2018 light efficiency ultimate battle
- Thread starter aerorev
- Start date
My kind of thread. It's hard to be a passionate indoor grower and not dedicate at least half of your research into lighting.
It's hard to pin down which light is better when there are a dozen metrics to use. Grams per watt is more important to larger growers, as small yields don't pay the bills. A 30% drop in yield for a 5% increase in quality doesn't work out when operating a business.
The current statistic du jour is umols of PAR per joule, with the latest LED models hitting 2.7.
HPS lighting has it's place, I have 54 of the DE 1000w Gavitas and Nanolux fixtures in flower. In terms of raw output, yes they emit a lot of infrared heat, as the technology is still roughly 10% behind LEDs in terms of efficiency. So, a 1000w HPS vs 1000w of COBs will get you roughly 10% less light and 10% more heat.
Some of the LED manufacturers will contend that their 200w, 400w or 600w fixture is comparable to a 1000w HPS, but there's a catch: Yes, under the center of the fixture, some LED panels can create 1300ppf at 6" from the canopy. It doesn't mean they can create the ppfd or yields that an HPS can.
That's not to say there aren't very good LED lights on the market that can compete, or best an HPS in terms of yield. There are, the main drawback to them is the high cost barrier. Typically the ROI of LEDs in a new facility is an easier sell, especially in a hot climate where dependency on air conditioning is strong.
In a retrofit, especially in a cool climate, the ROI can prohibitively lengthy, as the small power savings and no light bulb changes aren't that wondrous. The heat from HPS also works rather well at dehumidification, which often needs increasing in commercial grows who switch to LED.
Now, terpene profiles, wet and dry plant mass, even cannabinoid levels are typically increased with LEDs, due to the lack of IR and lower temps. But, as long as you can maintain 1200ppfd for nonhcarbogated rooms, and 1500ppfd for carbonated rooms, your lighting and presumed yields are considered optimal regardless of your lighting technology.
Fluence is famous for overstating their lights (they make no light that can output 1200ppfd, even at 6 inches) and claim a 1000w HPS makes a mere 700ppfd, which is a blatant lie.
I've personally made 4200ppfd with a 1000w DE fixture at 30 inches from the canopy with a Nanolux deep reflector and Philips Greenpower + bulb, and at 1000w, not on the 1200w setting. The sun puts roughly 2000ppfd down depending on your latitude and season.
Timber makes some really nice COB lights (and kits) but the price is still prohibitive to me. I also believe we'll see more development in quantum boards over the next couple years, and subsequent generations will be improved and cheaper. In 5 years time I imagine we'll look back at today's technology and chuckle at the outrageous prices and low efficiency.
For now, it seems that if you compare a 1200ppfd HPS to a 1200ppfd LED, you're going to get better results in every metric with the LED, largely due to the superior CRI and PAR output of the LED fixture. It may be the same amount of photons hitting the plant, but the HPS has an markedly inferior PAR curve compared to the LED.
I'm talking with a couple LED manufacturers about integrating programmable UV diodes into their fixtures, that can be run independently on either an independent internal timer, or from an exterior one.
Lighting is where we will make the biggest strides in horticulture in the coming years.
It's hard to pin down which light is better when there are a dozen metrics to use. Grams per watt is more important to larger growers, as small yields don't pay the bills. A 30% drop in yield for a 5% increase in quality doesn't work out when operating a business.
The current statistic du jour is umols of PAR per joule, with the latest LED models hitting 2.7.
HPS lighting has it's place, I have 54 of the DE 1000w Gavitas and Nanolux fixtures in flower. In terms of raw output, yes they emit a lot of infrared heat, as the technology is still roughly 10% behind LEDs in terms of efficiency. So, a 1000w HPS vs 1000w of COBs will get you roughly 10% less light and 10% more heat.
Some of the LED manufacturers will contend that their 200w, 400w or 600w fixture is comparable to a 1000w HPS, but there's a catch: Yes, under the center of the fixture, some LED panels can create 1300ppf at 6" from the canopy. It doesn't mean they can create the ppfd or yields that an HPS can.
That's not to say there aren't very good LED lights on the market that can compete, or best an HPS in terms of yield. There are, the main drawback to them is the high cost barrier. Typically the ROI of LEDs in a new facility is an easier sell, especially in a hot climate where dependency on air conditioning is strong.
In a retrofit, especially in a cool climate, the ROI can prohibitively lengthy, as the small power savings and no light bulb changes aren't that wondrous. The heat from HPS also works rather well at dehumidification, which often needs increasing in commercial grows who switch to LED.
Now, terpene profiles, wet and dry plant mass, even cannabinoid levels are typically increased with LEDs, due to the lack of IR and lower temps. But, as long as you can maintain 1200ppfd for nonhcarbogated rooms, and 1500ppfd for carbonated rooms, your lighting and presumed yields are considered optimal regardless of your lighting technology.
Fluence is famous for overstating their lights (they make no light that can output 1200ppfd, even at 6 inches) and claim a 1000w HPS makes a mere 700ppfd, which is a blatant lie.
I've personally made 4200ppfd with a 1000w DE fixture at 30 inches from the canopy with a Nanolux deep reflector and Philips Greenpower + bulb, and at 1000w, not on the 1200w setting. The sun puts roughly 2000ppfd down depending on your latitude and season.
Timber makes some really nice COB lights (and kits) but the price is still prohibitive to me. I also believe we'll see more development in quantum boards over the next couple years, and subsequent generations will be improved and cheaper. In 5 years time I imagine we'll look back at today's technology and chuckle at the outrageous prices and low efficiency.
For now, it seems that if you compare a 1200ppfd HPS to a 1200ppfd LED, you're going to get better results in every metric with the LED, largely due to the superior CRI and PAR output of the LED fixture. It may be the same amount of photons hitting the plant, but the HPS has an markedly inferior PAR curve compared to the LED.
I'm talking with a couple LED manufacturers about integrating programmable UV diodes into their fixtures, that can be run independently on either an independent internal timer, or from an exterior one.
Lighting is where we will make the biggest strides in horticulture in the coming years.
There has been some great analysis done by Ag. Scientists at universities in an attempt to answer this question. The answer changes rapidly, with new technologies rapidly supplanting the old. Currently I believe the double ended, and led both achieve efficiencies of 1.7 par per watt, with lec coming in at 1.5. For comparison old school magnetic 1000’s go about 1-1.1. But it easily cost 4-5 dollars on LED to get the same amount of output you can get with 1 dollar in the HID. It takes a little while to recoup that with Lower electric/cooling costs, if it happens at all.
I still really like double ended and lec as well over the LED yet and that is due not only to the fixture cost but also a rapidly changing market. We are moving from diodes to COB’s to who knows what next. I’ve seen guys in pro horticulture starting to use low voltage led strips in greenhouses. They work great. The wire you put up is also the lighting. Talk about an easy install. No junctions. One continuous band of light up to 100’ long. Grow light in a roll.
Buy a good double ended or if heat is your enemy use lec. Give the LED a couple more years. Probably worth the wait. Currently fixture cost is still very high, but is coming down.
Here is one of the best papers I’ve seen published thus far on the subject.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099010
I still really like double ended and lec as well over the LED yet and that is due not only to the fixture cost but also a rapidly changing market. We are moving from diodes to COB’s to who knows what next. I’ve seen guys in pro horticulture starting to use low voltage led strips in greenhouses. They work great. The wire you put up is also the lighting. Talk about an easy install. No junctions. One continuous band of light up to 100’ long. Grow light in a roll.
Buy a good double ended or if heat is your enemy use lec. Give the LED a couple more years. Probably worth the wait. Currently fixture cost is still very high, but is coming down.
Here is one of the best papers I’ve seen published thus far on the subject.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099010
