urbanfarming

MIT’s Incubator-grown Plants Might Hold Key to Food Crisis

(Wired UK, October 2014. Photo: Chris Crisman)

Even amid the creative genius and goofy playfulness of MIT’s Media Lab near Boston — where giant inflatable sharks dangle from ceilings, workbenches are populated by unblinking robot heads and skinny scientists with mutton chops and Hawaiian shirts pay rapt attention to indecipherable whiteboard scribbles — Caleb Harper is an oddball. While his coworkers develop artificial –intelligence, smart prosthetics, folding cars and 3D neural-imaging systems, Harper is growing lettuce. In the past year, he has transformed a small lounge outside his fifth-floor lab into a high-tech garden worthy of a sci-fi film. Species of lettuce — as well as broccoli, tomatoes and basil — grow in mid-air, bathed in blue and red LED lights, their ghostly white roots dangling like jellyfish. They are stacked in shelves on an exterior glass wall, seven metres long and 2.5 metres high, meant to resemble the exterior of an office building. If Harper and his team get their way, entire city districts will one day look like this, a living and edible garden.

“I believe there’s the possibility that we can change the world and change the food system,” says Harper, a tall and stocky 34-year-old in a blue shirt and cowboy boots. “The potential for urban farming is huge. And it’s not all bullshit.” Urban farming has begun to shift from its look-what-we-can-do phase of growing salads and vegetables on industrial rooftops and in empty city spaces, to a new wave of innovation that is being led by thinkers — and makers — like Harper. As founder of the year-old CityFARM project at MIT, Harper is figuring out how to use data science to optimise crop yields, deploy networked sensors to “listen” to a plant’s water, nutrient and carbon needs, and deliver optimal light wavelengths — not just for photosynthesis but to change the flavour of foods. And he hopes to bolt his towering plantations on to the buildings in which we live and work.

His system promises to change the economics of industrial agriculture and to lessen its burden on the environment. By measuring and controlling light, moisture and nutrients, Harper says he can cut water consumption by 98 per cent compared to conventional agriculture; quadruple the growth speed of vegetables; completely eliminate chemical fertilisers and -pesticides; and double the nutrient density and flavour of his crops.

Consider the problem of food. By the time it reaches our tables, it has often travelled thousands of kilometres. Kevin Frediani, the head of sustainable land use at Bicton College, an agricultural teaching centre in Devon, has noted that 24 countries supply 90 per cent of the fruit and vegetables to the UK (British farmers provide 23 per cent of that figure). He has estimated that a head of lettuce grown in Spain and trucked to the UK roughly has a 1.5kg carbon footprint. But if grown in the UK in a greenhouse, its footprint is around 1.8kg: “We just don’t have the light, and glass is extremely inefficient at keeping the heat in,” Frediani says. But, he adds, that lettuce grown in an insulated building, and using the heat from lights, can trim that carbon load down to 0.25kg. (Frediani knows his stuff: as the former head of plants and gardens at Paignton Zoo, he instituted a vertical growing facility in 2008 to help feed the animals.) If the new agtech farmers can make their methods scalable, they will produce cheaper, fresher and more nutritious food, cut the hundreds of millions of tonnes of greenhouse gases emitted through transportation (packing, moving, storing and sorting produce uses four times as much energy as growing it does) and offset a food crisis.

The UN predicts the world’s population will grow by 2.5 billion by 2050 and 80 per cent will live in cities. Today, 80 per cent of the land suitable for growing food is already in use, and heatwaves and floods have laid waste to crops and driven food prices higher. Innovative entrepreneurs and green-minded technologists have turned to the cities themselves as a solution. Food can be raised everywhere, from skyscrapers to old bomb shelters.

The fast-growing agtech movement encompasses greenhouse growers and LED-light developers such as the giant Philips Electronics, which has its own horticultural lighting unit. Its enthusiasts specialise in shipping-container farms, systems management, microclimates, aeroponics, aquaponics, hydroponics, rainwater capture and micro-turbines that harness storm run-off for energy production. But indoor farming has not yet proved scalable. Energy use has been the biggest challenge. The wildly touted VertiCrop rooftop hydroponic system in Vancouver (named a best invention of 2012 byTime) went belly-up because it used too much energy. “There is a lot of lying and smoke and mirrors and over-claiming in the field,” says Harper, who grew up on a Texas ranch and whose father was a grocer. “That has led to venture-capital misuse and big and small companies going bankrupt.”

Harper believes his system can cut energy consumption by 80 per cent. And unlike industrial agriculture, which fiercely guards its seed patents and farming techniques, it will be open-source. He plans to give it to whoever wants it, much as MIT’s Fab Labs did with fabrication laser cutters and 3D printers, building them and gifting them to labs around the world. “They created a network of makers and I see this as a potential maker movement for growers,” says Harper.

One day in June, Harper is holding a small cardboard cloud, the kind of thing you might find in a children’s toy box. He’s standing in front of a tray of buttercrunch lettuce lit by a networked red and blue LED. He has rigged a PlayStation camera that tracks body movement. When he passes the cloud in front of the camera, it reads as a cloudy day and the lights brighten. “I could take weather data and write up some kind of algorithm to control the lights,” he says. “But it would never predict when a cloud will come or a rainy day. So we’re aiming for an environment that’s a bit more responsive.”

Against the glass wall, Harper has created what resembles a surgical clean room, using an erector set of AD20 aluminium beams and Plexiglas. Inside, he is growing about 50 plants in rows stacked as high as a metre above his head. Some are growing in shallow water; some have their roots exposed and are regularly misted with nutrients.

By themselves, these methods are not unique: small greenhouses have used them for years. What’s innovative is the use of LED lighting — meaning the specific red and blue parts of the spectrum that produce photosynthesis — and the level of control Harper has. The room is filled with sensors to monitor the atmosphere and temperature and feed back the data. “Over time the room will become more and more intelligent,” he says.

He has also tagged each plant in order to track its growth. “Right now, there is no solid reporting on any of this, only a lot of false claims, or no reporting at all,” Harper says. “There are a lot of black-box concepts out there and no one knows how they work or if they really do this.”

His goal is to produce on-demand food in much the same way that Amazon offers goods for same-day delivery. Instead of someone picking a green tomato in Holland in the summer, or Spain in winter, with immature nutrients and a lack of flavour, and shipping it hundreds of kilometres, then gassing it with carbon dioxide so it turns red, you order your tomato and it’s picked a few streets away and delivered to you fresh. “It’s immediate,” Harper says, “No nutrient density or flavour loss in the food chain.”

His biggest problem at the moment is light. He uses both the Sun through the window and web-enabled LED lights, made by a Swedish startup, Heliospectra. If he’s to scale his farm on to the skin of office buildings, it would be efficient for the Sun to do its part. “Plants only use ten per cent of the light spectrum and the rest of it is just heating up this room, just like in a greenhouse,” Harper says. “So now I have to cool the room with more energy and that’s screwing up my energy equation. So there’s a real open question: is sunlight valuable?”

In traditional greenhouses, the doors are opened to cool things down and release built-up humidity — ut this also lets in unwanted insects and fungus. The teams at Heliospectra and Philips think the Sun is old school. In fact, most of the technological disruption in agtech is coming from lighting companies. Heliospectra supplies its lights to greenhouses as well as academics studying plant-biomass increase, flowering time and flavour density. Nasa uses its lights to grow food at its simulated Mars mission in Hawaii. The light is an LED board with an inbuilt computer. “You can send a signal from the plant on how it’s doing and the plant sends back what wavelength and colour it’s using and how it’s being saturated,” says Heliospectra COO Christopher Steele from his office in Gothenburg. For instance, blue light on basil is not ideal for its growth or flavour, Steele says. Applying a uniform mixture of light is also something the Sun doesn’t do, thanks to clouds and the Earth’s rotation. “We can prevent leaves from being spotted and create a great-looking and great-tasting plant,” adds the company’s CEO, Staffan Hillberg.

At £4,400 apiece, the systems aren’t cheap, but there’s enormous market opportunity. Today there are an estimated 55 million lights in use in greenhouses. “They replace bulbs or lumineers every one to five years,” says Hillberg. “So it’s a big deal.”

Plants prefer LED lights to sunlight. Because LEDs can be placed overhead, plants don’t expend energy growing upwards and developing stalks, and can grow outwards into leafier material. At Green Sense Farms, the largest indoor vertical farm in the world, based 50km outside Chicago, the company uses 7,000 LEDs in two grow rooms. “The lettuces are more intensely flavoured and crisp,” says CEO Robert Colangelo. “We use ten lights per tub and we have 840 tubs. We can generate 150 head per tub every 30 days.”