In the last decade LED technology has advanced significantly and is now available as an alternative to incandescent bulbs and compact fluorescent lighting (CFL) bulbs for various lighting needs. Numerous studies and field test have resulted in several practical uses for LEDs.
Among the many uses of LEDs is their ability to grow plants indoors without the need for any sunlight. LEDs offer many advantages when it comes to growing various plants indoors. One of the biggest advantages to growing with LEDs as compared to growing with various bulbs is that LEDs consume a fraction of the electricity, as much as 70% less. Another advantage of LEDs is they are near zero heat signature. LED grow lights give off less than 10% of the heat that a high intensity discharge bulb such as high-pressure sodium (HPS) or metal halide (MH) bulbs do. Less energy consumption and less heat go hand in hand as the majority of the wasted electricity in HID systems is given off as heat. If you have ever grown with HID systems, heat is always a byproduct, which must be mitigated by venting and air conditioning systems. After just a few minutes of use a HID bulb becomes extremely hot and will burn the skin if touched and has been known to cause fires. Growing with LEDs eliminates this problem completely as even after being on for 24 hours, the LED grow light is only slightly warm and cool to the touch.
The way LED growlights work is that the individual diodes that are in the light are focused to specific wavelengths of the light spectrum necessary for plant photosynthesis. A light bulb gives off white light, which encompasses all the colors of the visible light spectrum. Plant photosynthesis requires only specific wavelengths of light and all the extra wavelengths that are in white light are wasted. LED grow light diodes have a blend of only the wavelengths that are needed in the correct ratios necessary for photosynthesis. These wavelengths are mainly the reds, oranges and blues in the 580-630nm and 420-470nm ranges. LED grow lights have gone through several iterations and the most effective grow lights now include ultraviolet and infrared diodes as well. The best LED grow lights come from companies that have tested various blends of diodes and formulated optimal diode ratios that best mimic the photosynthetic action radiation necessary for plant growth.
Yet another advantage of LED technology is that LED lights last about 100 times as long as light bulbs and 6-7 times as long as compact fluorescent lights. It is no wonder that the US space agency NASA has been testing LED grow lights to grow food in space as an energy efficient method that will be a key component to man’s survival in space. The first generation of LED grow lights had very low intensity and total output of 10-20 watts. These lights were only powerful enough to grow very simple and small plants. LED grow lights have since evolved into much more intense lights with power output of 100 watts and more which is necessary to grow more complex plants. LED grow lights have truly come of age and indoor growers are finally able to take advantage of this technology to grow green and grow more efficiently than they have ever been able to before.