A Lighting Facts Label for Horticulture
In 2009, the Department of Energy (DOE) created the LED Lighting Facts program to help manufacturers, utilities, and consumers in the early days of LED lighting, when products entered the market with little or no verified information on product performance. The voluntary DOE LED Lighting Facts effort paved the way for the mandatory Federal Trade Commission (FTC) label required for most commercial and residential lighting products (including incandescent, compact fluorescent, and LED light bulbs), which was introduced in 2010. This initiative had a significant impact in advancing the adoption of LED technology in general lighting.
Lighting Facts Label for Commercial & Residential Lighting
Today we are seeing a similar effort for grow lights. Development of a lighting facts label for horticulture is being spearheaded by university researchers that believe there is a need for clarity and consistency in communicating to growers the performance metrics for horticultural lighting products. The objective is to create a label that is easy to read and understand and would aid in the comparison of products from different manufacturers. Researchers have proposed a horticulture lighting facts label that they hope will one day become an industry standard. Information reported on the label is intended to come from measurements taken at certified independent test labs.
Proposed Lighting Facts Label for Horticulture
Key information listed on the label:
- Light Output
Output within the photosynthetic active radiation (PAR) spectrum of 400-700nm is listed at the fixture’s nominal input power, which is also on the label.
- Spectral Power Distribution & Intensity
Many growers have a preference for the spectral composition of the light they need to optimize crop yield and health. The label provides a graph of the normalized photon flux vs. wavelength. It also quantitatively breaks down the light into its spectral components of red, green, blue, UV, far red and infrared. These spectral buckets are reported in units of intensity (umols/m2/sec) with the fixture mounted 2-feet (61cm) over the canopy.
The proposed label displays a graph of the intensity of the light as a function of distance from the center of light (also at the 2-foot mounting height). This information provides insight into the uniformity of intensity on the canopy from a single fixture.
Understanding how efficiently a grow light converts electrical input power to light output obviously has a major impact on the operating costs of a grow operation. The proposed label displays PAR efficiency in umols/joule.
- Color Quality
Although terms such as lumens and color rendering index (CRI) are not important to plants, they can be important to people working in a controlled growing environment. Of particular import, the proposed label lists the light fixture’s CRI, which indicates how accurately humans can see colors reflected from objects they are viewing. There are many grow lights on the market that consist primarily of blue and red LEDs, and it can be very difficult for people to determine plant health under those lights. The closer the CRI is to 100, the more accurately the plant’s colors (and health) can be determined by workers.
The proposed label is currently under review, and the team that created it is collecting feedback from industry stakeholders. Presently there is no requirement for approval of the label from the Department of Energy, so it is currently a voluntary standard. The hope is that once growers see the label on a few lighting products, they will demand its use from all lighting manufacturers. While benefits of the label to growers is clear, a major benefit to serious horticulture lighting manufacturers is as a weapon against low-quality products that overpromise, underdeliver and slow the adoption of new technologies.