The new generation of LED lights are highly efficient, work well in tight spaces, spread light evenly and optimize production in both vertical and horizontal applications. Photo courtesy of Forever Green Indoors.
When Washington and Colorado legalized recreational, adult-use marijuana in 2012, thousands of entrepreneurs predicted “green gold” would be harvested in converted warehouses throughout major metropolitan areas.
The historic event reversed decades of prohibition and created huge opportunities for cannabis growers, manufacturers and retailers.
The rush was on.
But like any exciting new business that pops up where none existed previously, the “gold rush” mentality spread rapidly and attracted a large number of individuals with varying levels of expertise. Clandestine cannabis growers with nothing more than a few years’ experience of production in a garage or basement proclaimed themselves “master growers.” Anyone with a subscription to High Times could be a “consultant.” And the authors of elementary-level how-to books on backyard marijuana cultivation were sought out as expert speakers at cannabis business expos and conventions.
The results of this strange brew could be seen in the large number of business failures, fractured partnerships and lawsuits that followed legalization. Many of the early indoor grow facilities felt like they were cobbled together without a coherent plan.
Overall, Colorado growers fared better than those in Washington because vertical integration (which, in Colorado, allows growers to produce marijuana for their own stores) often insulates poorly conceived facilities from the ruthless nature of open market competition. However, the downside for Colorado consumers is lower quality marijuana, less selection and higher prices.
As commercial, indoor cannabis farms were developed, many reflected the status quo prior to legalization. The grow lights of choice were invariably high-intensity discharge fixtures. Easily accessible university research papers, such as studies published by PLOS One (www.plosone.org), were overlooked. Commercial grow operations often utilized metal halides for veg and high-pressure sodium (HPS) lights for flowering, despite peer-reviewed university studies that showed HPS to be the superior grow light for all phases of plant growth.
Old habits die hard.
However, the most successful entrepreneurs are often the ones who remain open to change and adaptable to new technology and information.
Unlike high-pressure sodium lights, LEDs offer the ability to adjust the light spectrum to the needs of specific cultivars, resulting in fuller, larger buds.
LED catches up
At the same time the cannabis industry was expanding, so too were the advances in LED technology. Once regarded as expensive and unproven, LEDs started to take off with a new generation of super energy-efficient fixtures designed specifically for horticultural applications.
Forever Green Indoors CEO Kathleen Sullivan was one of the early proponents of LED grow lights.
“When we first started the company in 2013, the general attitude was that LED wasn’t there yet,” she says. “Many growers had experience with HPS and were reluctant to try anything new. Now, with the new technology, LED fixtures are far better, and we often find that conversations with growers are not centered on LED versus HPS, but rather, on the merits of one LED brand over another.”
There are several reasons LEDs have rapidly gained acceptance in the cannabis community.
First, while HPS lights are a proven source of photosynthetically active radiation (PAR) with a long track record in indoor horticulture, the technology is inefficient, wasting up to 80% of its energy in the generation of heat. That heat can lead to expensive power bills due to the need for complex HVAC systems used to cool grow rooms. LEDs run much cooler and rarely require expensive cooling systems.
Second, LED manufacturers are designing fixtures with a light spectrum specifically for commercial cannabis production. This focus has resulted in highly efficient lights that work well in tight spaces, spread light evenly and optimize production in both vertical and horizontal applications.
And finally, because LEDs can be adjusted for light spectrum, growers can fine-tune the output for a specific cannabis cultivar, which is an important feature that HPS and fluorescent fixtures cannot accomplish due to their static color temperature.
“Tuning the output of light spectra is not only useful between cultivars, but is also useful between growth stages as well,” says Brandon Newkirk, marketing communications manager for LumiGrow Inc., a California-based LED manufacturer. “Different light spectra can be optimal for mother plants, veg and flower. With an adjustable-spectrum fixture you can also address the different needs of plants in the same room without having to move them around.”
However, Utah State University professor Bruce Bugbee, one of the world’s preeminent authorities on horticultural lighting and the author of several papers on the subject, says light quantity is more important than spectrum, noting that studies have shown that well-distributed light over an entire canopy is what leads to the best growth.
Bugbee stresses the importance of obtaining a high-quality quantum meter to measure light output and uniformity.
According to Bugbee, “low-quality quantum meters can be off by up to 30% and give growers information that is not accurate.”
Sullivan also emphasizes the importance of balanced light: “Many LED lights have a high-intensity reading from a lab or university study, but those readings are often taken in an integrated sphere and only show the strongest point of light,” she says. “In other words, they look good, but are not spreading the light evenly. An even distribution of light is as important as the color or intensity.”
LEDs in practice
While LED grow lights are still a relatively new technology, they’re being embraced by cannabis growers in ever-increasing numbers.
One of the converts is Noel Lieske of Upper Left Cannabis in Olympia, Washington.
“LED in the growth stage is a no-brainer, and I’ve never seen plants that looked so healthy and grew so fast,” Lieske says. “The energy savings were also a big factor in compelling me to give them a try.”
Leiske uses a mix of lights in his flower rooms to obtain optimum spectrum and light distribution. In his 340-square-foot flower rooms, he uses seven HPS lights, eight VividGro LED fixtures and 15 FGI 185-watt lightbars.
“I believe this use of mixed lighting has created the optimum setting for flower and has been the most successful overall,” Lieske says.
Sam Calabrese of Erbacce Wholesale echoed similar thoughts.
“We’re glad we made the jump, and LED has come a long way in the last few years. Our LED fixtures have done better than T-5s in growth, heat and power consumption,” he says.
Facility design
When it comes to the design of a commercial cultivation facility, planning is everything.
The “cobbled together” look can be a sign of poor planning and quite often, the result of not consulting an expert in horticultural facility layout. Experts in non-cannabis controlled environment agriculture can save growers a huge amount of headaches and costs.
One such expert is Nadia Sabeh, a licensed mechanical engineer with a Ph.D. in agricultural and biosystems engineering. She runs the California-based consulting firm Dr. Greenhouse (www.doctorgreenhouse.com) and is frequently called to sort out expensive commercial greenhouse designs purchased by cannabis cultivators who find themselves scratching their heads wondering about the right fixtures for their structure.
“In greenhouses, LED can be an effective source of photoperiodic lighting to prevent plants from flowering, even at low intensities, so few fixtures would be needed,” Sabeh says. “However, to use them for supplemental lighting, the large number of fixtures needed to achieve an even distribution of high-PPFD light can shade the plants under normal daylight conditions.”
PPFD, or photosynthetic photon flux density, is a measurement of the amount of light reaching the plant.
“Still, some vine crop growers use LED lamps overhead to increase vegetative production when natural daylight conditions are low (think northern climates) or within the canopy (called “interlighting”) to supplement the crop with specific wavelengths of light to induce certain quality characteristics of the fruit (color, taste, etc.),” she adds.
One big advantage of LEDs is far lower heat output. In a typical industrial warehouse application, cultivators using LEDs have the ability to stack grow racks vertically, with the light source very close to the plants — a scenario that is not possible with HPS bulbs due to higher heat output and clearance requirements.
In practical terms this equates to more efficient use of space.
Soulshine Cannabis co-owner Patrick Wlaznak saw an immediate 20% to 40% reduction in electricity costs with LED. Wlaznak also noticed a reduction in bio pests that he believes can be attributed to lower ambient temperature levels. In addition, he predicts the slight humidity reduction in his LED grow rooms may also decrease the chance of mold and mildew.
Cash Back
Depending on where they’re located, many growers also qualify for rebate programs that can help reduce the out-of-pocket expense of switching from power-hungry HIDs to energy-efficient LEDs.
Sullivan points out that federal utilities are not allowed to offer incentives to use LEDs because of existing laws regarding cannabis production. However, state and municipal utilities are often eager to work with cultivators and can offer rebates of 50% to 70% on LED fixtures to encourage conservation.
“The programs are all different and have different requirements, so it’s hard to keep up,” Sullivan says. “However, FGI has a dedicated staff person whose job it is to learn about utility programs as they evolve and change, and it’s part of our service.”
LED is an evolving technology that is rapidly changing the way cannabis cultivators grow plants both indoors and in greenhouses. As the legal marijuana business expands and businesses strive for more efficiency — and profitability — LED fixtures will play an ever greater role for cultivators looking to reduce costs and stay ahead of the competition.