From Singapore to Scranton, Pennsylvania, “vertical farms” are promising a new, environmentally friendly way to feed the rapidly swelling populations of cities worldwide.
In March, the world’s largest vertical farm is set to open up shop in Scranton. Built by Green Spirit Farms (GSF) of New Buffalo, Michigan, it will only be a single storey covering 3.25 hectares, but with racks stacked six high it will house 17 million plants. And it is just one of a growing number.
Vertical farms aim to avoid the problems inherent in growing food crops in drought-and-disease-prone fields many hundreds of kilometres from the population centres in which they will be consumed. Instead, Dickson Despommier – an ecologist at Columbia University in New York City who has championed vertical farms since 1999 – suggests that food should be grown year-round in high-rise urban buildings, reducing the need for the carbon-emitting transport of fruit and vegetables.
Proponents see vertical farming as a way to feed a global population that is urbanising fast: 86 per cent of the people in the developed world will live in cities by 2050, the United Nations predicts. It could make food supplies more secure as well, because production can continue even when extreme weather strikes. And as long as farmers are careful to protect their indoor “fields” from pests, vertical farming needs no herbicides or insecticides. They also conserve water far better than earthbound farming.
Today’s LEDs are only about 28 per cent efficient, which keeps the cost of produce high and prevents vertical farms from competing in regions where cheap vegetables are abundant. However, lighting engineers at Philips in the Netherlands have demonstrated LEDs with 68 per cent efficiency, which could dramatically cut costs.
DARPA is using an 18-storey vertical farm in College Station, Texas, to produce genetically modified plants that make proteins useful in vaccines. Adversity also plays its part: the tsunami-sparked nuclear accident in Fukushima, Japan, in 2011 is leading to innovation in vertical farming because much of the region’s irradiated farmland can no longer be used.
About 12% of the 1.05 million square meters (11.3 million square feet) of the 202 story Sky City will be vertical organic farm, parks and open air gardens. It will be 930,000 square feet (86,400 square meters or over 21 acres). The entire Skycity project is to cost about $1.5 billion (9 billion yuan). There will also be 26,880 square meters of indoor park and 8000 meters of open air gardens.
The Sky City has been delayed until about April, 2014 while awaiting full permits. The foundation is being built now and the funding and other aspects of the project are in place.