Urban Farms Shine On: New LED Capabilities Bring Agriculture to the City

Agrilyst Inc., a Brooklyn, N.Y.-based software company servicing this market, sees indoor farming as “one of the fastest growing industries in the United States.” LEDs will be instrumental.

Old McDonald may have a farm, but these days you don’t have to leave the city to find it. Urban agriculture is bringing farm-to-table in the purest sense to metropolitan customers while rewriting crop yields and farming resiliency. Agrilyst Inc., a Brooklyn, N.Y.-based software company servicing this market, sees indoor farming as “one of the fastest growing industries in the United States.” LEDs will be instrumental.

In its August “State of Indoor Farming” report, Agrilyst states, “By enclosing farms, indoor growers can use technology to control farm inputs and to create artificial environments within their facilities.”


The urban farming industry sees its future as data- and ­technology-driven. LED lighting, building control systems, sensors and other services put electrical contractors front and center.


“You can’t farm indoors without lighting,” said Patrick E. Hughes, senior director—government relations and strategic initiatives, National Electrical Manufacturers Association (NEMA). “LED makes it more cost-effective. [LEDs] are also highly tunable, so you can adjust the wavelength of light to stimulate the plant growth and increase crop density.”


NEMA may take on urban agriculture as a strategic initiative promoting safety, efficiency and optimized operation. Indoor farming requires less water and fertilizer use, too.


“It’s a very data-driven, scientific farming enterprise,” Hughes said. “You are automating water feed and nutrients onto the plant roots, applying minimum amounts of each. Sensors give feedback on temperature, evaporation, mist application, humidity levels and CO2.”


Serving the urban farmer opens the door to multiple opportunities for ECs, including lighting, control, submetering, energy storage and more.


“Indoor farms are a substantial user of electricity, so efficiency is important,” Hughes said. “They will also need backup generation. A possible need for heavier electrical work is there for contractors able to upgrade transformers and the electricity distribution feed to these facilities.”


In the Agrilyst report, 86 percent of survey responders said they planned to expand their facilities (at least 4.7 times larger) in the next five years. Market expansion in five years could grow anywhere from $3.7 billion to $6.8 billion.


Common crops grown indoors include greens (lettuce, spinach), herbs, vine crops (tomatoes), cannabis, some fruits (strawberries), and flowers or nursery crops. More than 91 percent of indoor farmers grow year-round with the majority selling directly to consumers and restaurants.


In vertical farming configurations, crop beds are racked and stacked.
In vertical farming configurations, crop beds are racked and stacked.

 

A vertical farm in action


Green Sense Farms in Portage, Ind., grows products free of pesticides, herbicides and genetically modified organisms (GMOs), all advantages of vertical farming. It uses horticultural LED lighting for its crops, which include micro greens, baby greens, herbs and lettuce (its biggest seller). Typical harvest for outdoor-grown lettuce ranges from four to five cycles a year.


“We have enjoyed between 18 to 26 lettuce harvest cycles depending on customer-requested lettuce-head size,” said Robert Colangelo, founding farmer and CEO of Green Sense Farms. “To grow butterhead lettuce in a field farm would require 10 acres. Grow that same product in a greenhouse [and it is] approximately three acres. A vertical farm, a half-acre footprint. There’s the shipping difference. Why get produce in Indiana from the West Coast when you can get your produce locally? There are fewer handling and distribution touch points, so product reaches the consumer fresh, a much better product. You avoid that process of harvest to packing house to distribution center, the customer distribution center and finally the store.”


Most of Colangelo’s customers pick up their ordered produce at the Portage farm. Grocery stores are the biggest customer segment. The company also supplies its produce to institutional kitchens (e.g., country clubs, corporate cafeterias and schools) through produce companies.


Colangelo feels LED horticulture lighting is what makes indoor vertical farming possible. Growers previously used white fluorescents, for the most part. Fixture heat meant placing light farther away from the plants, reducing yields. Short fluorescent life cycles meant added labor and material cost. The generated heat also meant the HVAC system worked harder. LED technology has remedied these issues, including the ability to grow more levels of racked and stacked beds of plants (towers), the vertical farming configuration.


“Our HVAC equipment is smaller and runs less often,” Colangelo said. “We’ve cut down on maintenance and labor because the LED light lasts five to seven years instead of months with fluorescent.”


There are more complex benefits, as well.


“With LED, the wavelength of the light helps promote growth,” Colangelo said. “Differences in color spectrum can decrease growing time and increase plant attributes like color, taste and leaf size, something our customers demand. PAR [photo action radiation], which we measure for plant growth, is increasing and getting cheaper as LED lights get more efficient. We are all just beginning to discover how to use LED light.”


Green Sense Farms is located within a converted warehouse that required improvements in drainage and electrical capacity. Colangelo described the grow space as “rooms within rooms.”


“Our grow rooms use sensor and automated control devices to manage the climate, turn on lights, inject CO2, and control irrigation and drainage,” Colangelo said. “We developed a proprietary system that optimizes our growing while using a minimum amount of energy. In vertical farming, you need to control nutrient and irrigation cycles, climate and lighting. Unlike a greenhouse, there is no connection to the outside. Our strategy is to build a network of farms in the U.S. and Canada that are net-zero energy, zero waste and water efficient [with] closed-loop irrigation and water treatment. We also want to license our technology abroad.”


Horticultural LED lighting helps increase growth of crops such as micro and baby greens, herbs and lettuce.
Horticultural LED lighting helps increase growth of crops such as micro and baby greens, herbs and lettuce.

 

Lighting manufactures pay attention


Major manufacturers, such as Cree, GE and Hubbell Lighting, offer horticultural LED products. Philips Lighting—20 years active in the agricultural lighting field—also supplies both high pressure sodium (HPS) and LED technology called GreenPower. One “production module” LED fixture is specifically tailored for vertical farming. Offering an even light distribution, the vertical arrays can be tuned to foster growth of vegetables, soft fruits, leafy greens and perennials.


Michael O’Boyle, senior technical policy manager—standards and regulations for Philips Lighting, sees agricultural LED lighting as a niche with a lot of promise.


“The idea of vertical farming [production facilities] and local produce has been building over the last few years,” he said. “It may be the wave of the future. You are farming without the need for pesticides, you use less water and far less land. You are also supplying food locally. It really is a new frontier.”


O’Boyle said LED lighting placement in vertical farming is more varied than commercial or other applications.


“You want light on the leaves of the plants, but if the lighting is just top down, you are only prompting top growth,” he said. “Light must hit every part of the plant, so down and up lighting and focused lighting between plants. You do move this light around, mount it in different ways. It’s reliant on flexible cords and different connection systems.”


Research and development (R&D) plays a big role.


“Our corporate R&D is conducted in the Netherlands [global corporate headquarters],” O’Boyle said. “Technicians are working on what are called ‘formulas’ that explore different interactions between plants and LED lighting. The needs of a tomato plant differ from a head of lettuce, requiring a different LED spectral output. A formula would inform an indoor farmer that, if you are growing ‘that,’ this is how you tune your LED arrays.”


Making discoveries


Universities around the globe are exploring LED interaction with plants. Green Sense Farms, for example, is working with Purdue University, University of Arizona, University of Notre Dame, Ohio State University and University of Guelph in Ontario. In a lab at the University of Florida, researchers have been controlling the flavor of fruits and vegetables, nutrient content and/or product quality using LED narrow-bandwidth light. Students and faculty have reprogrammed plant materials.


Kevin M. Folta is a professor and chairman of the University of Florida’s Horticultural Science Department. With a lab in his name, Folta has spent 10 years examining the interaction of LED light and plants.


“Any wavelength of light will promote photosynthesis,” Folta said. “Our investigation is in how to use a narrow band of light to promote, develop and create specific metabolic changes. We can turn on 300 genomes with LED lights that are normally turned off. We manipulate what’s there, avoiding nonchemical treatments.”


Flavor has been particularly challenging, but progress is being made. Using LED wavelengths, scientists have modified volatile compounds such as sugars, acids and aromatics.


“Discovering what is affected through the light spectrum gives us precise buttons to push to reprogram, say, fruit,” he said. “For instance, the sweetness of strawberries is influenced by blue lighting.”


The University of Florida and others have found that anti-cancer compounds (glucosinolates) in certain greens and green vegetables can be modulated. Vitamins A and C also are controllable by LED wavelengths. Blue and far red lighting (unseen by the human eye) helps manipulate these properties. Plant quality—including leaf shape, size and pigmentation—also can be influenced.


“I am very excited about our work exploring LED pulse light treatments to promote plant growth while reducing energy costs,” Folta said. “Light might be applied for five seconds and then turned off for 10 seconds over a 24-hour period. LEDs are very efficient, but this pulse approach would cut an energy bill by 35 percent. Vertical farming would be a great fit.”


Colangelo believes vertical farming is just getting started.


“There is a lot of promise evident by the R&D activity in universities, investors such as Jeff Bezos [founder and CEO of Amazon] and the success of vertical farms succeeding,” he said. “It’s a time of growth and evolution.”


About the Author

Jeff Gavin

Freelance Writer
Jeff Gavin, LEED Green Associate, is the owner of Gavo Communications, a sustainability-focused marketing services firm serving the energy and construction industries. He can be reached at gavo7@comcast.net .

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