Traditional indoor greenhouses typically use white light, which is a combination of all colors in a spectrum. A Pinkhouse, on the other hand, is a vertical indoor farm that uses only red and blue light, which give the place a nice pink glow.
Proper lighting is crucial in indoor farms. In order to grow a lot of plants in limited space, the plants have to be stacked and have sufficient lighting. That means each row or shelf of plants in the vertical platform need its own source of light. Multiple sources of light constantly running mean high energy costs.
New research has shown that plants don’t really need light in all the hues of the color spectrum to grow. At Purdue University, researchers led by Cary Mitchell, professor of horticulture and landscape architecture, are studying the use of red and blue light in indoor greenhouses. Pharmaceutical company Caliber Biotherapeutics are already using red and blue lights in a 150,000 square foot indoor farm where they grow plants for clinical and medical use. Caliber’s indoor farming system was designed by EEA Consulting Engineers and grows about 2.2 million plants with red and blue low-energy LED lights.
According to an article on The Salt, the company developed their lights to correctly match the needs of their plants in terms of photosynthesis. Barry Holt of Caliber Biotherapeutics said they get ‘almost 20 percent faster growth rate and save a lot energy.’