spectrum shift in doing so ? Or, what is actually changing in the LED when decreasing the intensity ? This is a similar concept with HID lights as well offering dimming and select-a-watt features.
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Roxanne - Nothing up to date comes to mind but let me check and get back to you later on that.
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Joe - The color shift related to dimming is generally negligible for horticulture lighting purposes, so the main effect is PAR decrease. That can be useful in the early stages of plant life (clone, seedling etc.) but can also be achieved just by using fewer lights, unplugging some lights or hanging them higher from the plants at those stages. So in the end, there aren’t too many cases where dimming is truly indispensable.
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Any other new advances in LED technology on the horizon besides efficiency increases?
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The bactericidal and fungicidal effect is an interesting advance, still trying to find its footing. Also, the UVA and especially UVB regions are fairly new to LED technology and of potential benefit to improving product quality beyond just yields.
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For a grower who has never used LED lighting and wants to experiment with trying it out, what setup would you recommend?
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A 4’x4’ patch (either in a room or inside a tent) lit with 9 or 12 VIvidGro GroBars (9 for seedlings/young clones and 12 for established plants), at a distance starting with 2’ for yound plants, then 1’. You can probably finish autoflower plants at 6" distance with just 12 such bars. For “regular” cycle plants, use one VividGro V2 fixture placed no closer than 2’ (preferably at 3’) from the plants over the same footprint.
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Ok we’re at time for the AMA. A big thank you to @VividGro for sharing their knowledge. And thank you to everyone who asked these great questions. See you in a couple weeks for the next AMA event.
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Thanks to all for the great questions!
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sorry to have missed this. Just found out. Would like to include you lights in our lighting measurement optimization project.
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Hello Dr, Randov!
Thank you for taking the time to share your thoughts and expertise. We all appreciate the help!
There are two topics/questions I have here and I’m hopeful you could leave a detailed response on both of the topics. Perhaps your personal thoughts and a few links you think would be useful for us.
Will you please explain Light Spectrum, as it applies to phototrophism specifically? Is Green 520nm required for ideal Phototrophism? If so at what levels? Any spectrum examples you could share?!
How does water vapor or humidity effect light? What are some effects or variations you have seen; if there is high water vapor? Does this diminish the light intensity or spectrum? What if there is low water vapor?
Thanks for answering everyone’s questions, it means a lot.
Have a great day!!!
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