The Greenhouse Effect (This Time It’s Positive)
So we have a vote optimizing the earth battery for sustained charge, and for the best materials to power that charge. The other factor we can consider is optimized dimensions. Ideally, a battery occupies the smallest dimension while providing the greatest power.
When considering the earth battery, one might be surprised to learn that the Netherlands is essentially one of the most streamlined, minute organic batteries one could imagine. Surprisingly, that smaller country is second only to the United States in terms of agricultural exports (in financial terms) from its production of traditional crops, tomatoes, dairy, and flower bulbs. How in the world did such a small country do this? How could this be done by the second most densely populated country in Western Europe, about the size of Maryland or Bhutan, or slightly larger than Haiti?
The secret is that the Dutch manage nature and its forces very well in open farming. But they also use greenhouses on 0.25 percent of their land, which allows the country to be hyperproductive per square foot, eliminate wind damage to crops, increase solar flux, and reduce water evaporation; furthermore, the soil nutrients exist in closed systems, making their reuse simple. Not only do the greenhouses increase crop yields and decrease energy and water needs, they actually can generate heat for adjacent structures.
If the Netherlands can produce this much value on so little land, what if that country’s methods were applied to other places? Greenhouse growing would allow us to reduce the transportation costs for food by producing crops closer to urban centers where they are needed. And we don’t have to think only about the usual horizontal greenhouse. With a vertical greenhouse where planters are stacked, the rate of production per square foot of land can be as high as six times that of open farming in soil. Crops could be grown on, under, and in buildings to serve local markets.
Human beings naturally upcycle by migrating toward cities to live closer together in compact units. Urban density, by its nature, can deftly enable effective and efficient resource use while encouraging creative and diverse cultures of all kinds. Yet so much of the space in cities is underused. Certainly, we are good at packing as many people as possible into vertical space, but there is a territory in the city almost as large as the city itself that goes unemployed in the project of abundance: the rooftops. Cities and buildings, especially well-planned ones, can be reconceived as gardens. One can imagine a city from the air looking like a large garden divided into a multitude of plots.
Already, cities all over the world are being improved by green roofs. In 2001, Chicago mayor Richard M. Daley hired Bill’s design firm to conceive a green roof on City Hall. This ultimately saved the building $5,000 per year in energy costs. More important, it inspired other green roofs. Chicago’s building code is being altered to promote them. Walmart installed its first green roof in Chicago in 2008, and its commitment to green roofs elsewhere is growing.
A former naval yard building in Brooklyn is now the site for a large urban rooftop farm—100,000 square feet of greenhouse. It is estimated that it will be able to produce one million tons a year of lettuces, tomatoes, and herbs, all hydroponically (in water),2 and will sell the produce year-round to local supermarkets and high-end eateries. Bill’s architecture firm is now designing schools, offices, and factories, which are covered with solar collectors and greenhouses, accruing energy and producing organic food, clean water, and jobs.
Think about what could happen if we began utilizing all available space this way. During World War II, victory gardens, home plots planted with vegetables to help reduce the strain on domestic food supply and on transportation of goods, increased vegetable production in the United States an estimated nine to ten million tons, nearly equaling commercial vegetable production at the time. Those were dispersed gardens, using available green space or creating green space where none previously existed.