Almost all of the most recent research into greenhouse lighting has focused on light-emitting diode (LED) technology. There’s a good reason for this, as the long-term energy savings that can come from the use of LEDs — and the rebates and local grant programs that growers can take advantage of — make it an appealing option.
So why are only around 2% of greenhouse ornamental growers (according to Erico Mattos, Executive Director of the GLASE consortium) using LED systems? If you talk to industry suppliers, there is a host of reasons.
“Lighting, on average, is 50% of a commercial operation’s energy costs, but the economic feasibility of switching to LEDs is not always the most important thing on growers’ minds,” says Taylor Schaberg, Managing Director of ActiveGrow. “Most growers are hesitant to change to LEDs due to their prohibitively high cost, even if they can get that money back within one to two years from energy savings and potential rebate opportunities.”
In some cases, Schaberg says, growers have dialed in their operations to work successfully with HPS lighting systems, so using all new LEDs is off-putting.
“As technology changes and LED prices drop, some growers feel they can wait until these systems become more affordable up front to jump in,” Schaberg says.
Other Factors for LED Reluctance
• Lack of information. “For the most part, growers are hesitant because they are not familiar or have a lack of experience with LED lighting,” says Christina Ackley, Director of Marketing at Illumitex. “Early on, LEDs had a perceived bad rap, with little or no substantiation.”
• Low priority. There’s been a huge shift in the acceptance of LEDs just in a matter of two or three years, according to lighting experts at Signify. However, as everyone knows, managing labor costs and availability is the biggest challenge facing growers today, which means investments in equipment like transplanting systems or picking machines are often given higher priority over investments in lighting upgrades.
• The challenge of change. For growers who truly understand the value of light and recognize the need for light, sometimes it’s the simple challenge that comes with change. Wading through all the information that is available about LEDs can be overwhelming and daunting, according to Signify.
• Proof of concept. “Based on our experience, the main reasons a fairly large contingent of growers is reluctant to make the switch to LEDs are the still relatively high cost of LEDs versus traditional light sources, and also that the growers feel LEDs are still fairly unproven within the horticultural space,” says Lisa Jansen van Rensburg, Marketing Manager at PL Light Systems. “They are reluctant to risk a potentially negative impact to their yield in the interest of experimenting with LED lighting.”
• Production changes. When transitioning from HPS to LED, some growers have noticed significant differences in the nutrient and water intake of their plants, Jansen van Rensburg says.
“There will be a transition period as the grower learns to adjust the feeding/watering regimens accordingly,” she says. “The timing of the growth cycle will most likely also be affected.”
• Varietal differences. LED spectral recipes are often confined to wavelengths within the PAR region of the spectrum, which can work really well for a specific varietal of a given plant species, but deliver poor results when used to cultivate another varietal of the same species, Jansen van Rensburg says.
“HPS lamps, on the other hand, deliver a wide range of wavelengths, providing a far more forgiving lighting environment across multiple crops and varietals,” she says
Why the Tide Might Be Turning
Even with these challenges, the industry is continuing to advance intelligent lighting controls to automate schedules and production as greenhouse technologies and building system integrations become more connected.
“Growers are starting to recognize adjustable spectrum LEDs as a viable and proven solution to traditional HPS lighting as a means to accelerate harvest cycles and balance energy efficiency with efficacy and crop performance,” says Ali Ahmadian, CEO of Heliospectra.
PL Light Systems’ Jansen van Rensburg also notes that those growers who are interested in LEDs will install them in a small trial area of their facility, even if they stick with more trusted or proven HPS lights for the majority of the greenhouse.
“LEDs are allowing growers to maximize their production and yield in facilities where other systems simply don’t make sense; for example, in areas where power and vertical space are limited,” Jansen van Rensburg says. “Add to this the many energy conservation programs offering good rebates on LED lighting, and growers have a very strong case for investing in LEDs. At the very least, we are also seeing a fairly strong trend toward hybrid (LED + HPS) installations, which affords the grower the best of both worlds.”
In terms of cost, LED fixtures today are much less expensive and more powerful than even two years ago. And the benefits are being recognized.
“LEDs work better than HPS operationally on several points: Less heat, longer life, less energy, and better environmental impact,” Ackley says. “LEDs also lead to more predictive and precise crop cycles (frequently shorter) and better quality results due to better spectrum delivery and light distribution.”
At Signify, the current focus is on grower-based solutions for those making the transition. Within the ornamentals market segment, Signify is working with several leading growers on custom light solutions, including American Takii, Iwasaki Brothers, Skagit Horticulture, Peoria Gardens, Van Belle Nursery, and DeGoede Brothers.
Travis Higginbotham, Director of Cultivation Support at Fluence Bioengineering, perhaps sums it up best when he says the industry is just starting to understand the benefits of LED technology and what environmental variables are introduced when switching to LEDs.
“There is not so much a hesitancy from growers, as there is a desire to understand how they will need to adjust HVAC, humidity levels, and other environmental factors,” Higginbotham says. “Our team is continuing to hone the energy efficiency of our LED solutions, and looking to educate and work closely with growers to ensure they adjust their environment to account for this benefit.”