LED Horticultural Lighting
LED lights for promoting healthy plant growth. These lamps provide light offering the best growth characteristics while minimizing energy use.
Item ID: 621
Greenhouse and Nursery products are a big business. Oregon's five top producing counties alone had gross sales of $627 million in 2012 while in WA state nursery and greenhouse products ranked as the 8th largest agricultural commodity with sales of $304 million. Greenhouses allow for year-around cultivation of vegetable crops with LED lighting seen as one of the biggest advances in horticultural lighting in decades. Conventional high intensity discharge (HID) or fluorescent lights typically used in greenhouses and hydroponic systems were not designed to meet the unique needs of crops as they are engineered for general illumination rather than photosynthesis. HID lamps waste more than 50% of the energy they consume. This inefficiency costs large greenhouse facilities millions of dollars in electrical bills annually. In contrast, LED solutions can be custom-designed to meet plants’ specific requirements, increase production, and improve quality.
LED grow light systems can be tuned to give varying spectral outputs, allowing agricultural scientists and plant growers full control over the light with the ability to optimize or tune their light source for growing either agricultural products or flowers. Output can even be modified over a growth period with no energy waste due to supply of nonproductive wavelengths (Morrow, 2008). LED light sources can be digitally and spectrally controlled to replace conventional lighting systems or be used as an energy-efficient supplement.
A major advantage of LEDs is the minimal amount of heat generated. Cooling requirements are reduced and lamps can be operated in closer proximity to plants. Reductions in heat emitted allow for a greater degree of control over the climate in a greenhouse. In addition to spectrum options, LED grow lights are available in varying lengths while also offering the choice of precision beam angles to deliver light exactly where it is needed. Manufacturers claim 30-50% savings over traditional HID or fluorescent grow light systems.
Manufacturer's Energy Savings Claims:
Savings Range: From 30% to 70%
Manufacturers often claim 30% to 50% savings from use of LED grow lights over conventional HID or fluorescent grow light systems. As LEDs emit far less heat than HPS or fluorescent lamps, additional energy can be saved through decreased cooling costs. The compact fixtures also save space in both vertical and horizontal growing applications (From BML Horticulture). In addition, LED lights are Eco-Friendly as they contain no Mercury, are directional so require no reflectors, decrease the potential for plant burn and risk of fires, plus their cooler operation results in less watering (Advanced LED Grow Lights). Excessive heat also causes edible plants to lose nutrients and flavor. Some researchers have noted that spectral control stimulates healthy plant growth while significantly reducing the need for plant food or fertilizers (Publitek European Editors, 2012).
Best Estimate of Energy Savings:
"Typical" Savings: 40%
Low and High Energy Savings: 30% to 85%
Energy Savings Reliability: 3 - Limited Assessment
GE Lighting provided an LED lighting system for an urban lettuce farm that produced 10,000 heads daily. The LED lighting was tuned to the lettuce growing cycle with the result of 50% better plant production relative to fluorescent-lit farms along with a 40% reduction in energy use (Wright, 2014). Transportation fuel benefits also occur as the food is grown closer to consumers.
Philips has conducted field tests with growers and has developed "light recipes". A light recipe indicates the light level, spectrum, required uniformity, position, and time to grow a certain crop under selected conditions. They have used their Greenpower LED products with floriculture (cut flowers, potted plants, bedded plants, perennials), for propagation (tissue culture, seedlings, cuttings and young plants); and with vegetables and fruit (high wire vegetables such as tomato and cucumber, leafy vegetables, herbs, and soft fruits). Many case study results are available---one floriculture greenhouse reports that one 35W LED module replaces two fluorescent tubes of 58W each, representing a 65% electricity savings. A Poinsettia producer replaced 150W bulbs with 17W LEDs. GreenSense Farms, an urban farming enterprise, reports using 85% less energy after converting to LEDs. A tomato grower used LED lighting in combination with HID lighting and achieved an energy savings of 35%. Another fruit and vegetable grower states that "with LEDs you get about 1.46 times greater efficiency than with HIDs". LEDs produced an energy savings of 82% to 85% for a strawberry grower when contrasted with incandescent lamps (Philips , 2014).
In some applications, LEDs are used to provide supplemental lighting for greenhouses during the darker months of the year. LED was compared against HPS supplemental lighting used for the production of cut gerbera. The LED lighting reduced energy use by 40% while providing 16% more marketable flowers (LumiGrow).
Energy Use of Emerging Technology:
Currently no data available.
Currently no data available.
Currently no data available.
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.