Arthur Molella, Jerome and Dorothy Lemelson Director
|Badgir in Dolatabad Gardens, Yazd, Iran, 2005 Photo by Fabien Dany (http://www.fabiendany.com)|
So many of the sustainable environmental technologies of today hold promise but are distinctly futuristic--from nanotechnology-based photovoltaics and engineered biofuels to a full-blown vision of the hydrogen economy. Some of those may be in the offing, while others seem, if not impossible, at least so far in the future as not to be particularly helpful in getting us out of our current eco-predicament. Most also require heavy financial investment, and thus involve a significant financial gamble for society.
For example, Lawrence Livermore National Laboratory's $3.5 billion National Ignition Facility, dedicated almost a year ago, offers the promise of cheap, limitless energy through controlled nuclear fusion--the power in the H-bomb and our sun. In theory, the facility's powerful lasers, 192 of them, will fire at once on a tiny bead of hydrogen, heating it up to the temperatures inside stars, thereby converting it to helium and releasing astronomical amounts of energy. But even if laser fusion succeeds experimentally, which remains to be seen, any practical benefits are probably at least fifty years into the future.
So, why not try something radically different, like looking to the past--the far distant past? History can be a source of simple but elegant solutions to some of today's most intractable energy problems. Humans have always been adaptive animals, and adjusting to climate, food, and resources has brought forth great ingenuity since the dawn of civilization. The ancient technology of wind power, for example, has made a conspicuous comeback in the increasingly common sight of wind farms feeding the electrical grid.
|Diagram of a building cooled by a qanat and wind tower. Illustration by Samuel Bailey (http://commons.wikimedia.org/wiki/File:Qanat_wind_tower.svg)|
There is no need to stop there, however; there are many other beautiful technologies to mine from our ancient past. Just to name two, badgirs, or wind towers (also known as windcatchers) and underground water tunnels called qanats offer tantalizing possibilities as methods of passive cooling and irrigation in arid or desert regions. The city of Yazd in central Iran boasts some of the world's tallest traditional wind towers to provide natural ventilation in buildings. At the top of the towers are ports facing in several directions. By closing all the ports except the one facing away from the wind, the chimney uses the resulting pressure gradient to draw cool air from the basement and allow it to circulate around the building.
Often used in tandem with the wind tower is the qanat, a water delivery system for arid and semiarid regions, invented in ancient Iran but used throughout the Middle East, Asia, North Africa, and even the Americas. Consisting of a series of downward-sloping tunnels, qanats carry groundwater from the foothills of mountains to villages and fields below while minimizing evaporation. When wind towers are used in tandem with qanats to draw up the cooled air surrounding these underground waterways, the combination makes for a remarkably efficient air conditioner.
Many of these traditional systems are still in use today from the Middle East to China. Fortunately, a number of creative start-up companies are now experimenting with updated variants of this elegant passive-cooling system as alternatives to modern air-conditioning, a notoriously wasteful and environmentally harmful technology. When things get difficult, it is sometimes important to look back as well as forward. Who knows what else the past will bring?
From Prototype, April 2010