Most vertical farm designs depict them as ultra-modern, stylish skyscrapers, 30 to 40 stories tall. Each floor could potentially feature a variety of crops and small livestock. Tanks would house fish and other seafood. Using technology to minimize waste and energy use, and to facilitate recycling, is essential. To that end, they would contain glass walls, large solar panels, high-tech irrigation systems and incinerators that burn waste for energy. A variety of monitoring systems would ensure that energy and water go where they need to go and that temperature controls are carefully maintained.
Water would be carefully distributed through irrigation while any excess water would be collected and recycled. Dew can be collected through evaporation. Sewage, also known as "black water," can be cleaned by algae and plants and made potable. Or it can be treated by filters and made into "gray water," which is sterile and useable for irrigation. Cities dump billions of gallons of gray water into rivers every day.
Methane gas, instead of being allowed to escape into the atmosphere, would be collected. Any excess energy would be sold back to the local energy grid.
Dr. Despommier believes that 150 30-story farms could feed all of New York City. Elegantly designed, these vertical farms would be carefully placed around a city or clustered together in a nearby development (in the case of New York City, possibly on Governor's Island). They would remain unobtrusive, or even pleasant to the eye.
For vertical farming to be possible, experts from a variety of disciplines have to come together, including agriculture, agronomy, civil planning, architecture, engineering, economics and public health. But we're not starting from scratch. Dr. Despommier and others have published studies describing plans for development and implementation of vertical farms. In fact, all of the technology behind vertical farming already exists, though it could take up to 10 years to figure out how to make these technologies work together. Even so, we already grow plants hydroponically (without soil), in extreme environments and on space ships. Biomass, methane collection and waste-water collection are becoming essential tools of conservation.
Some criticize vertical farming because it would eliminate jobs of conventional farmers and those who transport and package their goods. To those critics, one could point out that 95 percent of Americans were farmers before the Industrial Revolution, and this may simply be the next step in that evolution. But it's also the contention of Dr. Despommier that vertical farming would create jobs. Thousands of people would be required to develop, build and maintain these systems. The socioeconomic impact could be immense, especially for those who struggle as subsistence farmers or in abject poverty. In the developing world, the presence of a dependable food supply and improved nutrition would raise standards of living, allow the development of commerce and shift children away from agricultural work and into schools.
Two hurdles remain for vertical farming to become a reality: money and government support. However, Dr. Despommier is already in touch with investors and philanthropists who want to establish a Center for Urban Sustainable Agriculture. With enough investment, the first vertical farm could be up and running (and even profitable) in 15 years, while government support would surely help in their proliferation.
For more information about vertical farming and other related topics, and to watch a video showing a vertical farm design, please check out the links on the next page.