Back to the Eco-Future!

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.

Badgir in Dolatabad Gardens, Yazd, Iran, 2005. Photo by Fabien Dany

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 semiarid 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.

Diagram of a building cooled by a qanat and wind tower. Illustration by Samuel Bailey

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?

Art Molella is the Jerome and Dorothy Lemelson Director of the National Museum of American History’s Lemelson Center for the Study of Invention and Innovation.

Comments

[Rechtsanwalt Koeln]

In the northern African cities people go back to cool their houses by wind towers, because they are more efficient and cheaper than air-conditioning systems.

[Phoenix]

Thank you for this post. I am extremely interested in eco-friendly options for both heating and cooling. One question does come to mind though in these examples. Though I find both of them as viable options, I think that one of the biggest problems with either of these solutions is the complaints of surrounding neighbors who will complain about wind tunnels and wind farms as eyesores. Living here in Phoenix Arizona, the outcries of don't build that near me has already been heard. This despite the fact we all recognize alternative sources of energy are desperately needed.

Thanks again,
Jo Chris

[Johnny B]

My family and I live in a southern climate (NC/SC border) and I would love to see somebody integrate an underground passive cooling system with a superinsulated building such as straw bale. There would need to be a formula to correlate the necessary underground cubic feet of air that does the cooling with the cubic feet of air above ground that needs to be cooled. Alot of my business at has gone from residential to commercial/ industrial/ educational which tells me that central heating and cooling may be less important that it once was.