Light and the LED Zeppelin: Will LED’s Sink or Soar in the Growroom?
An Advanced Grow Feature by Nico Escondido
A Light Introduction
When people discuss indoor cultivation and the lamps they use to light up a growroom, some standard words and phrases are evoked. You have got terms reminiscent of HPS and MH, relating to high-pressure sodium and metal halide bulbs, respectively. You’ve gotten units of measurement which include wattage, lumens or lux thrown around to describe a selected lamp’s discharge or intensity. Lately, however, there were a number of three-letter words which might be used an increasing number of with relatively little understanding. But these words (which might be actually acronyms for larger phrases) may play an excellent greater role in what occurs in growrooms within the very near future… Welcome to Part II of our Advanced Lighting Series.
PAR is a term usually synonymous with golf. But after you check out it in a special light, it may well also mean photosynthetically active radiation – and that may be a term usually associated with serious cannabis cultivation. In essence, the PAR value is a rating for the quantity of usable light that a bulb can emit.
Researchers and horticulturists have found out that PAR values are higher at the ends of the visible spectrum – it really is to assert, inside the red and blue frequencies (or wavelengths) of light. The elemental PAR zone includes most of this visible spectrum, ranging from about 380 to 750 nanometers (nm) in wavelength. Blue frequencies of the spectrum occur at wavelengths around 450 nm, and red somewhere near 650 nm. These wavelengths directly correspond to the quantity of photons being sent to the plants, and this, in turn, affects plant processes akin to photosynthesis, plant tropism and even stomatal action on leaves (the outlet and closing of leaf stomata for respiration).
Big-time growers are always searching for methods to tweak, supercharge and optimize their gardens, because they know this results in superior marijuana. Advantages in light utilization and increased photosynthesis can obviously help create larger yields and more potent buds. The most important to bear in mind is that not all light emitted by your bulbs shall be usable by your plants. For this reason, growers must decide what spectrum is healthier for their particular crop.
The light-emitting diode, or LED, was invented in Russia within the mid-1920’s. You’re thinking: Who cares where it was invented? But the real fact here’s when it was invented – nearly 85 years ago.
The point is that it has taken an extremely long time for this technology to come back into use, and this present day essentially the mostsome of the most limiting factor with LED’s remains the price of developing the technology. Manufacturers are just now hitting the market with LED products which might be actually precise enough and powerful enough to light indoor gardens all alone. Inside the next five to 10 years – assuming these new LED lamps work well – you may expect to look a giant increase in market volume for LED’s as the price of this technology begins to move down. With that said, let’s study the fundamental advantages of LED lights, moving gradually into the more technical aspects.
To start with, LED lamps use somewhere around one-fifth the ability of ordinary high-intensity discharge (HID) lighting. One of our recent test products – the UFO LED, manufactured by HID Hut (and depicted on our February 2008 cover) – uses 90 watts while still putting out just as many lumens as a 400-watt MH bulb. Obviously, this amounts to a fairly large savings in power consumption and electricity costs.
Additionally, LED’s give off a lot less heat than any conventional HID lamp. Gone are the days of air-cooled lighting systems and the necessity for industrial-strength exhaust fans – not to mention showing up on the thermal-imaging screens of narco-copters flying overhead. The most recent LED models, which include the UFO, have built-in fans to cool the tiny bulbs, making standard growroom ventilation and air exchanges more than enough to keep room temperatures at optimal levels. Not too shabby.
So what concerning the spectrum? Well, here’s where the technology side begins to return into play. It’s worth mentioning that each of these little LED’s can cost the manufacturer upwards of $10 each. When you’ve got 90 LED’s in one lamp, things start to get extremely pricey. The major to keeping this cost down is for the manufacturer to settle on LED bulbs that allows you to be more cost-efficient for the patron. The trick, however, is to not compromise on the most efficient spectral wavelength in your plants. As it stands now, the most efficient valuable LED products in stores (and online) can cost between $550 and $650.
Still, while $600 could seem pretty high for a single-unit lamp, the argument for it’s easy: Savings in energy consumption repays the pricetag after only a year of use. Manufacturers understand, however, that unless the effects are overwhelmingly positive, many indoor growers will remain wary. However, once you consider the charges of ballasts, reflectors, bulbs and cooling equipment for conventional HID lamps, the value gap closes quickly.
And so spectrum becomes the trump card. Because LED companies can choose diodes based on the color they emit, they are able to choose the fitting spectral frequencies for cannabis plants to thrive in. It is a lot harder for HID-bulb manufacturers, although it may be noted that there are ways for them to achieve this (and this can be covered partially III of this series). In creating LED products, a compromise is normally reached between optimal color wavelengths and value; this form, the associated fee tag doesn’t become prohibitive, and the plants will grow in addition or better than they might under conventional HID lighting.
The UFO, as an example, utilizes two spectral wavelengths; one red and one blue. When the lamp was going though its prototype testing, trials found that with the red diodes at 455 nm and blues at 627 nm, some minor stretching occurred in the course of the flowering stage. To combat this, the company tweaked the lamp, stepping up the number of blue diodes from 10 to 20 out of 90. While the company’s founder acknowledges that he would have preferred to take advantage of 660s rather than 627s, the fee of doing so would have made the product five times costlier, and that just doesn’t work for home or hobbyist growers. It has been all these adjustments (with more to return) that have helped LED’s become viable options for indoor growrooms.
Looking toward the long run, it is going to soon be possible for LED lamps to hit every possible color within the spectrum that a plant could want, and to offer it inside the exact amounts that cannabis plants need. But presently, LED’s like the UFO have produced yields akin to or better than their HID counterparts in initial trials (see ends in final section), and have simultaneously saved growers money on electricity while adding better security and growroom atmosphere than do standard HPS and MH bulbs.
To give some added perspective on the sheer costs of developing the brought about its full potential, High Times got an inside scoop on the longer term of LED lighting straight from China – the hub of LED research, development and production.
Preliminary reports have stated that a diode measuring two by two inches (that is a really large diode compared to standard LED’s) has been manufactured in China and is currently within the testing phase. Approximately a half-dozen of these diodes were created in a clean room, as microprocessors will be, with only a small percentage of them working for a brief time period. Still, the 200-watt diode, that is a blue, phosphor-coated bulb, reportedly emits 200,000 lumens!
While the price of materials and actual construction are negligible, the research and developmental costs for this project had been estimated at 60 million yuan, or $8 million – over $1 million per diode. As always, once mass production starts, the price of these diodes will drop fast… but starting at a million per, it’s going to be not less than 10 years before we see anything like that in a growroom.
All plants absorb light via pigments corresponding to chlorophyll A, chlorophyll B and carotenoids. This light energy, often known as photons, is converted into usable plant energy by the excitation of electrons in the plant cells. This energy becomes the key catalyst in photosynthesis. Without this energy, the plant could be unable to provide food for itself and grow. Without this energy, there could be no buds or resin production of any kind.
A graphic of the absorption process within leaves is depicted in Figure 1.1.
The graph shows the absorption rates of two separate pigments (chlorophyll A and B) and breaks down the absorption spectrum by wavelength or color. With this information, it’s much easier to peer the importance of providing proper spectrum for indoor marijuana gardens. As a guide to raised understanding what bulbs can and cannot supply, now we have compiled several graphs let’s say most of the more prominent bulb types available on the market today (see figures 1.2, 1.3 and 1.4).
Bulbs needs to be ready to deliver their light to cannabis gardens with a force as almost the sun’s natural power as possible. Unfortunately, bulbs like fluorescents or incandescents are only strong enough for supplemental lighting, or for use in nursery lamps when baby clones are still rooting. Using lights that aren’t powerful enough for adults will end in spindly, leafy plants as their branches stretch to collect more light.
Another important consideration regarding spectrum involves using supplemental lighting to atone for the dearth of a whole spectrum. A well-known experiment conducted in 1950 by Robert Emerson resulted in the discovery of what we now call the Emerson Enhancement Effect. In principal, the effect states that once shorter wavelengths (i.e., blues or oranges) are supplied in conjunction with the longer wavelengths (together with reds at 690 nm and higher), absorption and photosynthesis occur at a faster rate than the sum of both colors acting alone. The rationale this happens is because separate photosynthetic processes, called photosystems, occur inside the leaves and are relating to the express leaf pigments discussed above.
As research progressed, it turned out that these systems can work together within leaves and that each actually works better when functioning together. Thus, it can be best for indoor growers to mix opposing wavelengths when supplementing gardens in place of use the normal HPS/ MH mix. Observing the spectral coverage of assorted bulbs, we notice that fluorescent bulbs are a great option for supplemental light. Nearly all people first thought that LED’s would also be an excellent source of supplemental light, but as developments continue, some are now claiming that they are the following all-in-one lamp. With prices dropping in LED technology, more manufacturers like HID Hut will probably be ready to produce fuller-spectrum LED lights, making the longer term even brighter than we would have anticipated.
Electroluminescence (EL) is both an optical and electrical phenomenon through which light is emitted by a cloth in response to an electric current being undergone it. LED’s emit a sort of EL using a semiconductor diode, in comparison to the light emission caused by heat or incandescence (resembling in a conventional household bulb), or from the action of chemicals or chemoluminescence (as in HID bulbs like HPS, MH and mercury vapor).
The specific colors emitted by LED’s rely on the sort of semi-conducting material throughout the diode. The colors of light from an LED should be would becould very well be of the visible spectrum, but they are able to also be infrared or near-ultraviolet in addition. As mentioned earlier, LED’s can also be manipulated to offer off white light, that is the light created during the combination of each of the colors of the visible spectrum. Sometimes bulb manufacturers put various styles of coatings on their bulbs to realize white light, but LED’s can combine different color diodes to provide this same effect. Blue diodes might be added to red and green LED’s to create a fuller spectrum and make a whiter light. Whiter-light-emitting bulbs, equivalent to fluorescents, are obviously a better option for indoor gardens thanks to their fuller spectrums. The one question then is whether or not the light source is robust enough to deliver that spectrum to the plants effectively.
And that’s the million-dollar question: Are LED’s the wave of the long run? Obviously, there are big savings in power usage in addition as heat production, and overall security is enormously better. But will they yield bigger? Will they yield super dank? We’ve presented the entire facts, but ultimately the answer to that may only be determined by you. In the event you’re still having trouble figuring it all out, here’s a number of more facts straight from the High Times Cultivation Labs:
In three separate trials, a high-powered LED (prototypes of HID Hut’s UFO) was run in side-by-side experiments – once against a 400-watt MH bulb, once against a 400-watt HPS bulb, and once against a 600-watt HPS bulb. These trials used exactly a similar conditions on each side of the fence. The plants were cuttings taken from a single mother; the medium and grow systems were a similar; and the nutrients and atmospheric conditions were kept identical. The best variable was the lamp provided. And, as usual, the effects varied.
In Trial A, the clones were placed in a three-by-six-foot box that was divided evenly in half. An ebb-and-flow table on either side shared an analogous grow medium and reservoir. Subsequently, the LED lamp yielded 12% more than its counterpart, the 400-watt MH.
In Trial B, similar systems again pitted the UFO against a 400-watt HPS, only this time the LED side took an additional week to complete. Some concern arose over stretching, as the clone grew to touch the UFO. This ended in a call to increase the blue diodes in a second prototype, and it can cause an increase in wavelength for the red diodes, consistent with the manufacturer. Subsequently, the LED side yielded 5% below the HPS side did.
However, it was reported in Trial B that there were markedly different potencies, with the LED plant producing a lot more resin. Speculation exists that the dearth of wavelengths aided in this process, as abnormal stresses had been known to increase the production of resin glands. Final calculations taking into account the extra week of flowering time on the LED side found that when it comes to grams yielded per kilowatt hour (KwH) consumed, the HPS yield was one-fourth that of the LED side.
In Trial C, the grower found similarities to both previous trials. While the LED yielded below its counterpart, this test pushed the boundaries of the LED by pitting it against an improved 600-watt HPS bulb. Resin production on this Cali-O strain was up after just four weeks of flowering, but finally, the yield was around 20% less. However, the grower did note that the volume of money saved in electric costs compared against the fees of the 600-watt HPS was almost enough to offset the profits lost on yield. An enticing side note in this trial was that the plant on the LED side needed considerably less watering than the plant on the HPS side. It can be possible that it truly is by reason of lower surface temperatures inside the soil medium, or because the plant wasn’t driven as hard and thus drank less.
Anyway you slice it, this one’s a real mind-bender. Given the chances for vast improvements down the line, the LED revolution could rather well be underway already. Will the LED Zeppelin (or the UFO) take off and change the realm? For the prevailing, things are certainly looking up.
Related: Let There Be Light