NPR: Vertical ‘Pinkhouses:’ The Future Of Urban Farming?
“The idea of taking a skyscraper and turning it into a vertical farming complex is absolutely ridiculous from an energy perspective.”
By Michaeleen Doucleff
May 21, 2013
The idea of taking a skyscraper and turning it into a vertical farming complex is absolutely ridiculous from an energy perspective,” says horticulturist Cary Mitchell of Purdue University, who’s been working on ways to grow plants in space for more than 20 years.
The future of vertical farming, Mitchell thinks, lies not in city skyscrapers, but rather in large warehouses located in the suburbs, where real estate and electricity are cheaper.
And oh, yeah, instead of being traditional greenhouses lit by fluorescent lamps, he says these plant factories will probably be “pinkhouses,” glowing magenta from the mix of blue and red LEDs.
Light is a major problem with vertical farming. When you stack plants on top of each other, the ones at the top shade the ones at the bottom. The only way to get around it is to add artificial light — which is expensive both financially and environmentally.
Vertical farmers can lower the energy bill, Mitchell says, by giving plants only the wavelengths of light they need the most: the blue and red.
“Twenty years ago, research showed that you could grow lettuce in just red light,” Mitchell says. “If you add a little bit of blue, it grows better.”