Greenhouses typically rely on lighting from high-intensity discharge (HID) fluorescent and halogen lamps, but it is believed that much less electrical power is needed with light emitting diodes (LEDs) to achieve the same or better plant response. Even further, LED lighting promises growers new capabilities of tuned or “customized” light wavelengths, so that the color they emit matches exactly the colors absorbed most efficiently by plant pigments during specific stages of growth. This capability could optimize healthy plant production and possibly accelerate time from seed to retail. In addition, LEDs are more robust and vibration proof and they offer a longer service life than established lighting sources.
Despite the potential for LEDs in the horticulture industry, there are few field studies in the area of plant production. In addition, there is a wide variety of LED lighting on the market with enormous variations in terms of price, proven reliability, and quality. The purpose of the “Improving Energy Efficiency and Crop Production in Controlled Environment” CARD grant, awarded to Outsourced Innovation, is to validate energy and cost savings and demonstrate maintenance of plant quality and growth from the use of LEDs in greenhouses that produce tomatoes and basil.
Figure 1: LED lighting fixture for horticulture applications
Outsourced Innovation will design an LED lighting system (such as Figure 1) and compare it to an HID lighting system, each of which will be installed in a windowless, controlled environment and set up to grow the same number of tomato and basil plants. The research plan addresses energy modeling, load profiling, light performance, and crop production. Results are expected to enable specialty-crop growers in Minnesota working in a controlled crop production environment to understand and transition from traditional lighting to more efficient LEDs and adaptive controls, in particular through programs offered through utility Conservation Improvement Programs.
This CARD project is expected to be completed at the end of June 2015. For more information contact the Division of Energy Resources’ project manager Laura Silver.