Research Status and Prospect of Energy-saving Technology of LED Light Source in Plant Factory

LED supplemental lighting system is an indispensable part of plant factory, it is used to improve the light situations indoors and provides radiation that plants needed. Although LEDs energy consumption is reduced by about 50% compared to other artificial light sources, long-term with a large-area usage still brings high costs. In order to reduce the supplemental lighting cost and save energy, we tried to present a comprehensive survey on the subject firstly and summarized the existing energy-saving methods of LED supplemental lighting in plant factory. On this basis, a new system was proposed, on which the canopy area and position at different growth stages of plant were extracted based on machine vision firstly, then a certain number of LEDs directly above the plant would be turned on to avoid light waste in the blank area of cultivation bed. At the same time, the turned-on time and brightness level of LEDs were calculated according to the plant biological characteristics and light situation indoors, so system can give a precise radiation on plant and have a great potential to lower cost and save energy. This research has a promoting effect on the development of plant factory.