Lighting plant factory put into production LED agriculture era is coming

Japan's Mirai Company (Headquarters: Tokyo) has built an artificial light plant factory that uses all LEDs for lighting in the city of Taga, Miyagi Prefecture. According to the company, this is the "biggest global" plant factory that uses LED lighting. It can produce 10,000 lettuce per day.

Mirai transformed the existing building in the Miyagi Futuristic Industrial Park at the Sony Sendai Technology Center into a plant factory. As one of the funded businesses of the Tohoku Economic and Industrial Bureau of the Ministry of Economy, Trade and Industry, Mirai has conducted an empirical experiment with GE Japan on the theme of development of cultivation environment technology and development of LED lighting suitable for plant factories. The design, construction and cultivation of the entire plant are under the responsibility of the Kashima Construction Company of Japan.

The biggest feature of the plant is the use of GE's LED lighting for plant factories in Japan, which uses a technology that evenly disperses highly directional LED light and illuminates different wavelengths of light depending on the growth stage of the plant. For example, in the early stages after exiting the nursery, light white light mixed with white and red LED light sources is illuminated to promote photosynthesis. The reddish light from the LED illumination with the red-blue LED source is then illuminated to promote the growth of the leaves and rhizomes. Near the harvest, white light is again illuminated to promote photosynthesis. With this method, not only is the power consumption reduced by 40%, but the same area is increased by 50% compared to when only fluorescent lamps are used. In addition, Mirai did not disclose specific technologies related to the wavelength of LED illumination.

In order to use buildings with a ceiling of up to 7m, a 15-layer cultivation frame of 6m height was developed. Not only the lighting fixture and the nutrient solution circulation system are integrated and the function is improved, but also the cost is reduced by using measures such as general-purpose cultivation frame members. In addition, Kashima Construction has also introduced the cultivation environment simulation technology, using the technology that the company has cultivated in the plant factory construction process. According to the company's introduction, in order to avoid significant differences in the temperature, air volume and illuminance of the multi-layer cultivation frame in the height direction, this calculation was repeated and the layout of the air conditioner and equipment was designed.

Through the use of LED lighting and 15-layer cultivation racks, the yield per unit area has been increased, and the benefits of plant factories have been improved. According to Mirai, the current retail price of lettuce is about 200 yen. Although the company did not disclose the wholesale price, it said that “vanillas and other open-air cultivations are not much different, and sometimes even cheaper in plant factories. The average price of lettuce and other vegetables is higher than that of open-air cultivation, but it meets open-air lettuce. When the price rises, the two will be basically flat" (Mirai represents the director of the board of directors, Maji, Shimamura).

At present, the plant is planting six kinds of leafy vegetables such as erect lettuce, chicory, lettuce, lettuce and cress, and the time from sowing to harvesting is 33 to 35 days. The plant was commissioned in early May 2014 and will be available on June 20. The cultivated vegetables have begun to be sold in local supermarkets. The plant will be officially put into operation in the summer of 2014, with annual sales targets of hundreds of millions of yen. Companies such as Mirai also intend to use the technology experience gained to export plant factories.

Edit: Cedar