"The cost of manufacturing LEDs is dropping. Researchers at Purdue University have developed a way to create LEDs using inexpensive, metal-coated silicon wafers instead of expensive sapphire-based bulbs. This discovery has the potential to bring the cost down to levels competitive with fluorescent tubes. You can stay up to date on news of this development over at the Eartheasy blog."
If LEDs become supper cheap, can you imagine how dramatically lighting will change, especially in large city's like NY?
Its been a while since I've posted, I will as promised discuss the RED and FAR RED Spectrum for LED grow lights; stay tuned!
-Power Bower!
Thursday, June 3, 2010
Tuesday, May 25, 2010
GE's New 40-Watt LED Bulb Will Last 25,000 Hours | Design | GreenBiz.com
GE's New 40-Watt LED Bulb Will Last 25,000 Hours | Design | GreenBiz.com
Just saw this! Another proof CREE makes the best LEDs -GE wouldnt touch anything except the best.
"
Cree is providing the LEDs for the bulb, and the two companies will be showing off the new bulb at the upcoming Light + Building 2010 and LightFair 2010 trade shows.
Read more: http://www.greenbiz.com/news/2010/04/08/ges-new-40-watt-led-bulb-will-last-25000-hours#ixzz0oyNEgmgV
"
Just saw this! Another proof CREE makes the best LEDs -GE wouldnt touch anything except the best.
"
Cree is providing the LEDs for the bulb, and the two companies will be showing off the new bulb at the upcoming Light + Building 2010 and LightFair 2010 trade shows.
Read more: http://www.greenbiz.com/news/2010/04/08/ges-new-40-watt-led-bulb-will-last-25000-hours#ixzz0oyNEgmgV
"
Electromagnetic Spectra of various Light Sourcces
Before addressing Red and Infrared light for your plant's benefits, I thought it would be good to actually know the spectra the sun produces to the many types of light bulbs that can be bought.
I also wanted to clear up what UVA and UVB are specifically. According to http://www.schoolgen.co.nz/ee/e4.factsheet.aspx, "ultraviolet radiation is the band of the electromagnetic spectrum with wavelengths just shorter than those of visible light. Sometimes UV radiation is sub-divided into UV-A (320-400 nm), which is harmless, UV-B (280-320 nm), which can cause sunburn, eye damage and skin cancers, and UV-C ( >nm) which may be lethal. Its corroborated! UVA radiation and thus the Royal Blue and UV LEDs are safe for our eyes; Though I still recommend using sunglasses since your eyes may become fatigued (tired) after looking at such high radiant levels and power we simply are not use to. -We squint our eyes at the sun not because of bright UV light, but because of the visible spectra we see; so looking at bright LEDs in the almost invisible spectra may not cause you to be aware of bright light but its still there. (What eyes 'see' and the brain 'sees' are quite different. Ok, enough with the cautionary compliance. Lets look at the electromagnetic scale firstly-
You should be able to notice how small the visible spectrum really is. Also notice where the micro-wave area is, just after far infra-red band. This is sort of a hint at to what Ill be addressing on the Red and IR spectrum blog post hopefully tomorrow.
First here is the Sun's spectrum-
I also wanted to clear up what UVA and UVB are specifically. According to http://www.schoolgen.co.nz/ee/e4.factsheet.aspx, "ultraviolet radiation is the band of the electromagnetic spectrum with wavelengths just shorter than those of visible light. Sometimes UV radiation is sub-divided into UV-A (320-400 nm), which is harmless, UV-B (280-320 nm), which can cause sunburn, eye damage and skin cancers, and UV-C ( >nm) which may be lethal. Its corroborated! UVA radiation and thus the Royal Blue and UV LEDs are safe for our eyes; Though I still recommend using sunglasses since your eyes may become fatigued (tired) after looking at such high radiant levels and power we simply are not use to. -We squint our eyes at the sun not because of bright UV light, but because of the visible spectra we see; so looking at bright LEDs in the almost invisible spectra may not cause you to be aware of bright light but its still there. (What eyes 'see' and the brain 'sees' are quite different. Ok, enough with the cautionary compliance. Lets look at the electromagnetic scale firstly-
So this is nice but... what does the sun actually produce, since thats what we are interested in artificially creating for the least amount of cost and highest amount of efficiency. We already know LEDs are the most efficient light source out there and will only become more efficient like CPU computer chips. The law I am referring to for computers is Moore's Law, and there is a correlate for LEDs -only makes sense since LEDs are Digital light. -Though I cant recall exactly where I saw this, probably when I was researching CREE on google finance's news ticker early April. So before I go on about sun and artificial lights, Im gonna pose a question to you- have you ever noticed how CFL light (the older ones I suppose now) would make brown/tan pants appear green? Or make medium rare steak look light green meat from Dr. Sue's Green Eggs and Ham story book? I'll answer this question in a moment.
First here is the Sun's spectrum-
Notice the units on the left side of the graph -this shows the amount of POWER (in watts) at each SPECTRA (in nano meters) shine on a one METER by one METER square at sea level. If you were to add up the power at each wavelenght you would then know exactly how much power per meter squared to supply to indoor grown plants. In theory its this easy, but remember this graph shows power relative to differing wavelengths.
Now, its apparently difficult to find spectral radiation distribution graphs for even the most common light sources, at least on line, but i did manage to find one from
Now, its apparently difficult to find spectral radiation distribution graphs for even the most common light sources, at least on line, but i did manage to find one from
So we can see very easily the one individual light source that most accurately emits spectrum closest to Noon Sunlight is the White LED. Also take into consideration the light plants absorb-
The White LEDs are very close to replicating the chlorophyll a & b as well as most of the beta-carotene pigment absorptions. Now since we've already looked at blue, royal blue and UV specific LEDs, we can get very close to 100%artificial replication of plant's needs in the blue spectrum!
I want to hear yawl's comments!
-Power Bower!
Monday, May 24, 2010
Ultra Violet (UV) Spectrum
As promised, I have researched the UV spectrum issue; and as it turns out 380nm (nano meters) is a crucial spectrum most green leafy plants need (like Bell Peppers) in their vegetative state even. Neither Blue nor Royal Blue LEDs supply this spectrum.
Before getting into the science of plants' need for UV light, lets check the Data Sheet for CREE Inc.'s Blue and Royal Blue LEDs. (CREE is the top producer in America of high quality LEDs which last longer -guaranteed 50,000 hrs- and keep more true to their color after 50,000 hrs (80%) than the next leading manufacturer's -Phillip's Lumileads @70% after 50,000 hrs.
Here is the data sheet.
Notice on pg 2 of CREE's data sheet there is a chart for Dominant Wavelength (nm). Looking at Royal Blue the CREE LEDs (Phillip's Lumideads are almost exactly the same) the minimum dominant is at 455nm and dominant max at 465nm. Keeping this in mind scroll down to pg 3; here we can see distribution curves for each color LED CREE produces. The royal blue LED distribution curve is most left curve and peaks right past 450nm and dramatically falls to ~6% radiant power at 425nm.
What this means is the bulk, ~85% or so, of light the LED produces is rang bound from 425nm to 480nm. Which is excellent except we are missing everything to 380nm. Now how do I know 380 is intregal?
I did some searching online since I was curious about UV and ran into LEDgrowlights.info and there Light Wavelengths are posted for plants and whats necessary and not necessary in terms of specific spectrum. Now UV can be dangerous to not only your skin but eyes! So even though LEDgrowlights.info states "315 - 380 nm Range of UVA ultraviolet light which is neither harmful nor beneficial to most plants" still treat this are of the spectrum with respect. Now, wavelengths greater than 380nm are safe, and is just about the spectrum area of Black Lights. Black Lights still can not only cause eye fatigue but over exposure will lead to skin aging, so again be careful and if dealing or exposed with these wavelengths do what you would when in direct sunlight: where Sunglasses and Sunscreen (no kidding).
OK, back to the point, 380nm to 400nm, according to LEDgrowlights.info, is where the visible light spectrum begins and the "process of chlorophyll absorption begins." Still our High Power Royal Blue LEDs from either CREE or Lumileads dont even touch the outer bound of this spectrum range. We are not out of luck though!
I have found wholesale suppliers that provide both High Power and High Brightness LEDs. (High Power is the more useful -more light out put despite the misnomer of High Brightness LEDs, which are the smaller traditional 'looking' LEDs except clear) What I havent worked out just yet is what proportion of these UV LEDs or even spectrum one needs relative to the visible blues and reds (and Infrared or Near Red) LEDs.
I'll touch on IR and red later but for now, we know we need not just blue or even just Royal Blue but UV LEDs to fill in the very important near Blue/Violet side of the scale.
So Now Why is This Important?
Ok several reasons: Pigments, Energy & Protein- there are basically two types of reactions that go on inside a plant- light dependant and light independent. As horticulturalists, we appreciate the science of plants but if your like me we want things to not just start growing but really take off, so we'll possibly touch on light independent later.
Light Dependant reactions are the first stage of photosynthesis. (see wikipedia.org) If you remember 9th grade bio, this is the mechanism plants use to make food -very important for all growing stages of a plant's life. Now these reactions "take place on the thylakoid membrane inside the chloroplast" and is called the lumen (dont confuse this with a measure of light irradiance). The lumen side of the chloroplast is where the light dependant reactions take place because of Photosystem I and II where they "absorb light energy through proteins containing pigments, such as chlorophyll." "When a chlorophyll a molecule within the reaction center of PSII absorbs a photon, an electron in this molecule attains a higher energy level." In otherwords the photon that gets absorbed by the chlorophyll pigment is exciting a domino effect eventually leading to food production for the leaf cell and plant all together.
Now I dont want to bore anyone, my basic point is that pigments are really what alows for specific light colors to feed the plant (as well as other things). And these plants have evolved, if you will, to utilize a high energy form of light, to get food on the table.
Going back to LEDgrolights.info, we see at the bottom of the page a list of wavelengths to each pigment. Though this is a generalization it helps a lot with knowing what to get in a Grow Light or in Building Your Own which I plan to do.
The table is as follows:
Beta-carotene 450nm 480-485nm dual peak
chlorophyll a 430nm 662nm dual peak
chlorophyll b 453nm 642nm dual peak
phycoerythrin 590nm single peak
phycocyanin 625nm single peak
To get an idea of what this looks like would look like, and I stress idea, Im borrowing a graph from Instructables.com.
Still notice this graph and table appear to show no great need for 380nm to 430nm and a simple explanation for this is that this graph and table is for a typical plant vegging. You may even notice that different plants have stronger shade of green on there leaves or even differ in color. Which leads me to reference another source: Jorge Cervantes The Indoor/Outdoor Grower's Bible (ISBN: 978-1-878823-23-6). Which is an excellent source for any horticulturalist! Looking at pg. 160, Cervantes breaks down the exact Photosynthetic response. Unfortunately, he provides the data graphically and I do not have a photo I can link to. You may purchase his book at Barnes & Noble or at Amazon.com.
Still, I can tell you according to Cervante's graph the Phototropic response absorption begins at 350nm with a high ~75% (out of 100%) absorption and peaks at 380nm with ~82% absorption! (High absorption at a specific wavelength implies a neccisary wavelength) The Phototropic response then troughs slowly down to ~470nm @59%, which is still high, and then rises to a peak of 490nm and then to 510nm at 97% and 95% absorbance.
Why those spectrum range's? Circadian Rhythm!
Everything, and that includes plants all the way down to life forms you cant see but still need sun light, work on a biochemical rhythm just like you and I; and as you know, you'll feel well with only the right amount of sleep (darkness) and too much or too little will make you feel, as well as act, differently -this is the same and perhaps more profound with plants.
From wikipedia.org, "Light resets the biological clock in accordance with the phase response curve (PRC). Depending on the timing, light can advance or delay the circadian rhythm. Both the PRC and the required illuminance vary from species to species..." In plants Cryptochromes are responsible for the PRC- "Cryptochromes possess two chromophores: pterin (in the form of 5,10-methenyl-6,7,8-tri-hydrofolic acid (MHF)) and flavin (in the form of flavin adenine dinucleotide (FAD)). Both may absorb a photon; in the plant Arabidopsis thaliana the pterin appears to absorb at a wave length of 380 nm and flavin at 450 nm."
So some light is used by plants to make food, other wavelengths cause the plant to wake up, (absence there of to sleep), vegetate, flower and fruit. I'll end the topic on Blue light with noting the morning, just before and just after sunrise, the sky appears in all shades of blue. Not just that but the sunlight in general leading into and transitioning out of Spring is very Blue as opposed to those Indian Summers with very dramatic Red and Orange sunsets. We see these dominant colors primarily due to the rotation of our Earth about her axis and rotation about the Sun -the Circadian Rhythm. And thats why you need more than just visible Blue light!
Tomorrow, I'll discuss the other side of the spectrum and why IR light is necessary.
-Power Bower!
USE My GOOGLE Search Engine
Before getting into the science of plants' need for UV light, lets check the Data Sheet for CREE Inc.'s Blue and Royal Blue LEDs. (CREE is the top producer in America of high quality LEDs which last longer -guaranteed 50,000 hrs- and keep more true to their color after 50,000 hrs (80%) than the next leading manufacturer's -Phillip's Lumileads @70% after 50,000 hrs.
Here is the data sheet.
Notice on pg 2 of CREE's data sheet there is a chart for Dominant Wavelength (nm). Looking at Royal Blue the CREE LEDs (Phillip's Lumideads are almost exactly the same) the minimum dominant is at 455nm and dominant max at 465nm. Keeping this in mind scroll down to pg 3; here we can see distribution curves for each color LED CREE produces. The royal blue LED distribution curve is most left curve and peaks right past 450nm and dramatically falls to ~6% radiant power at 425nm.
What this means is the bulk, ~85% or so, of light the LED produces is rang bound from 425nm to 480nm. Which is excellent except we are missing everything to 380nm. Now how do I know 380 is intregal?
I did some searching online since I was curious about UV and ran into LEDgrowlights.info and there Light Wavelengths are posted for plants and whats necessary and not necessary in terms of specific spectrum. Now UV can be dangerous to not only your skin but eyes! So even though LEDgrowlights.info states "315 - 380 nm Range of UVA ultraviolet light which is neither harmful nor beneficial to most plants" still treat this are of the spectrum with respect. Now, wavelengths greater than 380nm are safe, and is just about the spectrum area of Black Lights. Black Lights still can not only cause eye fatigue but over exposure will lead to skin aging, so again be careful and if dealing or exposed with these wavelengths do what you would when in direct sunlight: where Sunglasses and Sunscreen (no kidding).
OK, back to the point, 380nm to 400nm, according to LEDgrowlights.info, is where the visible light spectrum begins and the "process of chlorophyll absorption begins." Still our High Power Royal Blue LEDs from either CREE or Lumileads dont even touch the outer bound of this spectrum range. We are not out of luck though!
I have found wholesale suppliers that provide both High Power and High Brightness LEDs. (High Power is the more useful -more light out put despite the misnomer of High Brightness LEDs, which are the smaller traditional 'looking' LEDs except clear) What I havent worked out just yet is what proportion of these UV LEDs or even spectrum one needs relative to the visible blues and reds (and Infrared or Near Red) LEDs.
I'll touch on IR and red later but for now, we know we need not just blue or even just Royal Blue but UV LEDs to fill in the very important near Blue/Violet side of the scale.
So Now Why is This Important?
Ok several reasons: Pigments, Energy & Protein- there are basically two types of reactions that go on inside a plant- light dependant and light independent. As horticulturalists, we appreciate the science of plants but if your like me we want things to not just start growing but really take off, so we'll possibly touch on light independent later.
Light Dependant reactions are the first stage of photosynthesis. (see wikipedia.org) If you remember 9th grade bio, this is the mechanism plants use to make food -very important for all growing stages of a plant's life. Now these reactions "take place on the thylakoid membrane inside the chloroplast" and is called the lumen (dont confuse this with a measure of light irradiance). The lumen side of the chloroplast is where the light dependant reactions take place because of Photosystem I and II where they "absorb light energy through proteins containing pigments, such as chlorophyll." "When a chlorophyll a molecule within the reaction center of PSII absorbs a photon, an electron in this molecule attains a higher energy level." In otherwords the photon that gets absorbed by the chlorophyll pigment is exciting a domino effect eventually leading to food production for the leaf cell and plant all together.
Now I dont want to bore anyone, my basic point is that pigments are really what alows for specific light colors to feed the plant (as well as other things). And these plants have evolved, if you will, to utilize a high energy form of light, to get food on the table.
Going back to LEDgrolights.info, we see at the bottom of the page a list of wavelengths to each pigment. Though this is a generalization it helps a lot with knowing what to get in a Grow Light or in Building Your Own which I plan to do.
The table is as follows:
Beta-carotene 450nm 480-485nm dual peak
chlorophyll a 430nm 662nm dual peak
chlorophyll b 453nm 642nm dual peak
phycoerythrin 590nm single peak
phycocyanin 625nm single peak
To get an idea of what this looks like would look like, and I stress idea, Im borrowing a graph from Instructables.com.
Still notice this graph and table appear to show no great need for 380nm to 430nm and a simple explanation for this is that this graph and table is for a typical plant vegging. You may even notice that different plants have stronger shade of green on there leaves or even differ in color. Which leads me to reference another source: Jorge Cervantes The Indoor/Outdoor Grower's Bible (ISBN: 978-1-878823-23-6). Which is an excellent source for any horticulturalist! Looking at pg. 160, Cervantes breaks down the exact Photosynthetic response. Unfortunately, he provides the data graphically and I do not have a photo I can link to. You may purchase his book at Barnes & Noble or at Amazon.com.
Still, I can tell you according to Cervante's graph the Phototropic response absorption begins at 350nm with a high ~75% (out of 100%) absorption and peaks at 380nm with ~82% absorption! (High absorption at a specific wavelength implies a neccisary wavelength) The Phototropic response then troughs slowly down to ~470nm @59%, which is still high, and then rises to a peak of 490nm and then to 510nm at 97% and 95% absorbance.
Why those spectrum range's? Circadian Rhythm!
Everything, and that includes plants all the way down to life forms you cant see but still need sun light, work on a biochemical rhythm just like you and I; and as you know, you'll feel well with only the right amount of sleep (darkness) and too much or too little will make you feel, as well as act, differently -this is the same and perhaps more profound with plants.From wikipedia.org, "Light resets the biological clock in accordance with the phase response curve (PRC). Depending on the timing, light can advance or delay the circadian rhythm. Both the PRC and the required illuminance vary from species to species..." In plants Cryptochromes are responsible for the PRC- "Cryptochromes possess two chromophores: pterin (in the form of 5,10-methenyl-6,7,8-tri-hydrofolic acid (MHF)) and flavin (in the form of flavin adenine dinucleotide (FAD)). Both may absorb a photon; in the plant Arabidopsis thaliana the pterin appears to absorb at a wave length of 380 nm and flavin at 450 nm."
So some light is used by plants to make food, other wavelengths cause the plant to wake up, (absence there of to sleep), vegetate, flower and fruit. I'll end the topic on Blue light with noting the morning, just before and just after sunrise, the sky appears in all shades of blue. Not just that but the sunlight in general leading into and transitioning out of Spring is very Blue as opposed to those Indian Summers with very dramatic Red and Orange sunsets. We see these dominant colors primarily due to the rotation of our Earth about her axis and rotation about the Sun -the Circadian Rhythm. And thats why you need more than just visible Blue light!
Tomorrow, I'll discuss the other side of the spectrum and why IR light is necessary.
-Power Bower!
USE My GOOGLE Search Engine
Friday, May 21, 2010
Hi All!
Its absolutely gorgeous out, the sun is so bright you'll get a tan in no time... Thats what I was thinking after watching some YouTube vids. There seems to be a fair amount of people really ticked off about the real 'power' these LED lights you can buy for mass deneiro. (Why cant you get a sun tan from an LED grow light? and Is this maybe a missing factor ingetting good fruit yields?)
So after watching: this, and especially this for example, I got to thinking, what if there are spectrum these LED lights are just not providing to 'stress' a plant to get into the flowering stage?!
I've asked some friends of mine, that graduated in Bio and happen to remember a little botany, do plants react to certain types of light even the UV and IR spectrum that we cant see but feel? The answer is yes. And we can see some UV, such as the spectrum Black Lights give off.
He also told me plants are just like women in a lot of ways! They get hormonal, funny but true -plants grow because of hormones and they flower because of hormones. The difference is we want our plants, whether they are Bell Peppers or other types of herbs, to go all out hormonal and produce flowers and eventually fruits.
So, I called up some of these LED Grow Light companies and asked, what are the spectrum these LED lights produce? Could not get a good answer. Im looking for something in nanometers, how is blue and red gonna help me? -Maybe hes worried about someone taking his biz...or He Really Just Doesn't Know or Care!
So Im gonna do a little researching, Im gonna find out what blue and red LEDs produce in actual light and the spectrum they do it in!
Stayed tuned, Im gonna help everyone out with their violet and Pepper indoor-farm!
-Power Bower!
Its absolutely gorgeous out, the sun is so bright you'll get a tan in no time... Thats what I was thinking after watching some YouTube vids. There seems to be a fair amount of people really ticked off about the real 'power' these LED lights you can buy for mass deneiro. (Why cant you get a sun tan from an LED grow light? and Is this maybe a missing factor ingetting good fruit yields?)
So after watching: this, and especially this for example, I got to thinking, what if there are spectrum these LED lights are just not providing to 'stress' a plant to get into the flowering stage?!
I've asked some friends of mine, that graduated in Bio and happen to remember a little botany, do plants react to certain types of light even the UV and IR spectrum that we cant see but feel? The answer is yes. And we can see some UV, such as the spectrum Black Lights give off.
He also told me plants are just like women in a lot of ways! They get hormonal, funny but true -plants grow because of hormones and they flower because of hormones. The difference is we want our plants, whether they are Bell Peppers or other types of herbs, to go all out hormonal and produce flowers and eventually fruits.
So, I called up some of these LED Grow Light companies and asked, what are the spectrum these LED lights produce? Could not get a good answer. Im looking for something in nanometers, how is blue and red gonna help me? -Maybe hes worried about someone taking his biz...or He Really Just Doesn't Know or Care!
So Im gonna do a little researching, Im gonna find out what blue and red LEDs produce in actual light and the spectrum they do it in!
Stayed tuned, Im gonna help everyone out with their violet and Pepper indoor-farm!
-Power Bower!
Tuesday, May 18, 2010
First Day of Blogging
Hi All!
You're here because you like things that are green or at least make things green. I do too, but I live in NYC and can tell you green is a scare color to find, heck if you are a native NYC'er, you'd probably think trees only grow in concrete pots by the street!
The fact is I want to not only look at green lush plants, but enjoy fresh fruits free of pesticides and bugs. I've tried the window boxs -and had the talks with the building superintendents; I've tried those AeroGardens and ended up with dwarf-sized unproductive plants that last for a month or so and then rot... Theres got to be a way to get it right, right?
I determined to do get it right, thats why I have finally decided enough is enough, I am gonna become a DIYer. So stay with me, I am going to provide my research, methods and tinkering here on this blog with photos and videos on how to do horticulture right.
-Power Bower
Next post will be on the light, and all the myriad of grow lights out there.
You're here because you like things that are green or at least make things green. I do too, but I live in NYC and can tell you green is a scare color to find, heck if you are a native NYC'er, you'd probably think trees only grow in concrete pots by the street!
The fact is I want to not only look at green lush plants, but enjoy fresh fruits free of pesticides and bugs. I've tried the window boxs -and had the talks with the building superintendents; I've tried those AeroGardens and ended up with dwarf-sized unproductive plants that last for a month or so and then rot... Theres got to be a way to get it right, right?
I determined to do get it right, thats why I have finally decided enough is enough, I am gonna become a DIYer. So stay with me, I am going to provide my research, methods and tinkering here on this blog with photos and videos on how to do horticulture right.
-Power Bower
Next post will be on the light, and all the myriad of grow lights out there.
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