The Advantages of LED
LED-based lighting systems compared to other light sources have a number of advantages in horticulture.
1. The possibility to control the spectral output of the lighting system. Light spectral output can be customized for each specific crop. The output of the light spectrum can be modified during a growth period.
2. LED lighting systems can produce very high light levels. They can be operated very close to plant tissue by those very high light levels. The reason is that they have very little radiant heat output when cooled properly. The efficiency of the lighting system is improved because operating close to the canopy lets most of the light produced to be intercepted by the plant.
3. LEDs have a very long operating life.
4. LEDs turn on and off instantly. They do not require warmup time. LEDs are easily integrated into digital control systems because they are solid-state devices. LED-based lighting systems can be continuously dimmed between zero and maximum Custom spectra and custom programs (for example sunrise and sunset simulations) can be programmed.
5. LED-based lighting systems tend to have significant cost savings over current horticultural lamp types. They have a long operational life. Disposal cost for replacement bulbs is mostly eliminated along with associated labour costs. LEDs can also reduce power use through the ability to operate in close proximity to plant tissue, the ability to optimize the light spectrum for productivity, and optimization of lighting patterns to each crop.
6. LEDs do not contain mercury and do not have glass envelopes or high surface temperatures that can cause injury.
7. They also do not produce damaging ultraviolet wavelengths (unless added for specific needs) as HID lamps do.
8. Because LEDs can be a focused lighting source very close to the plant material, and because they emit only highly absorbed wavelengths, in greenhouses, they should produce much less wasted light that can contribute to light pollution.