A light emitting diode (LED) is a light source from a semiconductor, first observed in 1927 and was made into a practical light source by Nick Holonyak in 1962. LED lighting break threw have been coming in strong, especially in the last few years. There is a lot more to know about a LED now. You would be amazed.

LED Compared To HID Lighting

LED is 70% Cooler

All HID lights contain a mixture of gasses within the glass enclosure. The internal temperature and pressure gets quite extreme. LED lights, on the other hand, does not use  gas, operating under extreme pressures and temperatures. In contrast LED lights contain a solid state lighting element, eliminating several risk factors associated with high pressure gases. Led is 70% cooler than HID lighting. This means you can place LED lights in between, on the sides of as well as on top of plants. This places more light where it is needed, as well as reducing the space requirements.

LED Emits 75% More Usable PAR Light

HID lights are mostly suboptimal from the perspective of a plant. Plants only respond positively to certain wavelengths within the global color spectrum.

Less than 25% of the power consumed by HID lights is Par light devoted to plant growth. By contrast, 100% of light emitted from a properly designed LED is usable by plants.

LED is Placed 10 Times Closer to Plants

You must also know how close you can apply a particular light bulb. The farther away a bulb is from the plant, the less growth light will reach it.This is important. A HID bulb needs to be almost 3 feet from the plants while a LED can be placed as close as 3 inches away. The reason being heat and UV light radiation. UV will burn a plant just as it burns our skin at the beach. LED has no UV. It also runs much cooler.

The Physics Behind LED Lighting

When a LED is turned on, electrons are able to recombine with holes within the device, releasing energy in the form of photons. This effect is called electroluminescence. The wavelength of the light  is determined by the energy band gap of the semiconductor. With a LED system you can produce the color of light needed in any plant development stage and no more. Therefor the Watts consumed are in the needed range and no more. This fact makes the LED lighting more efficient than the deseptive “lumens per Watt” numbers. Be sure to read Understanding Watts Lumins, Lux Par. The differences are essential to understand if you would like to be informed about horticultural lighting needs.

Header images courtesy of : Research Manager: Dr Titta Kotilainen, of  Valoya Findland