From the outside it looks like a tall, metal-clad barn. But step in, through a large airlock designed to keep out the bugs, and a kaleidoscopic scene emerges. A central aisle is flanked by two pairs of towers. Each tower is stacked with a dozen or so trays on which are growing strawberries, kale, red lettuce and coriander. And each tray is bathed in vibrant light of different colours, mostly hues of blue and magenta. Douglas Elder, who is in charge of this artificial Eden, taps some instructions into an app on his mobile phone and, with a short whirr of machinery, a tray of lush, green basil slides out for his inspection.
Mr Elder is product manager for Intelligent Growth Solutions (igs), a “vertical farming” company based at Invergowrie, near Dundee, in Scotland. Each of the nine-metre-high towers in the demonstration unit that he runs occupies barely 40 square metres. But by stacking the trays one on top of another an individual tower provides up to 350 square metres of growing area. Using his phone again, Mr Elder changes the colours and brightness of the 1,000 light-emitting diodes (leds) strung out above each tray. The app can also control the temperature, humidity and ventilation, and the hydroponic system that supplies the plants, growing on various non-soil substrates, with water and nutrients. Armed with his trusty phone, Mr Elder says he can run the farm almost single-handedly.