A farm barges into New York City
If you look out over the Hudson River in New York City this growing season, you might be lucky enough to catch a glimpse of a floating farm; an agricultural wonder that grows cucumbers, tomatoes, yellow squash, green peppers, basil, arugula and a plethora of other greens and vegetables .
The farm—1,300 square feet of greenhouses actually—sits on a 128-foot refurbished 60-year-old barge that travels between its two mooring locations at Pier 84 (West 44th Street) and at West 70th Street from May to late October.
This floating farm is called the “Science Barge” and has been created by environmental engineers and plant biologists at the New York Sun Works Center for Sustainable Engineering, a nonprofit organization that promotes engineering solutions to help cities achieve greater environmental sustainability. The project cost $250,000 to build and was funded by private donations.
The goal of the Science Barge, which was launched on its maiden voyage on the Hudson River in 2007, is to not only prove that vegetables can be grown on a floating barge, said Benjamin Linsley, Sun Works’ public affairs director. “A barge on the river was used to make the project mobile and accessible to as many people as possible,” he said, noting that 10,000 people visited the floating farm last year, including 3,000 schoolchildren.
The ultimate goal, Linsley said, is to prove that fresh vegetables can be grown in a city using sustainable methods that put out zero carbon emissions and use only reclaimed water. The Science Barge is, in essence, a prototype of what the nonprofit company envisions as the future of urban agriculture: commercial rooftop farms.
From the river to the roof
New York City has been home to several successful urban agricultural projects, such as Brooklyn’s East New York Farms, which produces food in community gardens (which the area’s youth sell locally), and Brooklyn’s Red Hook section’s nonprofit Added Value, which grows plants on a 3-acre plot that was previously an abandoned lot. But, on-ground real estate in New York is expensive and limited; perched above the city is untapped real estate: 14,000 acres of usable roof space, an area 10 times more than the total U.S. acreage used for greenhouses today.
While city residents don’t usually have access to rooftops, Sun Works believes there could be room for entrepreneurs (or organizations or communities) to use the roofs of public or retail buildings to create rooftop greenhouses.
Hydroponics greenhouses—like the one used on the Science Barge—are ideal for rooftops since, unlike their soil-based cousins, they are lightweight. Soil-based greenhouses would be labor-intensive to put on top of a rooftop, not to mention cost and regulation-prohibitive.
New York Sun Works’ research shows that there is enough rooftop space in the five boroughs of New York City to house enough hydroponics greenhouses to grow enough vegetables for 10 million people. While it won’t provide the city’s entire food supply it can significantly reduce the need to import certain vegetables and greens from elsewhere.
To feed New York City’s greater metropolitan area takes an area the size of Wyoming, or about 60 million acres. “Our cities grow very little to feed their population and food and water must be shipped hundreds and thousands of miles, consuming processing costs and transportation fuel,” said Linsley.
Combine this growing problem with an increasing world population growth, the high cost of fossil fuels and decreased agricultural lands (particularly if ethanol grown from corn becomes higher in demand), and you have a recipe for an impending food crisis, says Linsley. “Using higher yield food production techniques, like hydroponics, and bringing them to the consumers in the city will help ease the pressure on arable land.”
Many of these vegetables are already being grown hydroponically in greenhouses elsewhere, said Linsley. “Why not eliminate the need to transport these vegetables altogether and put them right where people need them?”
Pie in the sky? Or viable commercial model?
The plan for New York and other urban centers to grow their own food on unused rooftops is not just a pipe dream, but is an economically viable option for growers, say Sun Works’ environmental engineers and plant biologists.
Taking what the organization learned from its experience on the barge, Sun Works will begin construction on a pilot commercial growing operation on top of a warehouse in the Chelsea section of Manhattan this year, and has plans underway for similar commercial-scale greenhouses on rooftops in the U.K. and France. It is estimated that the Manhattan commercial project will cover a rooftop area of about 5,000 square feet, at a cost of $30 to $40 per square foot, to create the greenhouse hydroponics system and sustainable heating and cooling elements. The goal for the Chelsea project is to clear a profit after the capital costs. There is still research and data that needs to be collected on what the market will buy and the eventual yields from a rooftop farm. (Research from the Science Barge’s yields showed it was comparable with averages from other hydroponics growers).
From a scientific point of view, the concept of using the hydroponics system is successful: similar techniques are found in the thriving hydroponics industries in Maine, Arizona, Spain and Holland. “The hydroponics industry already makes decent stable profits,” noted Linsley. “If you can make money elsewhere, why can’t you use the same technology to make money right in an urban center where there will be no cost to transport produce?”
The difference in the Sun Works model is the sustainable technologies used for heating and cooling. The Manhattan commercial rooftop farm will undergo fine-tuning to use waste heat from the building (the heat given off from buildings to be used to heat the greenhouse in the winter), as well as solar, wind, gas or biodiesel. A rooftop farm will use various sustainable energies depending on the circumstance of the building and its rooftop. The warehouse in Chelsea, for example, may not give off enough heat to solely heat by heat recapture (since it is a warehouse), but other occupied buildings will. “Buildings lose an awful lot of heat off the top,” said Linsley. “Recapturing that heat for human use has been difficult because of the high CO2 content. But for plants, it is perfect.”
Sun Works is poised to bring the technology to a variety of other buildings in urban centers and suburban areas. There are many applications, including utilizing the huge flat rooftops on supermarkets and other large retail centers (such as malls or discount stores), schools and educational centers. “It would be an incredible concept to grow food just steps away from where you sell it,” he said. This kind of operation can be managed either by the food chain or by independent farmers in various kinds of arrangements.
At the moment, the majority of the interest surrounding rooftop farms is not coming from commercial growers, but from urban planners and engineers who are looking at what’s coming down the pike in terms of public policy about climate change and what cities can do about it. “These same economics will eventually drive farmers to start looking at different options in a few years’ time as well,” said Linsley. In the U.K., for example, the government is looking at labeling food with “food miles” on packaging; these kinds of regulations will encourage people to purchase more locally-grown foods.
“Food prices are becoming more and more unstable because of energy costs and the increased competition for land,” said Linsley. “If we can move a segment of agriculture that is currently grown in the country into the city, it frees up much-needed space for organic production, [and] for corn for ethanol.”
To view a video stream about the Science Barge, visit YouTube at http://www.youtube.com/watch?v=QDAJOZ25H5Y.