February 27, 2015
You have most likely heard that LED grow lights are more efficient than traditional grow lights like HPS, Ceramic Metal Halide and Fluorescent bulbs. And you wonder “is it really possible to save on electricity consumption when using LED grow lights?” The answer is “yes”, and this article would tell you why. Your plants do not use electricity to grow but photons of light. Your focus as a grower should be on providing the right amount of light (measured in a number of photons) of the right quality (spectrum) over the right time and evenly spread over your crop canopy. This can be achieved if you use fixtures that are high quality manufactured and its engineering is backed up by plant knowledge and science. High-intensity discharge lamps (HID) to which high HPS and Metal Halide (MH) lamps belong have a very high operating temperature. A large portion of the energy consumed by HID bulbs goes to the heat radiation (infrared radiation). Infrared photons are not utilized by plants in photosynthesis (except far-red), but they warm up plants and the environment. When using HPS and other traditional lights in a warm climate or simply when you have to install many fixtures per an area, plants can easily be overheated causing you to need additional ventilation. Electricity consumption by fans and air conditioning will add more energy demand to your grow facility. There are other cheaper and beneficial ways to warm up your grow facility such as having a heating system which can be simply turned off without turning off the lights. LEDs are not just a replacement for HPS lights. HPS and other HID lamps cannot be placed close to the plants without burning them. To maintain thermal control in most instances, grow facilities using a large number of traditional lights need to have a very efficient HVAC system and allow for a safe distance between the canopy and the lights. This increases the cost of construction and maintenance additionally increasing electricity requirements. In contrast using LED lights allows growers to use much more economical facilities. Although LED lights, as every electric device, produce heat, theirs operating temperatures are much lower. They also do not emit heat radiation with their light. Therefore, they can be placed in close proximity to the plant canopy saving space and construction costs. Bright doesn’t mean efficient. HPS grow lights appear brighter. This is because they contain a large proportion of green light. Humans see green light about 10 times better than blue or red light. Plants do use green light, but not as efficient as other wavelengths. For plants, a typical HPS bulb spectrum with a high percentage of green and yellow light is a signal that they are shaded by other plants, even if they are not. In such conditions some plants will elongate. Most of the crops grown in this condition will produce less secondary metabolites (chemicals responsible for taste, smell, coloration, disease defence or medical properties of crops). In contrast, LED grow lights offer a varying and, in some cases, adjustable light spectrum, which can promote desired characteristic in your plants and increase benefits in your crops. The light distribution matters. LEDs are constructed to emit light as a beam of light directed down. Traditional grow lights emit light in all directions making them to require hoods and reflectors to direct the light down to the plants. These pieces of equipment add bulk and are not efficient in directing light to the plants  thus indirectly increasing energy consumption. High quality LED grow lights are equipped with secondary optics. This helps to avoid “hot spots” (a concentration of light directly under the middle of a fixture) and distribute light evenly over the growth area. It also assures that photons are delivered directly to your crop. You should always ask for a light plan. Hanging grow lights in the right position and distance will allow your crops to utilize the photons emitted by your grow light to a full extend. Lights do not have to be static. LED grow lights allow high levels of control over the light output thereby providing opportunities to use smart systems like our helioCORE™ control systems  to control your lighting, adjust your light intensity and duration to the changing conditions in your grow facility. Using intelligent lighting control, you can save on energy consumption by using grow lights only when you actually need them and adjusting the light intensity to the momentary requirements of your crops. A recent U.S. Department of Energy (DOE) report examining the energy-saving potential of LED lighting in horticultural applications found that LED Grow lights may offer 24% to 30% reduction in electricity consumption compared to traditional horticultural lighting technologies. The study concluded that if all horticultural lighting today was converted to LED technology, annual horticultural lighting consumption would be reduced to 3.6 TWh (from 5.9 TWh in 2017), thereby representing energy savings of up to 40%, or $240 million. While high quality LEDs lighting costs more initially, it has a significant impact on your growth environment and pays off with a decrease in operation cost such as lower electricity cost, less waste and better yields. Ready to maximize the profit of your grow facility? Contact Us