January 9, 2017
By: Lloyd Alter
For a long time this TreeHugger was dismissive of vertical farms, agreeing with Adam Stein who wrote that “Using urban real estate in this manner is incredibly wasteful: bad for the economy and bad for the environment. Local food has its merits, but that’s what New Jersey is for.” As recently as a year ago I was calling them wrong on so many levels.
I was wrong.
At the time, almost eight years ago, when we were dissing vertical farms, it was all about visions of new towers in the city, expensive purpose-built structures that I thought were “good drawings, lots of ideas and great fun” but unrealistic, like Vincent Callebaut’s silly Farmscrapers. I was probably right about that, and Adam Stein was right about New Jersey.
The vertical farm that is changing the way we think about vertical farms is in fact in Newark, New Jersey, inside an existing old steel warehouse that has been converted rather than an expensive new facility. It’s called Aerofarms, and Margaret wrote 关于 it when it was proposed two years ago.
When TreeHugger friends Philip and Hank complained about the economics of vertical farms, they noted in EcoGeek:
A farmer can expect his land to be worth roughly $1 per square foot…if it’s good, fertile land. The owner of a skyscraper, on the other hand, can expect to pay more than 200 times that per square foot of his building. And that’s just the cost of construction. Factor in the costs of electricity to pump water throughout the thing and keep the plants bathed in artificial sunlight all day, and you’ve got an inefficient mess. Just looking at those numbers, you need two things to happen in order for vertical farms to make sense. You need the price of food to increase 100 fold over today’s prices, and you need the productivity of vertical farms to increase 100 fold over traditional farms. Neither of those things will ever happen.
But if you read Ian Frazier’s wonderful 文章 in the New Yorker, The Vertical Farm, you find that they did actually solve most of those problems at Aerofarms. The cost of the real estate per square foot is irrelevant, because the plants are stacked in trays eight high.
They are set in a repurposed old building in a city that’s very close to New York city but has relatively cheap industrial real estate.
Then there are the changes in technology. LED lighting has evolved to where they can tune the lighting to the exact colours that the plants need for photosynthesis, saving huge amounts of electricity and excess heat over the broad fluorescents and metal halide lights of a decade ago.
And water? Using technology developed by inventor Ed Harwood of Ithaca, New York, the plants are suspended in a fabric made from old pop bottles. Frazier writes:
The fabric is a thin white fleece that holds the seeds as they germinate, then keeps the plants upright as they mature. The roots extend below the cloth, where they are available to the water-and-nutrients spray.
The air in the building is rich in CO2, the lighting is just right, the nutrients are fed at just the right rate using seventy percent less water, and it is all carefully monitored by computers and technicians.
… each plant grows at the pinnacle of a trembling heap of tightly focussed and hypersensitive data. The temperature, humidity, and CO2 content of the air; the nutrient solution, pH, and electro-conductivity of the water; the plant growth rate, the shape and size and complexion of the leaves—all these factors and many others are tracked on a second-by-second basis. AeroFarms’ micro-, macro-, and molecular biologists and other plant scientists overseeing the operation receive alerts on their phones if anything goes awry. A few even have phone apps through which they can adjust the functioning of the vertical farm remotely.
Ten years ago, we showed visions of people in lab coats walking around plants in soil many storeys up in the air. The reality today is very different, using rehabilitated buildings, high density planting, almost no water and LED lighting. It makes so much more sense. Ian Frazier concludes:
I thought of the tenderness of the greens this device produces—a natural simplicity elicited mainly from water and air by high-tech artifice of the most complicated and concentrated kind. It seemed a long way to go for salad. But if it works, as it indeed appears to, who knows what might come of it when we’re nine billion humans on a baking, thirsting globe?
A decade ago we called them pie in the sky, and thought nothing would come of it. Today, I am not so sure. I think I have to eat my words, along with some Aerofarms baby greens the next time I am in New York.
Read the original story at www.treehugger.com.