LED for plant growth

 

Plants require a radiation / photon flux in special wavelenghts which is effective for photosynthesis.
The light we need for plant growth is from the wavelength regions around 450 nm and 660 nm.
chloropyll absorption
chloropyll absorption
 
Therefore we used in the past  for artificial exposure of plants  discharge lamps (HPS/HID), because these have had a high efficiency in the conversion of electric energy into light and a high average life.
 
For a conventional horticultural lantern with sodium vapor lamp - nominal power, e.g. 400 watts and a system consumption of 440 watts - 71-75% of the energy used is converted into heat and only 25-30% in light. In the emitted light spectrum 40% are unused  by the plant, which results in only a power of about 75 watts being available for the assimilation.
 
This results in the great advantages with regard to energy saving by means of LED technology. In the case of the efficient control / supply of current high-power LEDs, considerable proportions of about 60% are also converted into heat, but wavelengths required for the plants can be generated. Therefore, an LED-based plant light for the production of 75 watts of usable light requires just under 200 watts. This results in an energy saving of more than 50% when using modern LED plant luminaires compared to conventional systems.
Spectrum Osram Plantastar
Spectrum Osram Plantastar

 

These circumstances also explain why energy-saving growth-promoting plant lighting is not possible with regular white LEDs. Illumination with white LEDs is useful only for sales areas or decorative installations for the human eye.

 

PlantStar 400 LED professional
PlantStar 400 LED professional