How do LED grow lights work?

Energy-efficient LED grow lights are the lighting of the future of agriculture. They are not only economic in their use but they produce better plants as well, in comparison to all traditional lighting options. In the texts below you can read how the LED grow lights work, how they affect plant growth and what advantages the LED lights have over the thus far most widely used artificial lighting in agriculture - HPS lamps.

What are LEDs and how do they work?
LEDs (Light Emitting Diode) are small electronic components made of two different types of semiconductor material, one having a negative charge, called electrons, and the other having a positive charge, called holes. When voltage is properly applied over an LED, electric current starts to flow through it making electrons and holes start to collide releasing energy in the form of photons, light quanta, in a process called recombination. The first LEDs had relatively low light output and limited selections of colors while modern LEDs have high brightness and come in varieties of colors in visible, infrared and ultraviolet spectral ranges.

A typical LED chip

What are LED grow lights?
As suggested by their name, LED grow lights are luminaires utilizing LED chips in a modern and efficient way to produce light for growing plants. LED grow lights come in many shapes and sizes but as the most essential units of LED grow lights LED chips have most of the effect on the quality of the light, i.e. spectrum (colors) and photon flux (“brightness”) produced. Since LED grow light manufacturers can choose the LEDs they use in their lamps, it is important to understand which kind of LED grow light best fits the specific application. One of the advantages of LED grow lights compared to traditional lighting solutions is the ability to match the light to the needs of plants.

What is the effect of LED grow lights on plants?
Color variations of the LED grow lights are directly connected to the intended purpose – various studies have shown that certain colors influence plant growth, affecting root and flower formation (blue and red light spectra) which practically means that the majority of plant sorts will complete a normal growth cycle if exposed to both blue and red grow lights. Adding other colors to the spectrum, such as green, far-red and deep-blue aids this process by giving plants more information about its environment and overall resulting in higher quality plants (quicker growth, more secondary metabolite accumulation etc). A spectrum that contains all colors is called full spectrum and mostly resembles the sunlight. If it has high proportions of green, the light will appear white to human eyes and while not a crucial factor for plant growth, it does make the work around these lights easier and makes visual inspection of the plants possible. (Read more: Why Is LED Grow Light Purple?)

White and pink LED grow lights (both are full spectrum LED grow lights). Left – Valoya NS1, Right – Valoya AP673L.

How do plants react to different light colors?

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Through research we can determine what the optimal light for plant growth is. It is important to consider that different plants react differently to various light treatments (even different strains of the same plant). Additionally, a plant in its flowering phase may require a different light treatment as opposed to when it is in the vegetative stage. When it comes to the light itself, several parameters can be modified:

Light spectrum (the combination of colors used to produce the light)
Light intensity (typically measured in micromoles, the amount of photons projected onto the plants)
Photoperiod (number of hours a plant is exposed to light within a 24 hour period)
Light uniformity (the degree to which the light is equally distributed across the canopy)

In other words, LED grow lights users need to exercise a tailor-made approach when raising crops due to the fact that each plant species has different needs. In practical terms this means conducting trials before going to large scale production. (Read more: 8 Tips for Setting Up Successful Plant Trials with LED)

An alternative to that is purchasing the LED grow lights from companies that are dedicated to research and provide this data to their customers.

Discover revolutionary advantages of LED grow lights
In its early stages, LED technology was perceived as rather impractical and cost-inefficient. With the newest technology advances LED grow lights production has become cost-effective. Additionally, the range of available LED chip types facilitated the development of a more efficient plant cultivation industry. When set side-by-side with the traditional HPS … click here to read the rest at valoya.com