LED, Lighting Emitting Diode, is the semiconductor component which can transfer the electric energy into light. However, in the process of power transfer, apart from emitting lights, there is lot of power will be converted into thermal energy therefore generating heat.
In general, based on current LED manufacture technology, regarding the LEDs with CRI value of 80-90 Ra, its efficacy will be about 30%-40%. In other words, there is only 30%-40% electric power transferred into light, the rest 60%-70% is transferred into heat. While for...
Lifetime is a critical index for evaluating lighting fixtures. Conventional lighting fixtures are relatively inexpensive, of which the most widely adopted type is the fluorescent light, with only 3000 hours’ longevity. Compared to that, LED lights are normally more costly, but are famous for their long lifetimes, normally over 50000 hours. When it comes to plant growth, a long-life light can greatly save the maintenance cost and help increase profits. This is a key factor for plant factory owners when they choose lighting fixtures.
Before LED lighting technology came to maturity, greenhouses were the major form of artificial plant factories. In greenhouses, temperature condition can be better controlled than plants grown outside, and sunlight is obtained during the day through the transparent plastic. Also, by setting conventional lights in greenhouses, the shortage in sunlight can be covered, and the lighting hours can be extended, thus adjusting the plant’s photoperiodism and finally promoting plant growth and yield.
In traditional greenhouses (Figure.1), the lights are usually placed on the ceiling with quite a distance above the plants. In this...
Compared with the factor ofLED viewing anglewe discussed last time, our topic today–light qualityis a more significant index in terms of which LEDs have a revolutionary advantage over conventional light sources. The emergence and growth of LED technology has stimulated the development of modern agriculture and resulted in many new forms of agriculture, such as vertical farming.
Biologically, plants can perceive light within certain range of wavelength, just as the human eye does. Theluminosity functionis used to describe the human eye’s sensitivity to lights of different wavelengths. Plants also have their own...
In our last post, we talked about the significance of lighting for pant growth in terms of light intensity, photoperiodism and light quality. In plant growth, light intensity is expressed as photosynthetic photon flux density (PPFD). It depends on both the optical design of the fixture and the number of photons emitted by the light source.
So what are the advantages of LEDs over conventional lights in providing sufficient light intensity for plant growth?
Let’s suppose there is a plant growth environment, where the plant is growing in...
