Light compensation methods include top light compensation, interline light compensation, multi-layer light compensation, etc. Compared with the traditional light source, LED light source lamps are free to be larger in size, shape and power design, flexible in suspension mode and light in weight. A variety of light supplement technology models have been derived, which well meet the practical needs of greenhouse planting methods, crop types and canopy shapes.
Benefit analysis of light supplement
The plant growth lighting technology has made rapid progress, providing many options for greenhouse lighting. Nelson and Bughee (2014) reported the photosynthetic quantum (400~700nm) efficiency and photon emission distribution characteristics of 2 double-sided HPS devices, 5 mogul based HPS devices, 10 LED devices, 3 metal ceramic lamps and 2 fluorescent lamps. The two most efficient LEDs and the two most efficient double-sided HPS devices have almost the same efficiency, ranging from 1.66 to 1.7 μ Mol/J. These four devices are 1.02 higher than the commonly used metal ceramic lamps μ Mol/J efficiency. The efficiency of the best metal ceramic lamp and fluorescent lamp is 1.46 and 0.95 respectively μ mol/J。
greenhouse LED grow light
The author calculated the initial investment cost of each light quantum emitted by the device, and determined that the cost of LED device is 5~10 times that of HPS device. The electricity charge in five years plus the cost of light quantum device per mole is 2. 3 times higher than that of LED device. The analysis results show that the long-term maintenance cost is very small. If the production system has a wide gap space, the unique role of the LED device is to effectively focus the light quanta on special parts, allowing the plant canopy to capture more light quanta. However, the analysis shows that the photon radiation cost of all lighting devices is very high. The lowest lighting system cost can only be achieved when efficient light-emitting devices are combined with effective canopy photon capture.
The progress of lighting technology and fixture efficiency devices has provided many options for greenhouse light supplement, including many LED lamps. Great progress has been made in three aspects of the lamp composition of high intensity discharge (HID) lamps (including high-pressure sodium lamps (HPS) and ceramic metal halide lamps (CMI)), including lamps (electric bulbs), light sources (reflectors) and ballasts. The HPS with electronic ballast and double-sided bulb is 1. 7 times of that of the mogul based HPS device. The analysis includes two parameters, lamp efficiency, that is, measuring the number of photosynthesis photons per joule and the capture efficiency of canopy photosynthetic quantum current (400-700nm), which are part of the photons reaching the plant leaves. The electric energy efficiency of plant growth is measured by the number of photosynthetic photons input per joule.
hemp grow light
The electrical energy efficiency of lamps is usually expressed in terms of human light perception units (lumens per watt) or energy efficiency (radiant watts per watt of electrical input). However, photosynthesis and plant growth are measured by the number of light quantum moles. Therefore, the comparison of light efficiency based on light quantum efficiency should use the unit of quantum quantity of photosynthesis generated by each joule of energy input. This is even more important for LED, because the light color with high electrical efficiency is in the dark red and blue wavelength regions. The low radiant energy capacity of red light quanta allows more photons to transfer energy input per unit (radiant energy is inversely proportional to wavelength, Planck’s equation). On the contrary, the energy efficiency of blue light is 53% higher than that of red light (49% and 32%), but the quantum efficiency of blue light is only 9% higher than that of red light (1. 87/1. 72). There is a misunderstanding about the impact of light quality on plant growth. Many manufacturers claim that light quality promotes plant growth 1 (spectral distribution and monochromatic light ratio).
Analysis on the Advantages of Semiconductor Light Compensation in Greenhouse（二）
Analysis of light compensation technology
Light compensation methods include top light compensation, interline light compensation, multi-layer light compensation, etc. Compared with the traditional light source, LED light source lamps are free to be larger in size, shape and power design, flexible in suspension mode and light in weight. A variety of light supplement technology models have been derived, which well meet the practical needs of greenhouse planting methods, crop types and canopy shapes.
Benefit analysis of light supplement
The plant growth lighting technology has made rapid progress, providing many options for greenhouse lighting. Nelson and Bughee (2014) reported the photosynthetic quantum (400~700nm) efficiency and photon emission distribution characteristics of 2 double-sided HPS devices, 5 mogul based HPS devices, 10 LED devices, 3 metal ceramic lamps and 2 fluorescent lamps. The two most efficient LEDs and the two most efficient double-sided HPS devices have almost the same efficiency, ranging from 1.66 to 1.7 μ Mol/J. These four devices are 1.02 higher than the commonly used metal ceramic lamps μ Mol/J efficiency. The efficiency of the best metal ceramic lamp and fluorescent lamp is 1.46 and 0.95 respectively μ mol/J。
The author calculated the initial investment cost of each light quantum emitted by the device, and determined that the cost of LED device is 5~10 times that of HPS device. The electricity charge in five years plus the cost of light quantum device per mole is 2. 3 times higher than that of LED device. The analysis results show that the long-term maintenance cost is very small. If the production system has a wide gap space, the unique role of the LED device is to effectively focus the light quanta on special parts, allowing the plant canopy to capture more light quanta. However, the analysis shows that the photon radiation cost of all lighting devices is very high. The lowest lighting system cost can only be achieved when efficient light-emitting devices are combined with effective canopy photon capture.
The progress of lighting technology and fixture efficiency devices has provided many options for greenhouse light supplement, including many LED lamps. Great progress has been made in three aspects of the lamp composition of high intensity discharge (HID) lamps (including high-pressure sodium lamps (HPS) and ceramic metal halide lamps (CMI)), including lamps (electric bulbs), light sources (reflectors) and ballasts. The HPS with electronic ballast and double-sided bulb is 1. 7 times of that of the mogul based HPS device. The analysis includes two parameters, lamp efficiency, that is, measuring the number of photosynthesis photons per joule and the capture efficiency of canopy photosynthetic quantum current (400-700nm), which are part of the photons reaching the plant leaves. The electric energy efficiency of plant growth is measured by the number of photosynthetic photons input per joule.
The electrical energy efficiency of lamps is usually expressed in terms of human light perception units (lumens per watt) or energy efficiency (radiant watts per watt of electrical input). However, photosynthesis and plant growth are measured by the number of light quantum moles. Therefore, the comparison of light efficiency based on light quantum efficiency should use the unit of quantum quantity of photosynthesis generated by each joule of energy input. This is even more important for LED, because the light color with high electrical efficiency is in the dark red and blue wavelength regions. The low radiant energy capacity of red light quanta allows more photons to transfer energy input per unit (radiant energy is inversely proportional to wavelength, Planck’s equation). On the contrary, the energy efficiency of blue light is 53% higher than that of red light (49% and 32%), but the quantum efficiency of blue light is only 9% higher than that of red light (1. 87/1. 72). There is a misunderstanding about the impact of light quality on plant growth. Many manufacturers claim that light quality promotes plant growth 1 (spectral distribution and monochromatic light ratio).