Morgan Pattison, founder and president of Solid State Lighting Services Inc., says advancements in LED technology will have a major impact on the production of horticulture crops.
By David Kuack
With a PhD in materials science from the University of California-Santa Barbara, Morgan Pattison has long believed that light emitting diodes (LEDs) were going to eventually dominate the illumination market. His thesis research advisor was Dr. Shuji Nakamura who invented the blue LED. Nakamura received the Nobel Prize in Physics in 2014 for his invention.
“Professor Nakamura was instrumental in showing me the importance of this technology and this put me in a good position to be involved with LED research,” said Pattison.
Pattison started Solid State Lighting Services Inc. in 2008. The company, which focuses on LED lighting, provides technical consulting to other companies and organizations assisting in understanding how the technology of LEDs fits together.
Scouting for DOE
“Our biggest and longest running client is the Department of Energy,” Pattison said. “I operate as a contracted senior technical advisor to the DOE SSL Program. In that capacity, I do a lot of technology and scouting and looking for what is coming down the road in terms of applications for lighting. The LED technology platform continues to change what’s possible with lighting and this opens up new applications for lighting.
“The initial mindset is you change one bulb out for another bulb. It’s just changing the technology. But when the platform has so much more fundamental functionality then it’s not just a case of changing one bulb for another. Then you can change to a bulb that has extra features. That opens up new applications or expands use of existing applications for the technology. The technology keeps getting better and that keeps expanding the possibilities on the application side.”
Pattison works with the DOE to understand new components and materials that will advance the status of the technology and to determine promising R&D investment.
“DOE makes the decisions. I act as a resource for them,” Pattison said. “I try to understand how new applications will influence the technology development and also change the current energy landscape for lighting. Lighting uses about 20 percent of all electricity in the U.S. It is a big consumer of energy. New technology is going to change that. However, there also may be new applications which may use more electricity, but this can be okay if they are a more productive use of electricity and cut energy in different places. Lighting for horticulture is a prime example of this.”
In January 2018, DOE released a horticultural lighting energy report, Energy Savings Potential of SSL in Horticultural Applications. Pattison, who was one of the coauthors of the report, said the publication addresses the energy implications for horticultural lighting and transitioning it from conventional sources to LEDs.
“I engage with horticultural experts in talks and meetings to try to connect them with my understanding of LED technologies so that they can make informed research decisions,” he said. “There is a lot of information floating around about horticultural lighting. Because there are not a lot of defined characterization standards, it is more difficult to debunk some of the claims being made.
“From a market perspective or a consumer perspective, having more comparable performance of products is important, and that requires test standards. Everybody needs to be speaking the same language in terms of test characterization standards for products. This is something that happened very similarly with general illumination. Before there were standards that were applicable to LED lighting, there were all sorts of wild claims from lighting producers that really kind of flooded the market and slowed down the adoption of the technology. That is a market need that exists for horticulture. The standards for LEDs are what A.J. Both at Rutgers University has been working on. He got the idea from the existing lighting label for general illumination. LED lighting for general illumination went through the same growing pains that are now occurring with LED horticultural lighting.”
Lighting advancements to impact horticulture
Pattison said as advancements are made in LED technology there could be an individualized LED light for each type of application.
“In the past there were only a handful of different bulbs,” he said. “There weren’t a lot of lighting technologies or options to choose from. In horticulture, generally speaking, growers are using high intensity discharge street lights to illuminate their crops. Most growers are still using street lights because right now that’s what works best for them.
“We are going to see more refinement on the application side because we have so much better control of the light in general. There is so much more that can be done with current LED technology. There is work that can be done at the LED level making them better still, including all of the materials and packaging.”
Pattison said improvements can also be made with the lighting fixtures and light distribution systems.
“In the case of greenhouses or vertical farms, this could affect how a room is organized, how plant trays are situated.,” he said “With horticulture, there is a lot of room to improve it to make it more economical and more effective all the way around.”
Pattison said another impact LED technology could have on horticulture is how greenhouses or any other growth environment are designed.
“The previous growth methodologies relied on previous lighting technologies and their restraints and shortcomings,” he said. “When those don’t apply any more, then the whole building design may need to be reconfigured. In greenhouses, for example, if a grower is providing LED light that may cause a change in the orientation or setup of the building. It may be a case of taking advantage of the sunlight during the day and LEDs at night. That is something that really has to be thought out for all types of controlled environment agriculture.”
Pattison said LEDs could also revolutionize how plants are bred and grown.
“Vertical farms are really revolutionary structures,” he said. “I heard one horticulturist say, “When plants are grown in a controlled environment they could be tweaked to take out a lot of their natural defense mechanisms because there’s not going to be pests, there’s not going to be floods, there’s not going to be droughts. All of the elements of the plant take energy to deal with these outside issues.” Plants could really be simplified if the focus was placed primarily on reproduction or production of whatever a breeder is looking for. A tomato could be bred for the easiest light recipe to give it. There is a development cycle that hasn’t been completed yet.”
Pattison said the transition to LED lighting has also forced everyone to rethink the change-out cycle for lighting products.
“We’re moving away from having light bulbs at all because LEDs can last so long,” he said. “The lifetime of lighting products, including horticultural products, is characterized based on how long it takes the output to depreciate by a certain amount. There are other reliability considerations. With general illumination, a light bulb may be good until it reaches 70 percent of its initial output because humans are very forgiving with light levels. But in horticulture if the light drops 70 percent, then plant growth drops 70 percent.
“There are different LEDs for horticulture. Red LEDs have different lifetime constraints than blue or white LEDs. Horticulture applications use more red LEDs and the LEDs can depreciate at different rates. The color could change to a less optimum level.
“There is also a catastrophic failure rate. LEDs might last 50,000 hours, but the light fixture itself could be an issue. There could be a bad solder joint, a manufacturing failure or a bad driver. There is a liability with horticulture that is different from general illumination.”
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail,com.