L.E.D.

by Bob Johnstone

  Like Valoya, PhytoLux started out using a combination of red and blue LEDs. When blended they produced a distinctive magenta-tinged glow. The red-blue ratio could be altered to produce different responses in crops. But Edwards could not help wondering about the other colors found in daylight. As an engineer he was unwilling to believe that plants were simply rejecting these colors; they had to be using them in some way. Was it possible to use other wavelengths - like green and amber - to manipulate plant response? PhytoLux was running trials to find out. The firm’s researchers also experimented with adding some ultraviolet and infrared. Was it the energy of the photons that was making a difference? “It’s an area that we’re only really beginning to get to grips with,” Edwards told me.

  Startups needed some sort of edge if they were to compete with the 500-pound gorilla in the greenhouse — Philips. The giant Dutch firm had not been slow to grasp the potential for LED lights in growing plants. Especially since it had the advantage of being based in Holland, where the horticultural industry is huge. Dutch growers boast that they have over 60 square kilometers of crops under glass. They dominate worldwide trade in flowers (not just tulips), with a 44 percent share. The Dutch are also the world’s largest exporters of tomatoes. But big though it was, Philips could not be everywhere at once. The firm chose to concentrate initially on tomatoes, where it had proven that its LED technology improved yields and produced consistently tasty fruit all year round. Though he recognized that Philips was a formidable competitor, Edwards also applauded the company for establishing credibility that smaller firms could exploit. “Without what Philips have done, the industry wouldn’t even be considering LED lighting for horticulture,” he said.34

  Western Europe accounts for almost seventy percent of the horticultural lighting market. In the US, which relies heavily on Mexico to provide consumers with fresh fruit and vegetables, there was less incentive for growers to invest in artificial lighting. With the exception, that is, of one, very high-value indoor crop: cannabis. The legalization of recreational marijuana in eight US states sparked a gold-rush as new entrants flocked to stake their claims. In addition to the historical need for concealment, raising plants indoors had also given cannabis growers the ability to control every aspect of the environment. Lighting in particular was crucial. Growers used both types of legacy lights: blue-tinted metal halides for the leaf-growing stage, orange-tinted high-pressure sodium for stimulating the plants to flower. Such lights were heavy, requiring supports to hang, and they reduced in brightness every year so had to be replaced often. But the biggest problem was the heat that the big lights generated turned grow-rooms into ovens, obliging growers to run fans and air conditioners to circulate and cool the sweltering air. This devoured electricity.

  In the past energy costs had been almost irrelevant to marijuana growers. Often they would simply siphon power off the grid illegally. Now, the huge increase in production threatened to outstrip the supply of available energy. In Washington State alone the cannabis canopy covered over 12 million square feet. To grow that much weed took massive amounts of electricity, the equivalent of powering 600,000 homes. Alarmed at the prospect of enormous increases in load and anxious to avoid blown transformers and blackouts, utilities had begun offering rebates to persuade growers to switch to more energy-efficient technologies, in particular solid-state lighting. LEDs could be several times more expensive than legacy lights. But initial cost was less of a deterrent in an industry where profit margins were high. Some marijuana growers could be just as conservative as their counterparts in the fruit and vegetable industry, preferring to stick to their tried-and-true methods. But there were plenty of others who were open to trying new things.

  34 In April 2016 PhytoLux signed a licensing agreement with Plessey, a leading UK semiconductor maker, under which the startup essentially became a division of the larger firm. In January 2017 Steve Edwards left Plessey to work as a consultant.

  “The difference with the marijuana growers is that they’re very much prepared to experiment,” Edwards said. “Particularly because their crop is high value, so the cost of experimenting is much easier for them, they can recover their money very quickly.” A further attraction was the ability to tailor the spectrum to produce the desired outcomes. By manipulating light recipes to mimic conditions found in countries where cannabis is native, growers could shorten the time it took plants to flower by as much as two weeks. They could even alter the balance of bio-active cannabinoids, lowering the anxiety-inducing THC content and increasing the therapeutic ingredient CBD. Though cannabis represented perhaps five percent of total US protected crop growing, it demonstrated that the new technology of LED could make a difference. That in turn was making commercial food growers sit up and take notice.

  If strawberries at Christmas and customized cannabis were the present for horticultural lighting, what was the future? That was what Cary Eskow, illumineer-in-chief at distributor Avnet, whom we last met in Chapter Ten, wanted to know. Eskow’s quest was always to get ahead of the curve, then disseminate what he had discovered. Around 2010 he became intrigued by the potential for LEDs to grow plants. This seemed to go well beyond simple photosynthesis. The scientific papers he read speculated that one of the ways plants know they are near other plants is that they selectively reflect certain wavelengths. By fooling a plant into thinking that it was close to its neighbors, you could change the way it grew. This was fascinating stuff, but was it true? To find out, Eskow had one of Avnet’s labs in Phoenix retooled to investigate plant leaf reflection. Another topic that beguiled him was the potential to use ultraviolet light to grow healthier vegetables, sometimes also known as “superfoods.” Mushrooms, for example, don’t need much light to grow, they are generally cultivated in the dark. “Just a short burst of UV-B increases the vitamin D content in the fungus from next to nothing to four or five times the recommended daily dosage,” Eskow explained. “That stays in the plant after it has been harvested, giving farmers an opportunity to increase the cash value of their crop.” It might even be possible, he speculated, to use solid-state light to do “pharming.” That is, harvesting pharmaceuticals like anticarcinogens from genetically-modified plants. Another possibility was manipulating light to alter a plant’s response to pathogens.

  In 2016, encouraged by the success of his initial lab experiments, Eskow decided to go one step further. He would show the lighting community (and others) what could be done using an array of the latest technologies. In his garage at home Eskow built a scale-model greenhouse. It was about the size of a tea-chest and topped by a gable roof. Equipped with tuneable LED lights the perspex box possessed the ability, not just to provide energy to plants through photosynthesis, but also to change their growing characteristics through photomorphogenesis. The model bristled with sensors. They monitored the amount of light and carbon dioxide the plants absorbed; also, the spectral content of light from the sun and how it changed over the course of a day. Output from the sensors could be sent via the Internet to a computational farm for analysis. “It’s reasonable to assume that in future such services will be available,” Eskow said. “They will look at the data that horticulturalists send them, do some analysis, then send back a dashboard that says, Here are your plant’s metrics and here are some things that need to be changed.”

  On its first public outing, at the 2016 edition of Lightfair in San Diego, Eskow’s scale-model greenhouse of the future caused a sensation. “The response was unbelievable,” Eskow told me. Curious lighting company execs crowded round. Eskow was obliged to repeat his explanation of what was happening inside the box so often that, within a few hours, he had lost his voice. Among those drawn to see the demo was Shuji Nakamura, the Nobel prizewinner whose invention of the brightblue LED just twenty-three years previously had set off the solid-state lighting revolution. Also in attendance were many of Avnet’s large lighting customers. “For them horticultural lighting is a green field, no pun intended, a way to leverage their existing capabiliti
es,” Eskow said. “With consumers becoming more aware of healthy and organic means to grow plants, it’s a huge opportunity for lighting companies.”

  One company that recognized the opportunity was Acuity Brands. In February 2017 the company announced that it was sponsoring a research program at Bob Karlicek’s Center for Lighting Enabled Systems at the Rensselaer Polytechnic Institute. “We are excited to be working with Acuity Brands to to develop LED solutions that will enhance and accelerate crop automation, while delivering greater energy savings,” Karlicek said.

  There were those who claimed that LEDs were the greatest innovation in plant growing since the invention of the tractor. A bit over the top, perhaps, but there seemed little doubt that LEDs represented the future of horticultural lighting. The question was not if they would dominate, but when. As of 2016, however, according to researcher Strategies Unlimited, LEDs had managed to snare just one percent of the $5.5 billion horticultural market. But, as more and more growers latched onto the benefits of solid-state lighting, the changeover was beginning to pick up speed. The firm expected that by 2021 the penetration of LEDs would increase to 14 percent.

  C H A P T E R E I G H T E E N

  Play of Brilliants T he future of lighting, as of most things, has its roots in the past. At the Massachusetts Institute of Technology in the late nineteen forties the electrical engineer Parry Moon and his colleague Domina Spencer worked out that a luminous ceiling would provide ideal visual conditions - “an even glow of illumination, without glare or shadow” - for office workers. Sheets of translucent plastic would diffuse the light, making it seem to come from an unbroken flat plane rather than from rows of fluorescent

  tubes. The pioneering lighting designer Richard Kelly implemented luminous ceilings as a signature feature of the Seagram Building, completed in 1958 in midtown Manhattan. The custom-made installations were outfitted with two independent circuits. One was for daytime illumination; the other, for after dark, used separate lamps to turn the skyscraper into a glowing tower of light. Because hugely expensive such fancy lighting systems were necessarily reserved for only the most iconic of architectural spaces. The idea that luminous ceilings embodied, of using light as a structural material like brick or steel embedded into the very fabric of the building, would have to wait more than half a century for a technology that enabled it to come to fruition.

  Among his many contributions to the nascent field, Kelly defined three key concepts to describe the effects that lighting design could achieve. “Focal glow” was like a shaft of sunlight bursting through the clouds; “ambient luminescence,” like a snowy morning in open country; “play of brilliants,” like a ballroom lit by crystal chandeliers sparkling from a thousand candle flames. Brad Koerner, director of the Luminous Patterns group at Philips, liked to use Kelly’s concepts in his presentations, “because they really help non-lighting people get their heads around the potential of lighting in architecture.” For Koerner the need for embedded lighting was obvious. “It’s not some clever new weird thing,” he said. “There’s this pent-up demand in the design community for treating light as a material. It’s just the old technologies were not able to keep up.”

  Like Kelly (and many other lighting designers), Koerner was trained in theater lighting, an art form in which spotlights, floods, and other types of illumination are used to provide dramatic effects. Growing up he had wanted to be a Walt Disney imagineer. As an architecture student at the University of Virginia, Koerner took theatrical lighting classes in the drama department. He found them much more stimulating than the dry, engineering-driven approach taken by architecture school, which essentially boiled down to calculating how many fixtures were needed to light a given space. For him, the experiential took precedence over the functional. “I understand both sides of the world,” he told me, “but I think the future of lighting lies in the experience, creating distinctive new things for people to cherish.” As part of his master’s degree course at Harvard’s Graduate School of Design in 1999 Koerner did an elective under Sheila Kennedy entitled “Bugs, Fish, Floors and Ceilings” that took its cue from the bioluminescence found in nature, produced by many creatures including fireflies and squid. Kennedy anticipated that lighting would become a material that would be integrated into buildings. Her students experimented with incorporating electroluminescent displays into plywood and mixing phosphorescent powders into concrete.

  For his thesis Koerner decided to demonstrate luminous surfaces with interactive controls applied to a retail store. At the University of Virginia his professor had alerted him to the existence of an outfit called Color Kinetics that was doing exciting new things with LEDs. He went to visit the company at its headquarters in historic downtown Boston. It was a meeting of like minds. The folks at Color Kinetics in particular Kevin Dowling, its vice president of strategic technologies, immediately got what Koerner was trying to do. The firm agreed to sponsor his thesis, lending him $20,000 worth of its equipment for his demo. Dowling subsequently hired Koerner for an innovation team whose other members were Brian Chemel and Tom Mollnow, an industrial designer. Their mission was to determine how LEDs could move beyond being merely a like-for-like replacement, to create novel forms of light. “Kevin put the three of us together because he was concerned that Color Kinetics was losing its advanced status,” Koerner said. With hindsight, it was clear that the firm had had little to worry about. In 2005, when he joined, it was still way ahead of its rivals.

  Color Kinetics’ greatest advantage was that it was an outsider. “The company was started by a group of robotics guys from Carnegie Mellon who had zero lighting industry experience,” Koerner explained. “That’s why they were able to create such radically different products. They didn’t listen to the market, because they didn’t have any idea what the market was. They had no idea of the basics of how you make a downlight or a linear pendant or any of these ancient paradigms. They were just geeks messing around with the technology.” Color Kinetics was able to come up with new form factors for light fixtures almost by accident. One of these was a twelve-inch stick of color-changing cove lighting that could be used to make entire walls glow. “Not only did that product not exist before,” Koerner said, “it would have been inconceivable using any other lighting technology.” Another innovative product was called Flex. Deceptively simple, it resembled a string of colored Christmas tree lights. Flex allowed designers to combine modules to do everything from small projects to lighting up the San Francisco Bay Bridge. Color Kinetics did not offer its customers much support for incorporating its products into their construction projects. “We just said, OK, here you go — have fun with it!” That was fine for the adventurous and the tech-savvy. But most architects and lighting designers, Koerner realized, needed a helping hand. They wanted complete solutions, not individual bits of electronic kit.

  At Color Kinetics Koerner had worked on several commissions that involved embedded lighting. Each time it had been “like a science project,” he said, a one-off experiment, a frustrating, time-consuming process. “You have to figure out what gear to use, get samples, make mock-ups, design custom details.” Then there was the hassle of coordination. “Who puts all this together on the construction site, who makes sure it runs properly? Is it the electrical guy, the millwork guy, or some special system integrator who’s gonna charge you exorbitant rates?” A construction site was an expensive place to do R&D. Only clients with deep pockets - like owners of mega-casinos or five-star restaurants or oilsheiks wanting a signature building - could afford such vanity projects. That left a lot of lighting designers who would have loved to do embedded lighting but couldn’t because their projects didn’t have the budget. The advent of LEDs represented a wonderful opportunity to reduce the complexity and the hidden nuisance costs of getting such projects onto regular construction sites.

  In 2008, following its acquisition by Philips, Koerner quit Color Kinetics. Four years later, lured by the prospect of working with the charismatic lighting designer
Rogier van der Heide, he rejoined Philips. In October 2012 he finally got the chance to implement his vision of luminous materials. Philips has an innovation group that is tasked with incubating new businesses. Koerner made his pitch to its board. It advanced him some seed money to build a prototype. The board liked what it saw, giving Koerner the green light to set up Luminous Patterns as an internal venture. He and his team built a custom LED node to which they added special optics and controls. The nodes were built into panels that featured a variety of patterns. Lights could be dots, strips, diamonds, or honeycombs. They could be crafted into three-dimensional sculptured shapes, like flowers or a collage of butterflies. The lights could be connected visually by printing graphic designs on top of the panels. Each light was individually addressable, allowing them to glow on and off in dynamic animations. “One of the first effects we wanted to explore was the beauty of candlelight,” Koerner said. “We wanted to take the golden warmth, the soft brilliance, the sparkle that you get from glass around the candle and apply it to an architectural material.”

  Koerner knew that to impress potential buyers, it was no good showing them a meter-square panel that was stuck on a wall, like a painting. That would be like giving someone a brick then asking them to imagine a building. What he needed was scale. “I don’t want to be some little piece of light art on the wall,” he said, “I want to be the whole wall.” Koerner’s pride and joy was his showroom, which opened in Eindhoven in March 2016. It mounted fourteen large walls and ceilings, the largest measuring five meters long by two and a half meters high. There was, he thought, “a physical presence” to these panels. Each was capable of displaying animations and various different lighting effects. The walls were set in realistic situations like the lobby, bar, and bedroom of a hotel, or an athletic-shoe store. “People walk in and they are just blown away,” he enthused.