10 Years Later: Changes in LED Lighting for Plant Growth
Since emerging onto the indoor growing scene, LED lights have come a long way. Chris Bond explores how LEDs have changed over the past 10 years and what the future looks like for these energy saving grow lights.
Light emitting diode (LED) technology used in artificial lighting for plant growth was once the purview of researchers and experimentation by professionals. Its development held great promise for more efficient and cost-effective lighting solutions for indoor growing. It has only been in recent years, however, that these advances have trickled down into the realm of the home grower, hobbyist, or even smaller commercial grower.
All along, growers of all sizes who were in the know have wanted LED technology to become the go-to solution for grow lights. LEDs last longer than more traditional types of grow lights and they are far more efficient at converting energy to light. High pressure sodium (HPS), metal halide (MH), and ceramic metal halide (CMH) lights (which had all been the industry standards for grow lighting until LEDs came on the market) burn hotter than LEDs, which poses risks to crop quality and health. These more traditional grow light options are generally less durable than LEDs and by and large cannot be customized in the ways LEDs are being produced to be.
LEDs were a game changer for these features. Until the last few years, though, they were largely cost-prohibitive for the average grower and even commercial ones or, at the very least, they were just not an economical lighting source for growing plants.
Fast-forward to today and LEDs are holding their own and gaining many converts. They continue to get more and more efficient, customizable, and even more cost effective. Most experts believe LEDs will take over and eventually dominate the world of indoor horticulture. The reasons are many and varied but they can be reduced primarily to two main factors: better technology and lower costs.
LED Technology and Advances
LEDs are a great fit for plant growing operations because their features are suitable for most growing applications. They are small, durable, long lasting, and cool burning. LEDs are also highly efficient in converting energy to light. They were not, however, initially developed as grow lights for plants.
LED technology traces its origins back to the late 1920s. It did not really become a viable technology for general use until research in the 1960s, but no one was looking at them for their horticultural potential. Their application to the world of grow lighting was first looked at by none other than NASA in the 1990s as they were developing best practices and viable options for plant-growing systems as they contemplated future bases on the moon and distant planets, as well as for astronauts being able to grow their own food on long-term voyages. At that time, however, only red LEDs were available. Until the addition of blue LEDs on the market, they were not ready to be viable for grow lighting.
LED technology advancement continues to allow for the use of several different colors beyond just blue and red to assist in plant growth and development. Unlike with most traditional grow lights, growers can select colors now that correspond with various stages of plant growth and respond to different species of plants’ need for various parts of the visible light spectrum. LED lighting can be selected (or in some cases programmed) to provide light from the white or blue side of the spectrum for earlier development stages and the transition to the red side of the spectrum for maturing plants.
(Read also: Red Light, Blue Light: Balancing LED Efficiency with Performance)
Other advances in technology in recent years have to do with variable spectral output. This variability can be in response to such conditions as where the LEDS are located within the plant’s canopy or even where a light is in relation to other grow lights in a growroom or greenhouse and their respective outputs. Arguably more impressive is the emerging ability for LED fixtures to respond to such location-bound situations as latitude. For example, LED light technology has advanced so it is possible to fine-tune a fixture’s output in response to the reachable solar radiation based on its position on the globe. They can also be designed based on a region’s power grid to emit the appropriate amount of light based on power consumption.
While all of these advancements are impressive, LEDS continue to make strides in more simple ways too. LED fixtures are becoming more waterproof, which of course makes them safer to use around irrigation systems than traditional grow light options or even older LED models. Their housing is constantly being upgraded and improved upon to be able to withstand the variable climatic conditions that are found in greenhouses and growrooms. One of the greatest improvements in LEDS over the last decade appeals to almost all growers universally: the drastic reduction in cost.
LED Lighting Costs
As LEDs increasingly continue their path to become the most popular grow light option on the market, their costs, fortunately, continue to decrease. Besides the concept of economy of scale, one of the single biggest reasons for this is the cost of producing the semiconductor chips used in the manufacturing of LED lights has decreased by approximately one-millionth of their original cost since the mid-1950s. They are now made for just a few cents per piece.
Bans by major global economies on incandescent lighting by the U.S., E.U., and China has in no small part also helped the development of cheaper LED technology. For example, from 2008 to 2016 the cost of a single LED light bulb for home lighting dropped 90 percent because of the proliferation of LED technology and the encouragement of its further development all over the world. This reduction in price is likely to continue as more countries encourage the development and use of LED technology for their environmental benefits. LEDs as compared to more traditional lighting sources (grow lights and otherwise) reduce overall energy consumption which means less greenhouse gas emitted in the production of electricity to run them. This also leads to lower CO2 emissions and, less importantly, but a real issue in some places, LEDs help to reduce light pollution.
LEDs were once something that only folks with a high amount of disposable income or institutions that could obtain grant funding could afford. Costs of LED fixtures and accessories have reduced significantly to the point where they can now fit into almost any budget of any size. This corresponds with the principle of Haitz’s law. According to Haitz’s law, every decade sees a tenfold decrease in the cost per unit of useful light emitted per each waveband, while the amount of light emanated from each LED increases twentyfold. Continued reductions in costs are likely, but there are also other future benefits to look forward to.
Future of LEDs
The future of horticultural lighting going forward is owned by LEDs. No longer a novelty or research tool, they are finding their way into the mainstream. Even with how far they have come over the last 10 years, there is still much farther for them to go. There are still applications or situations where they might not make the most sense for all growers.
For growers that do not grow year-round, or have fallow periods in their growrooms, LEDs may not be the best bet. The value in LEDs is realized when they are used often. The more hours LEDs operate, the quicker the ROI in electricity savings and maintenance costs.
In growrooms and greenhouses where the lighting must be hung high, more traditional types of lighting may be more appropriate as well. LEDs are, however, proving to be the most efficient and effective choice in vertical farming applications where they are taking a center role.
As the trend of vertical and indoor farming continues to gain popularity, so does the use of LED lighting in those environments.
(Read also: The Best Hydroponic Systems for Space Optimization)
Vertical farming is gaining traction and attention as it allows for the high-density production of food and plants in and on multiple layers. As this technique continues to evolve, so does the technology of and applications of LED lighting to accommodate this newer growing practice. Advances in smart technologies, sensors, and cloud-based operations are being utilized with LED grow lights in ways not previously thought possible.
With the help of embedded software and cameras, some LED systems can detect early onset symptoms of pest and disease issues. Utilizing algorithms, these lighting systems can communicate remotely in any number of ways. Other LED systems are smart enough that they can fluctuate their output based on real-time lighting conditions, considering the different growth stages of plants, and their need for various spectra of light at each respective stage of development.
It is highly likely LED technology will continue on its current trajectory of becoming more precise, more programmable, more targeted in its output, and more cost effective. If the past 10 years of advancements are any sign of the next 10, then we will continue to be amazed at just what LED lighting means not only for the grow lighting industry, but the horticultural industry as a whole.
Written by Chris Bond | Certified Permaculture Designer, Nursery Technician, Nursery Professional
Chris Bond’s research interests are with sustainable agriculture, biological pest control, and alternative growing methods. He is a certified permaculture designer and certified nursery technician in Ohio and a certified nursery professional in New York, where he got his start in growing.