Could vertical farming be the future?

“November, December, January and February are really dark,” Bugbee said. “Plants aren’t limited by the temperature, they’re limited by the light.” High-pressure sodium lights may be a reasonable stand-in for sunlight to maintain plant growth,  he said, but the electric bill is enormous. “Boy have a lot of people gone bankrupt trying hydroponic greenhouses for that reason.”

Nevertheless,  greenhouses such as Arizona’s 265-acre Eurofresh Farms are thriving with their hydroponic tomatoes and seedless cucumbers. Gene Giacomelli, Director of the Controlled Environment Agriculture Program at the University of Arizona in Tucson, said questions of safety, quality and sustainability are pushing agriculture in a host of other directions, including Despommier’s vertical farming idea. “He’s one extreme – a very good one,” Giacomelli said.

Several years ago, Giacomelli and collaborators in Arizona explored another extreme when they won a contract to design and build a growth chamber within a new building at Antarctica’s Amundsen-Scott Research Station. The chamber can be tweaked remotely by scientists back in Arizona but is now largely managed by volunteers at the station.

Besides supplying some much-needed color and light for the research station’s residents during Antarctica’s bleak and bitterly cold winter months, the indoor chamber has yielded a range of crunchy greens, tomatoes, cucumbers, hot and sweet peppers and even cantaloupe. Next year, a student will try to grow watermelon in what is arguably the worlds’ most inhospitable place for a garden. Remarkably, the plot has produced about two-thirds of what top greenhouses in North America can deliver.

“I like to say that we can grow any plant anywhere and any time, but for a price,” Giacomelli said. The catch in Antarctica is that electricity  for the lights and pumps has inflated the cost to about $50 per pound of fresh vegetables . “Now, the local person at the supermarket would say you’re crazy for spending that much money on vegetables,” he said. “But you give that number to NASA and they’d say, ‘Wow, that’s a good number.’”

Transportation costs
Back on Earth, Despommier said urban farms could defray some of their own expense by significantly cutting transportation costs. And as the local food movement gains in popularity with environmentally conscious consumers, he said, what could be more local than vertical farming? Despite a lack of major technological advances, the effort also stands to benefit from small but steady improvements in hydroponics and automated systems to control temperature, humidity and nutrient delivery, according to Giacomelli.

To curb the excessive reliance on electricity, Giacomelli’s own group is planning to experiment with fiber-optic tubes called solar pipes that can capture sunlight from the Antarctic growth chamber’s roof. Meanwhile, Utah State University researchers have developed a clear piece of curved polyethylene that can retain heat in the ground and extend the growing season by up to four months for summer squash and tomatoes.

As for keeping up with global food demand by growing crops such as rice and wheat,  “we’re going to have to get better at farming marginal lands,” Bugbee said, “but it’s still going to be done outside because the sunlight is so cheap — well, free — and the sunlight levels are so high in the summer.”

He agrees that some farming will move toward more controlled environments, especially for high-value crops like fresh herbs that otherwise would be difficult to supply year-round. “Chefs will pay a lot for fresh basil,” Bugbee said, “but we’re not going to feed the world with that.”

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