The powerful tsunamis and earthquakes of 2011 hit Miyagi, Japan was where Shigeharu Shimamura worked as he decided to turn a former Sony Corporation semiconductor factory into what is thought to be the world’s largest LED lit indoor farm. The facility is located in Tagajo, Miyagi Prefecture, in eastern Japan 58 miles (94 km) northeast of Fukishima and has 17,500 LEDs spread over a farm half the size of a football pitch, some 25,000 sq ft and 18 cultivation racks with crops up to 16 levels high.
The purple lighting mimics night time while the more white spectrum lighting, just like the Tall Trees LED are adjusted slowly over the entire day to mimic the sun moving throughout the sky. See the GE lights here.
‘We want to achieve the best combination of photosynthesis during the day and breathing at night by controlling the lighting and the environment.’
The special LED fixtures were developed by GE and emit a perfect spectrum for plant growth and the plant opened in July 2014 and is producing 10,000 lettuce per day. The GE LEDs were tuned to emit the optimal spectrum for growth, according to TreeHugger.com; it doesn’t say whether the light formula is particular to the variety of lettuce being grown. “I knew how to grow good vegetables biologically and I wanted to integrate that knowledge with hardware to make things happen,” Shimamura says. The concept took off in 2011, when GE approached Shimamura with an idea for using advanced LED lights to illuminate the farm.
Shimamura can control every aspect of the light, day and night to slow or accelerate growth so that he can grow vitamin rich lettuce 2.5 times faster than the equivalent outdoor farm and the discarded produce is down from 50% to only 10% so all in all the productivity has been increased 100 fold. Then by controlling the temperature, humidity and irrigation perfectly he has cut the use of water to just 1% of what an outdoor farm uses, amazing.
“What we need to do is not just setting up more days and nights,” he says. “We want to achieve the best combination of photosynthesis during the day and breathing at night by controlling the lighting and the environment.”
Shimamura was into indoor farming very early in his career, starting by visiting the ‘vegetable factory’ in 1985 at the World Fair situated in Tsukuba. He went on to study plant physiology at the Tokyo University of Agriculture then in 2004 he started up the indoor farming company Mirai which in Japanese means ‘future’.
These LED lights consume around 40% less electricity than the already lean CFL’s. GE used their own technology to make the lights thin for racks whilst still providing uniform light and maintain working within high humidity grow areas. ‘That way, we can put in more growing racks and increase productivity dramatically,’ said Tomoaki Kimura, country manager for GE Lighting Japan. Mirai and GE are already working on ‘plant factories’ in Hong Kong and the Far East of Russia and the team are keen to help solve food shortages in the world.