Greenfingers1987
Active Member
Hi guys can someone pleaae explain to me how leds n cfls are cheaper to run than hps please
Cheers guys
Cheers guys
Led + cfl cheaper than hps
- Thread starter Greenfingers1987
- Start date
churchhaze
Well-Known Member
Who said this? Most LED and all CFL are more expensive to run than HPS. Only more modern LEDs (more expensive) will cost less to run than HPS, but the startup cost makes HPS continue to look very attractive.
thetr33man
Well-Known Member
Plantmax LU-1000/DE - 1000 Watt - Double-Ended T40 - High Pressure Sodium = 150 lumens / watt.
Many new gen LED's get160l/w or higher, some over 200l/w and last 3x as long as a hps bulb. Course it isnt all about lumens, but its an easy way to demonstrate the difference. Also with HPS, light goes everywhere, both up and down, with LED it only goes one direction, which is helpful for most growers. Many say LED spectrum is better also. CFL is generally crap and only good for some because of its low entry price, still beats incand tho.
Many new gen LED's get160l/w or higher, some over 200l/w and last 3x as long as a hps bulb. Course it isnt all about lumens, but its an easy way to demonstrate the difference. Also with HPS, light goes everywhere, both up and down, with LED it only goes one direction, which is helpful for most growers. Many say LED spectrum is better also. CFL is generally crap and only good for some because of its low entry price, still beats incand tho.
IMHO, the simple answer is that HPS has a high percentage of green spectrum light and over 24% the green light is ignored/reflected by the plants... this is the reason plants are green (see attached study).
LED fixtures have the ability to "target color spectrums". Most LED fixtures sold have a high percentage of red light and a small percentage of around 10% blue light. There is a study that shows that plant growth increases with blue light up to 50% in a blue/red mix of light. A few LED fixtures add some "white light" LEDs... this in essence adds some green light but not enough to be above 24% green. It is this control of the color spectrum that gives LED the leg-up on HPS.
CFLs and FLs are close to the efficiency of LEDs but "most" CFLs or FLs produce white light which has a high percentage of green light... the same disadvantage as HPS. However, one brand of CFLs targets "color spectrums" like LEDs instead of "color temperature" plus has low heat and low entry price which is ideal for the small closet grower.
VeggieMAX (50% blue) - http://www.amazon.com/VeggieMAX/dp/B00TH3SECC
PowerMAX (24% green, balance split between blue/red) - http://www.amazon.com/PowerMAX/dp/B013YZYC6U
FlowerPOWER (10% blue, 86% red) - http://www.amazon.com/FlowerPOWER/dp/B018PSHMYU
If you buy into the idea that HPS has too high of a percentage of green, then it stands to reason that augmenting HPS with blue light would decrease the percentage of green light and thereby increase the overall plant growth efficiency in terms of GPW.
PowerBLUE - http://www.amazon.com/PowerBLUE/dp/B00YELLHP8
(another attached plant study shows that up to 50% blue light increased plant growth).
If an experienced grower is interested in researching lighting efficiency in small grows (2' x 3') using various HPS/LED/CFL lamps and having most of their hard costs reimbursed, then please send me a private message.
RM3
Well-Known Member
Seems the scientists at NASA would disagree ,,,,,,,,,,,,
(...)
Green light.
Green light (500-600nm) falls between broad-band blue and red light
along the PAR energy spectrum. Green often is disregarded as an unimportant
waveband in photosynthesis because absorption spectra of extracted leaf chlorophyll
pigments indicate very weak absorption in the green region of the PAR. Because
chlorophyll has major absorption peaks only in the red and blue regions, researchers
initially selected first red, later blue, LEDs for first-generation LED arrays to support
plant growth. However, intact leaves do absorb considerable green light, and in a
relative quantum-efficiency curve for photosynthesis vs. PAR wavelengths, some
wavelengths of broad-band green actually are more efficient than certain
wavelengths of the blue band. Overall, however, broadband green is slightly less efficient than broadband blue. However, when leaf canopies close, red and blue light are absorbed strongly by upper or outer leaf layers, whereas green light penetrates to interior leaf layers, where it subsequently is absorbed and drives photosynthesis of the inner canopy (14). Thus, light sources containing some green can be more effective in stimulating crop growth than are red + blue sources alone,much as when
foliar canopies are closed. When applied together with blue light, green has effects
opposite to blue on stomatal aperture (15). Yet another useful feature of green light
is that the human eye perceives red + green + blue (RGB) light as white light, so if all
three wavebands are present simultaneously in plant-growth light, researchers and
growers are able to visually evaluate the stress status of crops, the incidence of
physiological disorders, and “true” leaf color (the way it looks outdoors), whereas if
only red + blue are present, green tissue looks purple, grey, or black, and
physiological stress or disease diagnosis is difficult(...)
(...)
White light.
The often-confusing issue regarding which colors or proportions of
colors to select for SSL applications with LEDs can depend on species, cultivar, stage
of development, and intensity of available light. In some ways, the use of LEDs for SSL
is causing us to rediscover the value of white light for plant growth and development.
Because of all the complications involving LED color selection and the range of
possible plant responses, the question often is asked regarding whether white should
be the LED color of choice for plant growth. It turns out that white LEDs actually are
blue LEDs with a phosphor coating the inside of the light-focusing lens mounted over
and around the diode. Energy losses associated with the secondary broad-band
photon emissions of the excited phosphor make white LEDs significantly less
electrically efficient than emissions from pure monochromatic blue LEDs (16). As
well, the proportions of red, green, and blue wave
bands in white LED light vary widely among cool-white, neutral-white, and warm-white LED types,
none of which are a close match for the RGB distribution of midday solar light. It actually would be
more electrically efficient to make white light from monochromatic RGB LEDs than to
use white ones. Nevertheless, inclusion of a few white LEDs on an array may have
utility in terms of achieving certain proportions of broad-band color in case green LEDs are not included.
(...)
from here,
http://ntrs.nasa.gov/search.jsp?R=20150009399
rkymtnman
Well-Known Member
they aren't.
400 watts of LED costs the same as 400 watts of CFL costs the same as 400 watts of HID
If you noticed, one of the scientists on the green light research study I attached was from NASA.
The paper you attached was an opinion paper, not research. While that does not make it good or bad... opinions are like assholes, everyone has at least one.
In my opinion, research is needed that compares the GPW(Grams Per Watt) and CPG (Cost Per Gram) produced from the various light sources in controlled environments with all other factors equal.
I am willing to partially fund that research. Relevant research trumps opinions.
True, but the GPW(Grams Per Watt) and CPG (Cost Per Gram) produced will be markedly different.
RM3
Well-Known Member
rkymtnman
Well-Known Member
way too many variables to quantify though. growing style, growing method, skill of grower, environment, strain, etc, etc.
rkymtnman
Well-Known Member
hell, i could save alot of time and just make hash from seedlings. you might be on to something RM3 lol.Been experimentin with different lights for years Hell I even use UV on seedlings
.
View attachment 3672347
I will be coming out with a UVB augmented Grow Light later this year. I am designing it to be run 3 hours a day to provide a tropical equivalent daily dose of UVB.Been experimentin with different lights for years Hell I even use UV on seedlings
Nice pic. First time I've seen trichomes on small seedlings. Have you ever tested the amount of THC in your grows?
RM3
Well-Known Member
I run UV thru out with same light timing as every where, seedling/clone, veg, flower. I also run a lot of blue in flower compared to red. It's why I use T5's so I can mix and match different bulbs, I don't grow buds, I grow trics
I have had a few tested,,,, lowest was 25% but IMO it doesn't mean much
1st pic Blue Dream WEEK 3, 2nd pic same plant WEEK 8
.
Greenfingers1987
Active Member
Cheers mate so why do people say leds are cheaper to run than hps
Greenfingers1987
Active Member
Rm3 brilliant pics mate 
RM3
Well-Known Member
rkymtnman
Well-Known Member
they say that but it isn't true to a point. a 400 watt led will produce less heat than a HID so it will be slightly cheaper to cool your tent with led than hid. but you still will have to cool a tent with either in it.
an led is more efficient (especially the better ones) at converting electricity to light.
it really depends on your growing style i think. if you grow 4 ft tall plants, a 400 hid hung vertically in the middle would give better results than hanging an led above those same plants.
churchhaze
Well-Known Member
Can you show us an example of an R+B lamp producing more than an equally powered HPS lamp? I would love to see this "efficiency" from having less green translate into tall, healthy, and productive plants...
RM3
Well-Known Member
Tis rare I know, but I'm thinkin we agree here
churchhaze
Well-Known Member
If you're germinating lettuce seeds, R+B might be the perfect spectrum, but in order to have a light that can penetrate the top level canopy, green and yellow are needed. If you tried to light 3-4 foot plants with R+B, in order to get enough PPFD (1000-1500umol*s^-1*m*-2) you'd end up frying the top canopy to a crisp because none of the light would penetrate.Tis rare I know, but I'm thinkin we agree here
Besides that, red light without being balanced by "bad" wavelengths throws shade avoidance completely out of wack as lower branches don't realize they are covered and need to make it to the canopy.
Then NASA came out with that "opinion" article basically saying a lot of the same things people on this forum have been saying for years.. (that green penetrates)