by Jeffrey Miles, AIA
Kiss + Cathcart Architects

Ed. Note: Jeff Miles has been using fantasy architecture as a vehicle for exploring ecological solutions for the last 15 years. Below are some sketches of his earlier ideas, culminating in an award-winning international Green Ground Zero Competition, sponsored by New York City’s Municipal Arts Society in 2004.

1. Manhattan Overcity
1992–1995
Rather than dismantle the existing city, why not build a new urban armature 700 meters overhead? Reminiscent of the plug-in Futurists and Metabolists, this megastructure would integrate new program, parks, transportation, food greenhouses, and solar/wind energy production. One characteristic of all utopian designs has been an emphasis on the city, or “concentration.” Urban areas benefit from high energy and transportation efficiencies and are also traditionally the centers of culture. Yet cities are notoriously difficult artifacts to rebuild. The work of Richard Rogers suggests one approach: His designs make a distinction between more permanent elements and those that need replacement more frequently, a quality he calls “indeterminacy.” In a similar way, building new permanent infrastructures above and below the existing urban fabric seems appropriate. Transportation, utilities, and structure could be integrated in ways not previously possible. This infrastructure could then support the more dynamic program, such as houses, schools, offices. In a sense, it is making new terrain available for development without resorting to the wasteful settlement patterns of sprawl.

2. How to Build on the Moon
1996
A footprint on the moon will last more than a million years.

What would our ethical responsibilities be for construction on new worlds?

Does the lunar wilderness deserve protection?

Imagine a lunar Environmental Impact Statement! Building underground, in select domed craters, could be a relatively benign way to build on the moon.

3. Living Bio-engineered Tower
2003
The use of biotechnology promises to be an extremely powerful tool. After all, DNA has been optimized through four billion years of evolution. Replacing machinery with organic technology offers enormous benefits: the bio-remediation of polluted sites, methods of collecting metals without open-pit mining, non-polluting energy from bacterial fuel cells. Why not use the technology to grow living, warm-blooded cities that can sprout new neighborhoods, regenerate damaged sections, recycle wastes, rotate to track the sun, grow winter fur, inflate, crawl, even swim? I know I am talking about eliminating my architectural profession. But imagine if buildings built themselves, and we could all go to the beach.

4. Green Ground Zero
(This project received an Energy Award from the Green Ground Zero Competition sponsored by New York’s Municipal Arts Society in 2004.)

The concept: To harvest renewable energy onsite and store it until needed in a pumped hydroelectric plant that is integrated architecturally within a mixed-use office and retail complex, achieving 100 percent energy self-sufficiency.

How it works: Hydroelectric power is a reliable and proven technology based on the principle of converting kinetic energy into mechanical energy at the turbine. Pumped hydroelectric storage is a variant, and rather than a river, typically involves an upper lake and a lower lake. During the day, water from the high lake drives the turbines and generators. At night, reversible turbines pump the water back up the hill. Although the energy needed to pump is greater than the energy produced, lower off-peak electric rates make pumped storage economically viable.

Urban application: Pumped hydroelectric as an urban energy storage strategy, combined with a building, is a unique application. The amount of energy in a given volume of water is related to height (hydraulic head), as well as the overall system efficiency, typically 73 percent. A height of 150 m (492 feet) was selected as a compromise among height, volume, and land area. Water would flow through the plant during the 12-hour workday. Renewable power sources would run the pumps daily, refilling the upper reservoir by the next morning.

Output: Wind production is based on AEO (annual energy output) tables, DOE wind maps, and manufacturers performance charts. (More sophisticated analysis is necessary to test the concept and establish the optimum system design points.) Balancing energy production and consumption is feasible within the WTC site, given the stated assumptions. The limiting criteria is the amount of renewable energy that can be produced on site, which results in a building of approximately one million gross square feet and a floor-area-ratio (FAR) of 2.7, less than the midtown Manhattan average of 10.

The ratio of 1 unit of hydropower generated for every 3.8 units of renewable energy harvested (ignoring reserves) implies that a more efficient system could be considered. If on-site renewable power could be used directly (through a voltage inverter), then the efficiency losses of 42 percent through the pumps and hydro plant could be eliminated.

Storage: During optimal production, average wind and solar power (5.21MW) exceed the average demand of 1.6MW by more than three times. This excess power could be used to refill the storage reservoir, which would then be utilized as a backup, and not as the primary power source. Assuming a doubling of total system energy efficiency, a higher building density of 5.4 FAR could be achieved, equivalent to London, Paris, and other major urban centers.

Other options: For high-density cities like New York to become energy self-sufficient and weaned of the fossil-fuel addiction, clearly other types of renewable sources will have to be developed, such as tidal, geothermal, and biomass. A logical alternative would be to import energy from large municipal offshore wind and PV platforms. Given the high cost of constructing elevated cisterns, perhaps a more distributed hydroelectric storage would be more appropriate, such as one larger reservoir every 10 blocks or so. Other forms of energy storage would also have to be considered (ice caverns, thermal, flywheels, compressed air) and even exotic technologies like superconduction magnetic energy storage (SMES).

Conclusion: An energy self-sufficient Ground Zero and, eventually, a zero-footprint civilization, would provide a fitting tribute for the World Trade Center.