Growing with LEDs

Publication: 

PARsource

Author: 

Ron James

LEDs have become a popular topic of discussion amongst growers over the past couple of years. As technology has evolved and costs continue to drop, this form of horticultural lighting keeps gaining in popularity with both professional and hobby growers.

LED technology offers some exciting opportunities for growers when used in the correct application. Understanding the benefits of LEDs versus other types of lighting is fundamental when deciding which technology is the best fit for your specific needs.

BENEFITS OF LEDs VERSUS OTHER LIGHTING TECHNOLOGIES

Ability to design a specific spectrum - LED technology now allows us to be able to develop light systems with specific color spectrums. LEDs have also made it possible for researchers to experiment with how different plants respond to specific wavelengths and spectrum combinations.

Longer lamp life for reduced maintenance costs - LEDs have a longer lifetime compared to traditional HID lamps and need replacing less frequently, leading to savings in equipment and labor.

Lower heat output is beneficial - LEDs emit less heat energy than other grow lights, reducing the need for costly climate control in indoor growing environments.

LEDs allow for different form factors for greater versatility - With the capacity to be developed into different form factors, LEDs are suitable for a variety of growing applications.

We’ve found that the best utilization of LEDs is on vertical grow racks, in light spectrum research and with indoor growing. The lower output and cooler running temperatures of LEDs makes them ideal for grow racks that position the plants in close proximity to the light.

The ability to modify and experiment with the light spectrum makes LEDs a valuable research tool in the area of horticultural use and beyond. Indoor growers are finding “full spectrum” LED lighting to be especially useful when artificial light is the primary light source.

Energy saving potential - Depending on the application, an LED fixture may be a 1:1 swap with traditional HID grow lights in terms of light output. When that is indeed the case, it’s likely that energy consumption will drop, and with it, operating costs.

CONSIDERATIONS WHEN PURCHASING LED LIGHTS

There’s a lot of information floating around the internet stating that LED lighting has improved to the point where a lower wattage LED can replace a higher wattage HID fixture with the same or higher light output. We have found this statement to be true in most cases IF you are only comparing one LED to one HID fixture.

LEDs by design are extremely focused, and light readings taken below an LED fixture as compared to an HID fixture may show that the LED has a more intense output.

This can be misleading, as commercial growers don’t grow under one light. A high output light that is intense below the fixture and that also provides an intense spread of light is desirable for large grow areas. A good lighting design and setup will overlap the light spread, for consistent and uniform light coverage throughout the growing area. This is best achieved using HID lighting.  Accomplishing the same uniformity using LED lighting would require more fixtures to compensate for the lack of light spread.

Consult with a professional before making a purchase - It’s critical to enlist a professional lighting company to design a custom lighting layout before purchasing horticultural lighting. When reviewing the layout, make sure that the calculations are based on the specific growing region—growers in Canada will need more supplemental lighting than those in a sunnier region further south. Consider the uniformity as well as the average intensity to ensure a correct design.

Costs and ensuring the best return on investment (ROI) - This is when doing your homework pays off. It’s important that you understand the cost and return on your investment involved with your lighting project. Scrutinize the details of the ROI figures, armed with the knowledge that incorrect costs are often provided. LED fixtures will be considerably more expensive to purchase, but may come with lower operating costs, and don’t forget that replacement intervals are longer than with traditional HID lights. 

Another factor is the length of time the lights will be running. Sometimes ROI calculations will be based on a 12 month schedule, when in reality, supplemental lighting in a typical greenhouse situation will be run for only 4 months out of the year.

LEDs offer some exciting advantages and opportunities for specific growing applications, but it’s important to understand the differences between the lighting technologies. This will help you identify which technology makes the most sense for you.

 

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