They adorn our Christmas trees and illuminate our auto headlamps. Now, LED (light-emitting diode) lights are making their way to the dairy barn.
David and Amy Petersen, owners of Majestic Manor Dairy, a 120-cow registered Holstein enterprise near Davenport, Iowa, became interested in LED lighting for their farm in 2009. "We were in the process of remodeling our kitchen and found for the first time high-quality, bright, white LEDs for the under-cabinet lighting," explains David Petersen. Always a conservation-minded producer, Petersen began researching the availability of LED lamps to replace the less-efficient fluorescent lamps in his parlor and freestall barn. It was a process that took almost four years.
"I could find 4-foot LED lamps, but we needed 8-footers, and I did not want to incur the additional labor and expense of replacing the fixtures along with the bulbs," he says. The breakthrough in his search came last summer, when he was touring a cottage cheese plant in Carbondale, Ill., and noticed the facility used 8-foot LED lamps.
An inquiry led him to Zeus LED, Inc., a Carbondale-based start-up owned by David Wilson. An electrical engineer by training, Wilson became interested in LED technology in college and started the company in 2009. He holds several patents and works directly with a manufacturing facility in China to produce LED lamps according to his specifications while following Underwriters Laboratory (UL) standards.
The switch to LED
After thoroughly quizzing Wilson, Petersen was convinced that he had found a reputable supplier and purchased 70 LED lamps to equip a total of 35 fluorescent fixtures in his free-stall barn and parlor. In the parlor, they replaced T-2 linear fluorescent bulbs, while in the free-stall barn, they replaced T-12 high-output (cold-start) fluorescents. The parlor light fixtures called for pin-style connectors. The freestall barn needed wedge-style connectors. Wilson was able to supply both.
Petersen"s local electrician replaced the bulbs, a process that was a simple as changing the light bulbs and unhooking the fluorescent ballast in each fixture. The task took about 15 minutes per fixture, and Petersen couldn"t be happier with the results.
"The light is very clear and bright, and it has more of a ‘spotlight" effect versus the ‘floodlight" effect of the fluorescents," he says. Wilson explains that fluorescent bulbs emit light from 360 degrees, and it is directed down from the fixtures. LED lights, on the other hand, emit 120 degrees of light and send it straight out, which results in more direct lighting while drawing less power. Beams of LED-generated light also can be angled to specifically illuminate select areas, such as walkways and feed alleys.
Wilson says the Petersens" T-12 fluorescent bulbs generated about 70 to 80 lumens per watt of electricity, versus 104 to 110 lumens per watt for their new LED lamps. Additional energy is saved by no longer driving the fluorescent ballasts. The result: more light for less electricity.
Switching to LED lamps also resulted in no change to the Petersens" photoperiod lighting system in their free-stall barn, which ensures 16 hours of 20 footcandles of light per day from 6:30 a.m. to 10:30 p.m. The system is regulated by a master-timer switch and a photo eye to detect daylight, and continued to function consistently after the LED lamps were installed.
Best of all, Petersen estimates that the dairy"s monthly lighting bill has been cut by more than 60 percent since the LED lamps were installed last February.
LED lighting is not exactly "new" technology, as it first was invented in the 1970s. But Kevin Janni, professor and extension engineer at the University of Minnesota, says the technology and its applications have improved tremendously in recent years. "The light spectrum and quality is much more appealing now, and products that can tolerate moisture and dust are making LED lighting a more practical option for agricultural settings," he says.
Janni believes high-quality LED lamps are an excellent option for new dairy construction or remodeling because they are more efficient and last longer than fluorescent, metal halide or high-pressure sodium lighting options.
Wilson says the life of a well-maintained LED lamp is 50,000 hours or more, compared to 15,000 to 20,000 hours for the other common barn-lighting options. And, as a plus for outdoor and semi-outdoor settings, "they love cold," says Wilson. "They actually function better and last longer in cold conditions. I have tested them at conditions as low as -20'F, and they performed perfectly." He adds that LED lamps will function in extreme heat as well, but prolonged exposure to high heat (110 to 120'F) will shorten their lifespan. In addition, Wilson cites the following additional benefits of LED lighting:
• LED lights contain no gas or mercury, so government-regulated disposal is not required.
• Unlike metal halide and compact fluorescent lights, LED lights do not need to "warm up." They produce instantaneous light as soon as they are switched on.
• Constructed of high-quality aluminum and recycled plastic, LED bulbs will not shatter like fluorescent or metal halide bulbs.
• LED lights operate off of direct current with no pulse, which often is the cause of headaches and eyestrain from fluorescent lighting. While research needs to confirm it, this could be an animal welfare enhancement.
• Because they do not emit ultraviolet rays, LED lights are not attractive to flies and many other bugs.
The major drawback of LED lighting is the up-front cost, which can be two to three times that of alternative lighting options. However, Janni points out that many producers have secured energy rebates from their utility companies as an incentive for installing the more energy-efficient LED option. That was the case for the Petersens, who also were able to garner additional funding through a USDA EQIP (Environmental Quality Incentives Program) grant.
Janni advises researching all of these options and doing one"s homework on LED suppliers as well. "Unfortunately, there are some sub-standard LED products on the market, so it is important to work with a trusted and knowledgeable supplier who will back the products with a warranty of at least five years," he suggests.
Currently, Petersen estimates that on energy savings alone, his enterprise will recapture the $7,000 investment in LED lighting in approximately 5.6 years. By factoring in utility rebates and the EQIP cost share, that breakeven drops to 3.8 years. Increased milk production would further accelerate the pay-off. "Our primary goal was energy conservation," he says, "but if we can realize additional benefits along with it, then it makes the change even more advantageous. It"s an improvement about which I am becoming more enthused all the time."
Sidebar: More milk, too?
Another exciting aspect of installing LED lighting on dairies is the possibility that it could boost milk production. An Oklahoma State University study published last year split a freestall barn in half and divided a group of 500 Holsteins into two groups — one housed in free-stalls under metal halide lights, the other under LED lights. The surprising results: the LED group produced 6 pounds more milk per day.
The researchers who conducted the study aren"t sure whether the increase was due to cows eating more in the brighter conditions, a hormonal effect, or something else. They also are quick to point out that the trial was limited in scope and needs to be replicated on a larger scale to confirm the results. Still, the potential is promising.
Iowa dairy producer David Petersen, who has installed LED lighting, says he is hesitant to weigh in on milk production differences in his herd until the cows have lived in the LED-illuminated environment for a full year, but is intrigued by the possibility of more milk.