Precision Photon Delivery Systems with Dr Bruce Bugbee and Dr Marc van Iersel

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BRUCE: I'm Bruce Bugbee, President of Apogee Instruments,  and professor at Utah State University.   We're honored today to have my colleague,  my long-term colleague, Marc van Iersel,  here with us at the Apogee recording studio, both  to visit at my laboratory at the university to   talk about science, but also to talk about  commercial implications of all that science. Marc and I have been colleagues for  many, many years, many decades even,   and we've shared students back and forth. It's  been a wonderful collaboration. The thing we   want to talk about today is exemplified here on  the board, what we call precision photon delivery.

So now that we live in an era with LEDs,  wow they give us unprecedented ability   to control the delivery of photons, and not  just focused photons, but changes in timing   of the photon delivery. So in this case, when we  say precision delivery, today we're going   to mostly talk about precision delivery in time  of these photons. So Marc, do you want to start by   how your university research has informed this  and how has that led to your--Marc has a company   called Candidus that makes software and hardware  to achieve precision photon delivery. So he's right   in the middle of all of this, but do you want  to comment on how your university research has   informed all this? MARC: Yeah, absolutely, and thank you  for having me today, Bruce. So I started working on  

lighting research about eight years  ago. And when I decided to do so, what I  identified as a niche that nobody else seemed to  be paying attention to was how can we actually   control LED light fixtures very precisely to give  plants the amount of light that they need at the time   that they need it and can use it most efficiently. So that's how we started out, since then we have   gotten a big USDA grant, where we are collaborating  with Bruce's Utah State University lab, but we're   also collaborating with fantastic electrical  engineers and people in energy informatics   who have helped me see the bigger picture  of how you can actually do this. How you can   optimize lighting and how this can impact  society at large, which ultimately makes all   of this work much more exciting. So it's been a  fascinating evolution over the past eight years,   where I've learned lots of things from working  with lots of people who know things that I do not.

BRUCE: Just to elaborate on that  for our for the listeners, it's  probably close to five years ago now we've  collaborated on a large grant to the USDA to look at optimizing lighting. And this LAMP--this project came to be called the LAMP project--and I think you're the one  that coined that phrase L-A-M-P   Lighting Approaches to Maximize Profits. And,  of course, the USDA is very interested in optimizing this and the whole thing  is lighting approaches. So now with  

USDA funds and collaboration of multiple  laboratories, we've done a lot with this.   MARC: Yeah it's been a great project. It's  not just plant scientists that are involved.   So I think the key word, actually, in the title of  the project is "profits," and when we think profits,   we have to think economics, right? Because Bruce and  I typically really tend to focus on the plants: how   do we grow plants? And that's really fascinating  stuff, but if we don't take into account the cost   associated with that, then ultimately we're not  serving the controlled environment agriculture   industry--plant factories and greenhouses--in the way that we need to, because yes, they   need to grow plants, but more than that what  they have to do is be as profitable as  they can be. And that has really required  this interdisciplinary work to get these   different perspectives on how we can do things  beyond just plant science and horticulture.

BRUCE: Yeah, in this grant we all joke, because the currency  for us as professors is a bunch of referee journal   articles, which as you know can be pretty egghead  journal articles. And the USDA doesn't want to see   a bunch of egghead referee journal articles,  they want to see boots on the ground. They want to see how all of this work is  going to help growers. MARC: Yeah, and that is actually   where my company can also play an important role.  So as academics, we can develop all these methods. We try them on a relatively small scale, but as  academics we have relatively little incentive   from our institutions to try to make sure that  these new technologies actually get implemented   at scale throughout the industry. So at  Candidus, we are very focused, of course,

in making sure that we get this technology into  commercial facilities. And we have an additional   project with a different branch of the USDA, the  National Resources Conservation Service,   where Candidus works with them on not just  showing that we can achieve significant energy   reductions through better lighting control methods,  but what we really are focused on there in the   long term is to develop guidelines to invent incentive or rebate programs   for the industry to help them get this technology  into their greenhouses. And so I think that is a   really exciting long-term thing, because those  incentive programs are going to really help make   this technology accessible. And certain utility  companies, especially in the northeast of the U.S.,  

are already providing rebates, not just for better  lights, but for better lighting control   systems. So we really see this movement happening,  and that's a great impact of project LAMP. BRUCE: And I think most people know now that every  passing year there are fewer and fewer high   pressure sodium lamps used and more and more LEDs  used, as the LEDs get both more reliable and more   cost effective. And, of course, it's a nice  synergism between us, because, first-of-all,   you've got to precisely measure the photons and  then you use the software to figure out how to   deliver the photons. MARC: Yeah, and the change from high  pressure sodium fixtures to LED fixtures  is really important when you think about  controlling lighting. With high pressure sodium   maybe you have some ability to dim them, depending  on what fixtures you're using, but once they take   some time to heat up and give you full light  output. Once you turn them off, they need time  

to cool down before you can turn them back on. So  you can't get real precise control over how much   supplemental light you're providing in a  greenhouse. With LED fixtures, almost all of those   are fully dimmable at this point in time. And  their mobility allows us to very precisely control   exactly how much supplemental light we provide  in response to how much sunlight is available at   that particular point in time. So LEDs have really  opened up a whole new area to make this lighting  

control much more beneficial for the industry. BRUCE: Yeah,  all of us at our research greenhouses were pushing   the envelope with high pressure sodium trying to  cycle them faster to get this variable control,   and we burned up a lot of capacitors and a lot of  high pressure sodium lights trying to push them   to the edge. And that was expensive  having to rebuild these lights all the time.   This is something that people don't  think about much with LEDs. They think, "Okay,   great, they're more efficient, but man, they're  so much more controllable." We're just on the   threshold of taking advantage of that. MARC: Yeah, I  really think that it is the next frontier and  

when I would talk to the industry about this  topic two or three years ago, people would go,   "That's pretty interesting, I never thought about  this." But I was at a trade show just two months ago,  and it's really satisfying to see that we have to  explain much less what we're doing, because people   are getting the concept. And I think when it comes  to lighting, control of how many photons we deliver   when is really the next frontier. LED fixtures  are great, but they're starting to push to the   theoretical limit of how good they can be. And  advances in the efficacy of LED fixtures, they're   going to slow down, but we can still make big  improvements on actually how we use those fixtures   in commercial facilities, and  the research facilities, as well.  

BRUCE: An analogy, I guess as teachers were always trying  to think of analogies that help explain things, but an   analogy for me is being like a high performance  athlete where when you eat and what you eat   makes a big difference in your performance. And  here with the HPS, well, you can   have a steak dinner or not a steak dinner. And  now we could have almost the equivalent of like   precision intravenous feeding to deliver  the photons at just the right time for maximum   performance. MARC: Yeah, and that's absolutely correct. There are really good quantum sensors available,   of course, including from Apogee. That information  is really critical, but you can interface those   with really cheap microcomputers that can take  those readings, apply really advanced algorithms   to that real-time data that feeds in, and then  those microcomputers can send a signal back to   the light fixtures and tell those light fixtures  exactly what they need to do. And at Candidus, we tell light fixtures every 15 seconds what change  we want to make to make sure that by the end of   the day, or by the end of the growing cycle, that  crop has received just enough light to grow exactly   how it needs to grow, but without  providing more light than is really required. 

And that excess light that is often provided in  greenhouses is really expensive. And in some cases,  I think that can make the difference between a  greenhouse being profitable versus losing money.   And so we really want to push those  facilities towards profitability.   BRUCE: It's pretty intuitive on a partly cloudy day.  When the sun comes out you can turn your lights  

down because you get sunlight, but five minutes  later the sun goes behind a cloud and now you need to   turn them back up. And, of course, this is what we're  talking about--that level of controllability.   First-of-all, Marc just gave an invited  talk at a controlled environments conference.   It was a conference in Tucson that we both  were at. But he gave a talk about this and   I wonder if you could elaborate a  bit more on the variable price of electricity   and how that enters into this. MARC: Yeah, I think that  is a really fascinating topic. And the reason   that we are working on this topic at the  University of Georgia is because I have   colleagues in engineering and energy informatics  who understand these things much better   than I do. But it seems pretty intuitive that  if you have variable electricity prices over   the course of a day, you want to provide  as much supplemental light as possible   during times of the day that that  electricity is relatively cheap.  

And so my colleagues in engineering have  developed algorithms that can take advantage   of that variable electricity price. And now the  goal is no longer to minimize the amount of   supplemental light that we provide to meet a crop's need, and that's what I did in the past. We are now able to actually control lights  based on how can we minimize the cost of that   electricity. And, of course, when you think about  that from a commercial perspective, that is really  

what they need to do. And so we have developed  algorithms that can do this really well and   those algorithms reduce the cost of electricity  use by about 35% over less sophisticated   methods that are actually probably still better  than what is commonly used in the industry. Likewise, at Candidus we have done a number  of trials in commercial greenhouses with our   proprietary lighting control approach. And we  typically reduce electricity use by about 30%   without a notable impact on the crop--  the plants grow just as well. But that is a lot  

of money that you end up saving because the cost  of providing supplemental light in the greenhouse   can easily be $60,000, $70,000 per acre over a lettuce growing cycle. So   if you can cut that by about a third, that's.  in my book. quite a bit of money. BRUCE: Yeah. Not everybody understands the issues of variable  electricity pricing, other than we know they often vary. But when a utility company  gets the infrastructure to provide electricity,   if you if they don't use it, it's hard to store  electricity. And so they end up purchasing   electricity that they can't use certain times  of the day and they would love to have customers   use that surplus electricity. And then the  opposite, the common thing is late in the afternoon  

everybody's air conditioners come on and now  the cost of electricity is just enormous. Well, we could just turn the lights off during those  periods of peak demand. So this interface between   big greenhouse growers and utility companies has  a lot of potential to help the utility companies   efficiently utilize their capacity. MARC: Yeah,  and what we have actually seen in the past weeks   in the United States is that people in California  have been asked to turn up their air conditioning   units or turn up the ac to maybe 78 degrees. Texas has massive problems with the   utility network not being able to provide enough  power for all of their customers during peak times.  

And so, actually, at Candidus we have collaborated  quite a bit with utility companies to try to help   them shift the electricity-using greenhouses  away from those peak hours. And this is a really   important topic for utility companies and that's  why i think ultimately we need to get the control   environment ag industry hooked up with the utility  industry, so that we can come up with solutions   that are actually beneficial for everybody. And  then hopefully we can have a positive impact   on society, as well. So we're really focused  on creating a win-win-win scenario there.  BRUCE: So if you tell people, "Just suffer. Turn your AC up,"  they're not very happy about that. But   we don't usually consider if the plants get happy  or sad. If we just tell them we're going to give   you the photons a little later, the plants grow  just as well. And that's the issue here.

MARC: That's actually an interesting topic  because the conventional wisdom and what we   tend to do in controlled environment agriculture is  we want to control everything really precisely.   I think those of us who are working in controlled  environment agriculture we tend to be, as I like   to say, control freaks. But we've actually done  quite a bit of research at the university that   has shown that plants actually don't really care  about that precision control. They're perfectly   happy if you give them more light now, less light,  later maybe more light today, less light tomorrow.  

And that, first-of-all, was really surprising  to us, but it was also really exciting   because that now allows us to really take  advantage of time periods that electricity   is relatively cheap. And it's provided a whole  new frontier for this precision photon delivery,   because we don't have to keep the light levels  in the greenhouse as stable as we possibly can. So that can be really beneficial for the industry.  BRUCE: So just to switch topics a little bit, I want to   ask you about how did you choose the name Candidus for your company? People ask me how did you choose   Apogee? Well, it's the point in an orbit farthest  from the earth, and I was doing a lot of work with   NASA, so that was kind of a no-brainer, but  Candidus, that's an unusual name. How did you   come up with that? MARC: It's kind of an interesting and  maybe funny story. So my co-founder, Erico Mattos,   asked me if I was willing to co-found a company  with him to work on lighting control systems. And  

I said, "Yes, I'd be excited to work on  that." And, of course, the very first thing we   needed to do was figure out, well, what is the name  of that company going to be? So I spent an evening   on the internet and I was interested in either  Greek or Latin words that had some connection   to light, because our focus, of course, is on  light. And so I found all kinds of terms, but   most of those were already in use by lots of other  companies. And I finally came across Candidus,   and one of the meanings in Latin is "light," but  another meaning that pushed it over the edge is   "grey-haired." And I said, "That's it! That's what we're  going with!" I sent an email to Erico. I explained it. He laughed and agreed, and here we are. BRUCE: Here we go.  MARC: So I'm the official spokesperson for the company.  

BRUCE: Wise elders helping you better utilize your  photons. Well, Marc, it's been a great great run that   we've had back and forth over the years and it's  so exciting to be working in an area that   has both lots of opportunities, profound scientific  discoveries, but the commercial opportunities, too.   They're very synergistic for both of us.   MARC: Yeah, as you well know, it's really exciting if  you can take the work that you do at a university   and through a company really help to to scale  the work that we do in an academic setting. And  

there are lots of things in my career that have  been rewarding. Perhaps the most important thing is   all the people that I've worked with, the graduate  students that I have trained. But I think now   seeing this technology spread through the industry, that is really rewarding in a different way   because I can tell that we're making a positive  impact. Not just on the industry, but I think we're   having a positive impact on society, too. So  it's really exciting to be involved. BRUCE: This meeting--   it was just last week that we were together in  Tucson. It's a controlled environments conference.   And when that first started long time ago back,  when we were much younger, it was a bunch of   academics sitting around a small table discussing  science. And that was the whole meeting. And as the  

basic science found application, commercial people  started to want to come to the meeting. And sure,   come to the meeting. And the group grew, and it grew,  and it grew. And the growth chamber people come,   lots of LED people come to this, instrument  companies come to this meeting now. And so   now we had over 200 people at our last meeting,  which started out with a bunch of egghead people   discussing some pretty refined points of science.  It's just a remarkable transformation. MARC: Yeah, well, as   you commented on during that meeting, well  you've probably been part of it for about 30   maybe a little bit longer years. BRUCE: Yeah, over 30, yeah. MARC: And controlled environment was really just a   research tool, where we could do research that then  might or might not have practical applications. A  

lot of it was pretty basic research that was done  in growth chambers basically, but maybe nothing   about controlled environment. That is a very large  controlled environment agriculture industry. We   have a number of large vertical farms and they  keep growing. And on the greenhouse side, the   greenhouse vegetable industry is just exploding.  So, I think that is at least to some extent really   a long-term result of the work that people like  you were doing 30 years ago already. And now we see  

a real transformation of how we actually grow  vegetables. BRUCE: The earliest stuff was mostly NASA   funded. We got NASA funding and NASA can't  really have a greenhouse on the moon or   Mars. There's no atmosphere. It has to be pressurized  or meteorites would break it. NASA has   to use electric lights in a closed system. And  those are the early days, but boy, as soon   as LEDs came along, it just exploded for commercial opportunities. MARC: Now, though, I remember  

some of the first thoughts at this very meeting  about growing plants under LEDs and it was really   interesting. You saw beautiful pictures, but only  NASA could actually afford to buy LEDs because   they were so expensive, and, quite frankly, they  were very, very bad compared to what we have now.   And for a long time I was not convinced that  this would be something that would ever become   commercially viable. But, of course, by now  it has completely changed and LEDs are  

really efficient. There's probably never going to be  a different kind of light that is going to come   along that is going to replace LEDs, because  LEDs are so good and they will be the choice   for growing plants, whether it's indoors or in  greenhouses. BRUCE: Well, we both talk about this   all the time, but if we look at the history of  electric lighting, if we go back far enough it   was monks with kerosene lamps walking from room  to room. What's the energy efficiency of that? It's   teeny, it's tenths of a percent turning  energy into light. And then Edison invents the   incandescent bulb and it's a huge breakthrough,  and we got up to like 5% efficiency.  And at the time, massive breakthrough. Then  after World War II we went to fluorescence  

and we got into the 15% efficiency with fluorescent  lights--another big breakthrough. Then we went to   high intensity discharge--high pressure sodium. Another big breakthrough, we got into the 30%   efficiency of electric lighting and we thought, "Oh my, this is incredible!" Guess what? Now we are at   LEDs that are 80% efficient. That's why it's  the end of the road. You can't get past 100 and the   LEDs are going to creep up toward 100. It's  just amazing. MARC: Yeah, theoretically LEDs can become  

100 efficient. I will never get to 100, but at some  point we'll be at 95 efficiency. And that's why I   think it's pretty easy to predict that there's  not going to be something else that comes along   that is going to be even better than LEDs. BRUCE: Yeah,  we talk a lot about the light to heat ratios of   things and light is good, heat is bad. Then LEDs, interestingly enough, when you calculate the   light to heat ratio of sunlight--the energy in  the photons versus the total energy of the sun--   you get about two micromoles per joule from the  sunlight. And this is the photosynthetic photon   flux divided by total energy. And LEDs, now, we're  past three micromoles per joule. It's amazing.   LEDs have caught up and passed the sun for  efficiency. MARC: That's the fun stat. I've never really  

thought about the efficiency of the sun, but that  makes sense and it is a really good indication   of how good these LEDs are now. And then the other  exciting thing, of course, is that with these LEDs,   unlike the high intensity discharge lights, we  can get that precision control. That was never   going to be possible with HID lights, so it's not  just the efficiency, it's also the controllability   of these LED fixtures that is going to be  really beneficial. When you think about commercial   buildings, in many cases, those lights are already  dimming automatically in response to how much   light is coming into the building. You don't notice  it because it is gradual and your eyes adjust to   it, but it is one other way in which we can use  these LEDs to be really energy efficient. BRUCE: Yup, well,   that's why we wanted to have this discussion about  precision timing of delivery, because when people   think about LEDs they're all about, "Okay, what's  the optimum spectra and what color should I use?"   That's a huge subject, which we've  talked about many times. But in addition to  

that, there's this timing of delivery, which  is great. It's a new frontier.  MARC: And I think that's going to be the next big  advance in lighting control--in controlled   environment agriculture. And it is really  important. You think about it, it's obvious   in greenhouses where you have the sunlight that is  constantly changing. When you think about a plant   factory where the cost of electricity is an even  bigger part of the overall production cost, right?   If they can respond to those real-time  pricing changes that are happening, they   could substantially reduce electricity cost. That  is going to require collaboration, I think, between   utility companies and those plant factories,  because, I think, utility companies are going   to have to provide incentives for vertical  farming companies to implement some of that   better approach that can help the utility  companies in a big time. BRUCE: Yeah, you know one of the   things that comes to mind for greenhouses, as you  mentioned recently. If you run your lights late at  

night, people complain about the light pollution.  Well, so shift it. So, let's turn them on early   in the morning and off earlier. Then people don't  complain about light pollution if the lights come   on at 4 AM. But boy, if they don't go off  till 10 PM, there's a lot of heartburn about that.  So shift it. The plants are fine doing something simple like that.  MARC: Yeah, it's simple for a greenhouse to just shift that light . It actually creates some interesting challenges   from a control perspective, because if we provide  a lot of light later in the day, we have already   measured how much sunlight that greenhouse got  during the day. And so we know exactly how much  

more light we need to provide during that evening.  The challenge is, if we provide light early in the   morning, we don't know how much light those  plants are going to get later in the day.   And so another thing that we need to incorporate,  I think, in these lighting control algorithms is   forecast of how much solar radiation, or how much  light, is going to be available during the day. And   then we can start taking that into account at 3AM  when there is no sunlight yet. And luckily enough,  

those forecasts are readily available because the  photovoltaic, or solar energy, industry is heavily   dependent on those forecasts, so that can simply be  purchased from a variety of companies. That's   the next thing that we want to look at. BRUCE: Yeah. Yeah,  though that's a really good point. As we do more   solar PV, this forecasting it's super important  for them, too, to match supply with demand.  

MARC: We're just lucky that that industry is so dependent on  that forecasting, because if it was just the   greenhouse industry, I don't think anyone would  bother actually developing these forecasts.   BRUCE: Yeah. MARC: But they're readily available  and we can take advantage of them.   BRUCE:, Well, thanks. This has been a great discussion. As  we always say, stay tuned! This is a evolving thing.   We keep getting new research data. Things change.  We're always looking for ways to explain the basic  science and find ways to use the basic science to   commercialize it and help a lot of  people. MARC: Well, thank you, Bruce, for having me   and thank you for watching our conversation  today. BRUCE: Stay tuned, we'll be in touch. Bye, now.

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2022-09-26

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