LED Lights Lead the Way in Cannabis Cultivation

How did you get interested in the cannabis industry?

David Cohen: Well, I think the cannabis industry became more interested in me before I was interested in it, and I can explain that. I’ve been in LED lighting to various degrees for about 20 years, really since the first LED lighting fixtures came out. I was in Europe for five years, running a couple of different companies there.

I had Osram as a customer and when Osram bought Fluence in 2018, they wanted to hire a CEO to drive the business because the founders were going to exit. So, they reached out to me and said, “You want to come take a look at this company in Austin, Texas?” and one thing led to another, and that’s how I took the job.

It wasn’t like I was seeking it out. It kind of found me. But once it found me, it’s been a really great relationship. The cannabis industry for my company and for myself has been a spectacular, spectacular experience.

A lot of people set out as a mission to go get into cannabis. And it’s not that I didn’t want to, I just really never had thought about it back in 2018. But what they wanted to do with the company was very intriguing. And when I took a look at the market and the growth potential, I was hooked and then I really started learning about growing cannabis and what the different customer needs were and all that.

Can you tell us a little bit about Fluence?

Cohen: Fluence was founded by three gentlemen in Austin, Texas in 2015. They had an idea that they could make a kind of superior grow light and bring it to market. And by about 2016 or 2017, they had not only come up with a great set of products—a small portfolio of products—but they were also taking advantage of what was going on in cannabis at the time because a lot of the big players in lighting were quite hesitant to get into this space because of their boards of directors, their ethical policies, and whatnot. There were a lot of companies that wouldn’t touch it.

Fluence came up with a great product at just the right time when really Canada and Colorado were taking off and got the lion’s share of the market by bringing really superior products with a ton of research behind it, and that really just put the company on an unbelievable growth trajectory.

By late 2017 or early 2018, they realized that in order to keep growing at the pace that they were growing, which is essentially doubling revenues every year, that they would need to go find either some outside money to fuel the growth or sell the business. So, they elected to sell it, which obviously opened up a great opportunity for me. I took over in 2018 and from 2018 to 2021, with the exception of 2020 (the COVID year), we’ve continued on roughly 100% top line growth. It’s grown very, very quickly and very large in a short amount of time, at least to my experience of growing companies.

What is the best type of light for cannabis cultivation?

Cohen: It really depends on how you’re going to grow cannabis. There are a couple of different schools of thought out there. Number one is the traditionalists that you grow cannabis with the sun and as the sun goes, the plants go. And that’s one way to do it.

Then when you go inside and you want to grow it using artificial light, you can do it in a greenhouse, which is a big open glass structure flat. All the plants are on the same level and you’re using a mixture of sunlight and artificial lighting, usually LED lights.

And then there’s another way that’s becoming very, very popular now, which is vertical growing cannabis. Instead of going out left to right, you go straight up, and you could have two, three, four, or five levels of these big, huge racks. The lighting for the racks and the lighting for the greenhouse are very different because of the proximity of the light to the plant.

In a greenhouse, the light is much, much higher up in the air. By default, that is extremely powerful. The rack growing, the lights are right on top of the plant, usually six or seven inches, maybe even a little bit less. The intensity can’t be as much because it would kill the plant.

It’s difficult to answer that question, what’s the best type of light. I would say the best type of light generally is an LED light. You can get a lot more control with LEDs. You can change spectrums. You can manipulate the plant quite a bit more than you can with traditional light sources like high-pressure sodium (HPS). I would just say generally, an LED light, but then you get into the specific type of growing that you’re doing.

What kind of spectrum do LED lights use?

Cohen: You can come up with whatever spectrum you want. At Fluence, what we’ve done is we’ve pioneered the broad spectrum, which is a spectrum that exactly mimics the sun. And that was one of the things that Fluence really changed the game on.

Growing plants inside had historically been done with either high-pressure sodium lights, which are very yellowish in tint or LED lights that were kind of a mixture of blue, purple, and red. And those blue-purple-red lights are very, very difficult to work under. It’s extremely taxing on your eyes.

You can’t see without some kind of glasses like real close-up views of the plant if there’s bugs or mites or infestations or mold, and it’s just really difficult to work under. So, what Fluence did after a couple years of research has showed that the best way to grow this plant is by using broad spectrum, which looks white with some kind of red and green dots in it.

But if you look at the spectrum on a piece of paper, it’s almost exactly the spectrum of the sun. And what we found is that’s the most successful. We led the market with that in 2016 and 2017, and now virtually, every single lighting company out there is using broad spectrum.

I don’t know what the exact percentages are, but I would guess more than 75% of the people selling LED lights to grow cannabis are selling lights that are broad spectrum.

How did you research LED grow lights in the cannabis industry? What other research is your company working on related to cannabis cultivation?

Cohen: We do a ton of research, but basically, because we’re in Texas and we don’t have a license to grow cannabis, we’re highly dependent on partners. We have a wonderful working relationship with Texas Original Compassionate Cultivation, which is one of the three licensed cannabis growers in the state of Texas for medicinal.

We have a huge space in their grow where we are doing research around the clock on all types of spectrum and form factors and light intensities. And we also do this with a lot of our customers in states where it’s legal, such as in California, Michigan, and Massachusetts.

Even in Canada, we have R&D grow rooms at our customers’ sites that we run, but we’re running it under their license because we can’t run the product in Austin. We’re working with these customers to understand what the difference between different cannabis cultivars are and how light intensity impacts the growth of those cultivars.

[Note: It's not legal to grow cannabis in Texas without a medical license. Fluence's research team has partnered with one of the three licensed cannabis producers in Texas to study best practices in growing cannabis.]

For example, put it in vegetable terms, you have cherry tomatoes, beefsteak tomatoes, and Roma tomatoes. Those are just three types. Inside of those types, there’s hundreds of different cultivars. What we’re trying to do is find out how we can use our lights and change or manipulate the spectrum to impact specific events in a plant of a specific cultivar.

You’re really getting down into the subset of, now we have this one strain cultivar, how do I get this plant to grow either faster or more flower or higher THC, different cannabinoid profile? There’s a lot of things that you can manipulate in the plant by using lighting, but it really depends on what cultivar you’re using.

When you ask the question, what other research are we doing, we’re constantly researching the effect of various different types of spectrums on various different types of cultivars and trying to build a database of relationships between these. For example, let’s say 20 cultivars are most similar, they grow generally the same, but these 20 grow better. And that’s a metric where you have to decide what does grow better mean? Bigger, faster, more flower, higher THC under a different light spectrum? We’re finding that different spectrums affect different cultivars quite substantially.

If we have a customer that’s going to bring up a grow, let’s say, a million square feet of cannabis plants, which is a lot of plants. And we know what cultivars they’re going to be growing, specifically what strains, we can prescribe a lighting recipe that will maximize either their cycle times to grow, the plant biomass or, like I said, the different THC and cannabinoid profiles.

This is the part for me when I started to understand what type of research we were doing when I came to the company, I was fascinated. And We're doing the same thing in commercial agriculture. Not just cannabis. It’s very similar to figuring out how do I get this basil plant to grow fuller, but also to last longer on the shelf by two or three days?

Because if the basil grower—cannabis is a little bit different in this regard, but I’ll use this as an example because it’s a very good one—if the basil grower can guarantee the supermarket that you’re going to get four more days of shelf life off my product before it starts to wilt, they can get a higher price. Consequently, if the cannabis grower is growing the same strain as everybody else around them, but we can teach them how to get the THC 20% higher, or we can reduce 20% of the time it takes to grow, we can help them make more money. There’s a lot that goes into it, and it all starts, and it is driven by lighting, which kind of surprised me when I came in here.

Why are LED lights becoming the industry’s “go-to” in horticultural growing?

Cohen: There’s a number of different reasons. I have it from my perspective and there’s certainly the grower’s perspective, which is going to be a little bit different. Ultimately, you can control what you’re doing much more accurately using LED lights because you can tune them.

You can dim them, they can go higher intensity, lower intensity, you can have different spectrums. The traditional way to grow cannabis inside with high-pressure sodium lights, there’s one light, it’s one color, it is what it is, and you grow what you grow. But also with high-pressure sodium lights, really good growers will wind up changing the bulbs out because high-pressure sodium bulbs deteriorate very, very quickly.

Then you’re swapping bulbs out two or three times a year. What do you do with those bulbs? You throw them in the trash. They’re going to a landfill. LED lighting lasts 50,000 hours before it really starts to degrade, and that’s about 11 years. We have not yet gotten to the point where the lights that we’ve sold into the market are even close to being needed to be upgraded.

But what we can do when that time comes is we can save the light, take out the LED part of it, recycle that, and then put another LED in. You have a sustainability component; you have a control of your grow component. LED lighting has proven, by far over the last two or three years to grow healthier, fuller, higher THC plants than HPS.

And then lastly, you have electricity. And this is now becoming a bigger and bigger issue. We really struggled at the beginning to make the return on investment based on electricity, even though the LED lights consume about 40% less energy than a high-pressure sodium light does.

You’re literally saving 70% on your electric bill. But when this all started, electricity rates in the United States and Canada were very, very low, four or five cents a kilowatt hour. You needed a lot of kilowatt hours to make that back. But what’s happening now with the kind of global supply chain shortage and the price of oil going up and the price of electricity going up, that is now becoming a much, much bigger factor. So much so that we have customers that are growing under traditional high-pressure sodium lights that have stopped growing because their electricity bills are killing their profits. And now they’re really stuck. Do they go out and spend the money on LED lighting to get a lower electricity bill or do they wait for the cost of electricity to come down? I would say there’s three big things that make kind of LED lighting the go-to: control, sustainability, and electric consumption.

Can you tell us about some of the results you found in the Cannabis Business Times “2021 ‘State of the Cannabis Lighting Market’” report?

Cohen: I think the most important takeaway for us is that LED adoption is on the rise. We’ve modeled this thing. We do it every year. We sit down and do a lot of market modeling around the world, and we still can’t believe that these adoption numbers are as high as they are.

We had it about 20% less. LED usage for cannabis cultivation is up more than 45% for all stages of plant growth since the first report in 2016. A majority of about 60% of those growers that we speak to that aren’t using LEDs during flowering are considering doing it in the next six months.

That data says this is still growing very quickly and very closely emulates what we’re seeing from a customer count revenue and overall growth of the company. It’s really great to see that it’s being adopted so much. When I first came in 2018, there were a lot of concerns about the reliability of LED lighting. And the experience that people had had in the past was buying cheaper LED lights or stuff that was made in Asia. Then there were problems with the power, and a lot of fixtures catch on fire if you don’t build these things right. LED lighting got a real bad reputation in growing plants for a long time.

With that, I think it’s just about gone. In 2018 and 2019, the kind of the tide came in of LED lighting and from 2019 to now, it’s what people talk about when they build to grow. Can I afford to use LED lights or not? Because the important part is that a high-pressure sodium light is about $250 where an LED light is like $800 or $900.

You have a pretty staggering difference in cost, but the electricity difference alone is a huge number. And then if you talk about LED lightings are more efficient and you can grow one more full cycle of plants in a year. I mean, if you’re pulling down a 10,000-plant crop and you can grow 10,000 more plants in a year, that’s a direct hit to your bottom line. It’s really what growers are paying attention to.

I would use the word astronomical. I can’t believe it is taking on so quickly and so much. And because you also have a lot of these growers, we’ll talk about these people. These are people that most of them were growing illicitly for a long time. They have small growers in either their house or their basement or their backyard.

You get into a large-scale commercial grow with 10,000 plants, there’s not very many people in the world who have 5- or 10-years’ experience with that. And having a reduction in the amount of variability is always going to be better when you’re taking on something that big. That’s exactly what LED lighting does. It allows you to control the variables a lot easier.

What is the difference between the three different types of lighting?

Cohen: So, we’re talking about differences between LED, high-pressure sodium, and metal-halide lighting. The primary difference is that an LED light is a solid-state electronic circuit. It’s as much a computer as anything else. LEDs are simply diodes. And diodes are in computers, and they heat up and there’s a treatment of either phosphorus or something on top of the LED that makes the heat transfer into this phosphor and generates the color.

High-pressure sodium lights and metal-halide are your typical light bulb type of light. You plug it in, it works for a certain amount of time. The energy that the light creates only about 30–40% of it goes to the plant, the rest of it comes off in wasted heat, so it’s a very inefficient source and you can’t control them, you can’t dim them, you can’t tune them, you only turn them on. The one good thing about them is they’re extremely predictable and reliable, and they’re very cheap. But there’s a lot of countries in the world that are moving to ban this type of lighting because once the lighting is done, you can’t dispose of these bulbs in a safe manner. It goes into the ground. Metal-halide bulbs, some of them have mercury in them; high-pressure sodium, the bulbs filter sodium, and you don’t want that stuff in a landfill. That would be, in my view, the three different types of lighting.

What is high lighting intensity?

Cohen: When we talk about high lighting intensity, we’re talking about increasing the number of photons that come out of the light and hit the plant. In every area of LED or any kind of lighting, when you’re talking about lighting up areas or rooms or streets or roads, you talk about lumens and the intensity of the light and how bright it is.

Plants don’t know brightness or intensity necessarily. They know photons. When we talk about high intensity lighting, what we’re referring to is a much higher photon producing light and that is bigger, better LEDs, more LEDs. And there’s a wide, wide range of how many photons you can make come out of a light.

There are 1000 photons, 1500, we call it PPFD, which is photosynthetic photon flux density (PPFD). The acronym PPFD is an indicator of how many photons are coming out of the light being delivered to a crop which enables photosynthesis. And on high intensity lighting, what we’re trying to do is hit the cannabis plant with as much light as it can possibly take and see what the breaking point is.

So, what our research over the last year or two has found that you can go a lot higher in photons that are hitting the plant lighting intensity than anybody ever believed. You have to feed the plants differently. You have to water them differently. You have to care for them differently. But you can actually grow them much more efficiently with a higher number of photons coming up.

What advice do you have for beginner and more experienced growers that are looking for the right lighting and growing methods?

Cohen: My personal advice, I’m not a grower, but what I’ve seen over the last three years is start small. Come up with what your endgame is for your grow, whether it’s 5 plants, 50 plants, 5000 plants, 50,000 plants, and try to recreate a very small replica of what you think you’re going to do, and then scale that slowly.

Almost every grow that we’ve seen, where they start, where they try to go from zero to 1000 right away is we see lots and lots of problems in scaling. Everything from disease on the plants to different temperatures in different rooms that affect the output. My advice for beginners, it would be, good for you. If you want to grow cannabis, that’s great. Start slow, start small, and really learn what the different variables are that affect the plant. Even for more experienced growers, I would say the same thing. If you go too fast too soon without proving it out, the cost is really bad to lose a crop or to lose a cycle of plants. My advice, and I think all of our growers that we have on staff would agree, is to start small, prove out the concept, and then scale it slowly.

And remember, plants are living things. If the plants have some underlying disease or defect in them and you put that one plant in a room of a thousand other plants, you’re going to have a thousand plants that are infected in the same way. And you don’t know it until the plants grow and you’ve put in all the time and energy into it, and then you go to harvest it and you realize you have a mess on your hands.

The most successful growers I’ve seen have taken whatever they want to do, done it at like a 10% scale, then a 30% scale, then maybe 50%, and just keep slowly expanding. Even though there’s a lot of pressure to grow the plants because the cannabis is $2000, $3000, $4000, or $5000 a pound, so you think “I can make all this money.” I believe you’ve got to go slow. That’s my advice.

How can growers compliment their lighting strategy with expert data measurement tactics?

Cohen: That’s a good question and it’s kind of the newest hottest thing that’s coming. Our lights have Bluetooth mesh system in them. A lot of our competitors do the same way. The light interacts with whatever sensors are in the grow, and we don’t make the sensors, but our lights can read the data from the sensors. It takes that data and sends it to a processing platform that then tells the grower, “In quadrant five, you have a mildew. In quadrant four of your grow, you need to add more water. The airflow in this area isn’t right.” These sensors are producing all kinds of data on a regular basis.

And what the light does is act kind of like the Trojan horse. It takes all this data inside because the light is a small computer. It processes it and it sends a signal to the grower on what to do. And many times, the signal is to do something with the lights. The interaction between lighting intensity, lighting uniformity, and spectrum can be manipulated once you get all this data that a lot of the great growers will do.

These are people that before the sensors were available, I know some of these people, they had thousand column spreadsheets and they were literally measuring every little thing in the grow. Now you can do that much more efficiently and much faster, so much so that there’s some grows now that are—you close the doors and you just read your iPad and it says, “Add more water,” and you press a button and the system waters.

It’s changing as we speak. That data measurement and analysis technology, even AI a little bit to say that the computers are learning how to grow better plants, that’s just happening now.

You see this a lot of the vertical growers, not cannabis, let’s call, the Boweries, the AeroFarms of the world that have these massive indoor vertical lettuce grows. What they’re trying to do is learn by sensing everything possible and then having an AI system crunch that data and say, “Okay. This is the most efficient way, manage the variables this way.” It’s all very, very interesting.

How are implementation of vertical racks increasing vegetation and flowering?

Cohen: Well, that goes back to what we were saying earlier about the different ways you can grow it. We see the most successful growers and we define successful by the best quality product and the most efficiently grown, growing in vertical racks. A big, open, single-level space like a greenhouse is one way to use space but controlling what’s going on is much different.

The customers of ours and the real great growers who go vertical, what they’ll do is they’ll take an old, abandoned warehouse and they’ll build 10, 20, or 30 rooms. They’ll only put 300 or 400 plants per room, but they’ll go straight up. It’ll be five or six racks, four or five levels high, and they keep things very, very controlled.

By going up in a room, you can utilize the space a little bit better. And then at the end of the day, if you have any issues in one of your rooms, as long as you control everything, you would only lose that room or plants in that room versus if you have a disease outbreak in a greenhouse, it’s going to spread right across all of the plants almost instantaneously.

This lighting strategy of being able to grow multiple cultivars, multiple different strains by simply separating them into different rooms or on different levels of the rack gives the grower a lot more flexibility.

Do you see any other kinds of lights or growing methods looking to become more popular than LED lights?

Cohen: I see different growing methodologies starting to come into the market, like growing in containers, like growing in pods, but all of these use LED lights. If I was just to strictly stick to the delivery of photons to the plant, I don’t know that there’s any better way to do it right now.

If you can’t do it with the sun and you don’t live in Humboldt County in California, LED lighting is the best way to go. And so far, I haven’t seen any other technology that is poised to change that in the near future.

Do the different state-by-state cannabis regulations affect the research of your report?

Cohen: I don’t know that a variability from one state to the next affects the way we do our research. There could be local regulations in one state versus another, which dictate how many plants you can use for research or what type of research you can do. I’m not aware of that, but that’s entirely possible because there is a lot of variability from state to state.

But what we basically do is we sit down once a year. We have a strategic planning session for our research team and say, “What do we want to figure out this year? What’s our plan?” And we list dozens and dozens of variables, and we try to chop that down to something that’s a little bit more manageable.

We put a price tag on it and say, “Okay. We’re going to commit X amount to research next year by doing these 5–10 things.” Once we identify that, that’s when we go out to our customers and see which customers are best positioned to do the different type of research we want to do.

Is there anything else you would like to add?

Cohen: Yeah, I would. First of all, thank you very much for the time and giving me the opportunity to speak. This is extremely exciting. The industry is growing up. I told a story yesterday. It’s like a five-year-old kid growing into an adult in like 18 months. And those growing pains, pun intended, are coming through now across the industry.

You have a ton of money that came into it. You’ve got a lot of people that started up growers that got licenses that have now learned the hard way that it’s not a matter of just dropping a couple of seeds in a pot of dirt. And the knowledge transfer that’s happening now and the efficiencies that are starting to be gained in the industry are incredible to watch.

I can only imagine that it was like this in any other rapidly adopting technology. The first year or two, people are learning, the next couple of years, you’re getting better at it. We’re almost getting to the point where it’s now becoming something that’s being perfected.

And it’s really impressive to see the difference between the people who get it and understand how to continually get better, and the people who got into it because either they just want to be around a ton of cannabis, or they think they’re going to get rich. It’s difficult. It’s really difficult. But it’s been amazing to watch the cream of the crop of the growers really rise above everything else and see the real difference that they can make in growing their plants the way they grow them versus everybody else. It’s been a great ride, really exciting!

Editor’s note: This interview was conducted in November 2021 and published prior to the announcement in December 2021 that ams OSRAM has entered into a definitive agreement to sell Fluence to Signify. Per the release, the acquisition is expected to close in the first half of 2022, subject to standard regulatory approvals and other conditions.

How to Cite This Article:

M. Colli, Cannabis Science and Technology® Vol. 5(4), 16-23 (2022).