The Department of Energy estimates LED lighting should reduce overall U.S. energy consumption for lighting by 29% by the year 2025.

LED circuit diagramThe Facts About Indoor Growing with LED Lighting

Overview

LED lights have been utilized in specialized horticulture since the early nineties.  NASA first introduced the idea of using LEDs for plant production in space and they were presented to horticulturists as a promising new technology that could effectively and efficiently replace high intensity discharge (HID) lights.  To date, LED lights have failed to meet horticulturists' expectations.  Wispy flower growth instead of the robust density of a healthy, thriving plant has been common.  This result is not the fault of LED technology, but rather due to poorly designed and manufactured products.   What makes a good LED grow light is a combination of light intensity and a correct balance of light spectrum.  Stealth Grow LEDs solve both these problems.  To understand this, and to comprehend the revolution that Stealth Grow products represent, it is first necessary to have a basic understanding of how an LED light works.

A light emitting diode (LED) is essentially a silicon wrapped aluminum chip, which is impregnated with an anode and a cathode.  Electric current is passed through the chip and energy, called electro luminescence, is released.

LED bulbs emit light at a particular wavelength that is specified by a number represented in nanometers (nm).  These numbers are found in the photosynthetic active radiation (PAR) zone between 400nm and 700nm (this is the visible light spectrum).  LED bulbs are identified by their peak nm intensity but may emit light of both higher and lower frequencies.  For example, if a LED chip is rated at 660nm, it will peak at that intensity but will still cover wavelengths near 640nm and 680nm.  LED chips can be used to produce any wavelength of light

Recent advancements made by LED companies, most notably Cree, have made Hi-power LEDs (HPLED) that can be driven at hundreds of milliamps (mA) (vs. tens of mA for other LEDs), some with more than one ampere of current, and emit large amounts of light.  The vast majority of LED grow light companies still use relatively primitive chip technology.  These chips are far less expensive and emit significantly less energy than the Cree chips used in Stealth Grow light panels.

LED Intensity Measurements

The 1000 watt HPS light has, typically, 140,000 lumens.  It makes no sense however, to compare this number to the number of lumens emitted by an LED.  Lumen is a measure of a light's visible brightness.  The brightest light is emitted in the yellow, green and orange spectrums of light.  This spectrum is the least absorbed in the Photosynthetic Active Radiation (PAR) zone.  Therefore the largest portion of those impressive 140,000 lumens from an HID light is wasted!  While the lumen measurement of LEDs appears less than a 1000 watt HPS, Stealth Grow LEDs actually emit a much brighter light in the plant's usable red and blue spectrum.

Stealth Grow LED light spectrum comparison

2 & 3-watt high-power LED chips are what give Stealth Grow lights their spectacular intensity. While most LED grow light companies use the weaker and less expensive single watt LED chip, we have spared no expense to bring you the highest quality LED grow light available.  Our goal to supply commercial growers with the brightest light possible so that they can produce the yields they have come to expect with a 1000-watt HPS.

Light Spectrum and Absorption

The reason the majority of the market uses the 1000watt HPS light is because it is the highest level of intensity available to supply plant's active photosynthetic needs.  Much of that intensity is not used by plants and is thus wasted as electricity and heat.  Below is a chart that explains the spectrum nanometer wavelength needed for plant growth:

200-280nm UVC ultraviolet range, which is highly toxic and extremely harmful to plants.
280-315nm Includes harmful UVB ultraviolet light, which causes plant colors to fade.
315-380nm Range of UVA ultraviolet light that is neither harmful nor beneficial to plant growth.
380-400nm Start of visible light spectrum.  Process of chlorophyll absorption begins.  UV protected plastics ideally block out any light below this range.
400-520nm This range includes violet, blue, and green bands.  Peak absorption by chlorophyll occurs, and a strong influence on photosynthesis (promotes vegetative growth.)
520-610nm This range includes the green, yellow, and orange bands and has less absorption by pigments.
610-720nm This is the red band.  Large amounts of absorption by chlorophyll occur, and most significant influence on photosynthesis (promotes budding and flowering.)
720-1000nm There is little absorption by chlorophyll here.  Flowering and germination is influenced.  At the high end of the band is infrared, which is heat.
1000+ Totally infrared range.  All energy absorbed at this point is converted to heat.

 

The peak lumen output for a 1000-watt HPS light is between 530-580nm.  While this is an impressive number of lumens, it is ultimately energy wasted.  Using both the PAR values and the relative intensity levels of an HPS in those zones, we can dial in on the ideal ratio of blue, red, deep red and full spectrum light.   Blue light is needed for vegetative growth while red light, particularly deep red in the range of 660, is essential for optimal flower development.  When you combine the ideal spectrum range with 2-watt chip intensity, the result is the best LED grow light panels on the market today!