SI askedSmithGroup, one of the nation's leading architectural firms and experts inecological design, to create a self-sustaining, carbon-neutral arena (i.e., onethat would not emit carbon dioxide). SmithGroup--under architect RussellPerry--came up with a complex that would be built in the downtown of a majorU.S. city. The cost of constructing the 17.4-acre development, including its20,000-seat green arena, would be prohibitive today, but someday soon, it won'tbe.
LAND The arena islocated in an urban center for easy access to public transportation andexisting utility infrastructure. There are stores at street level and anelevated park that rises from the sidewalk to the rooftop and is supported bystruts and beams. Beneath the ramp, a bowling alley, a market or a movietheater is housed. The park also serves as the grand walkway to a hotel, builtabove the arena, with rooms that look out on the city or onto the publicgreen.
There is a subwaystation under the arena, but no on-site parking. The waterfront has beencleaned up and redeveloped, and native trees, bushes and grasses that pullcontaminants from the soil--through a process called phytoremediation--areplanted along the riverbank. A pier has been constructed to house a ferryterminal, reclaiming the river as the transportation route it once was.
ENERGY Throughsun and wind, the arena and hotel capture and store the energy they need. Inall but the southernmost latitudes of the U.S., the sides of buildings thatface south are effective receptors of solar radiation. Except for where thestores are located, the southern facade of the arena is covered in photovoltaiccells that capture energy from the sun's rays and convert it into electricity.The photovoltaic array is composed of energy-collecting crystals applied toglass. Even with the most efficient crystals, though, some of the sun's energyproduces heat--a by-product that generates hot water for the arena.
The hotel forms ahorseshoe around the rooftop park, which is open to the south. To maximize thecapturing of solar radiation, a large array of photovoltaic collectors on theinner facade of the hotel is set on a track so that it can follow the path ofthe sun throughout the day. As the array passes in front of the guests' rooms,which are shaded from direct sunlight by the array, the angles of the cellschange to leave the views from the rooms unobscured. At dusk the array facesthe setting sun. The array is then raised above the roofline, becoming an80-by-240-foot-wide screen on which events are projected through light-emittingdiodes embedded in the surface. Fans who aren't inside the arena can watch thegame from the park.
Meanwhile, thetall buildings of the city funnel wind through urban canyons of glass andsteel. The hotel above the arena captures some of that wind through horizontalslots between floors of the hotel, where, within the hotel's structure,turbines await the gusts.
AIR Theconsistently cool temperature of the ground beneath the city is used to meetone of the greatest energy demands of the arena--cooling its occupants. Withinthe foundations of the arena is a labyrinth of passages lined with masonry. Airtaken from roof level--well above the exhaust of the street--is sucked into thelabyrinth through ducts and loses its heat to the masonry; the air continues oninto the arena vent system at something close to ground temperature, about 55°.This cool air is supplied to the crowd as needed: Vents beneath the seats openwhen the seats are flipped down, releasing cool air and assuring a directrelationship between the number of fans in the stands and the air needed tocool them.
STRUCTURETriangular planes of lightweight, high-strength carbon fiber cover the outsideof the building. (A new method of producing carbon fiber--still on the drawingboard--will capture carbon from the burning of fossil fuels and sequester itwithin reusable building materials such as beams.) The arena is designed to beeasily disassembled, and is made out of materials that can be reused in anotherfacility.
DRAINAGE Rainwashes particulates from the air and off hard surfaces such as roofs, roads,sidewalks and parking lots. In many cities outdated storm sewers are choked byeven a half-inch of rain, causing raw sewage to flow into the city's adjacentriver or lake. Designed as a public gathering space, the park is carpeted ingrass with the perimeter of the seating area and much of the slope up to theroof covered in native vegetation. The plants retain and clean rain as itdrains off the roof. Whatever water flows from the site is stored in a pond atthe base of the slope, then used for the toilets within the arena.
WATER Most of thewater required by the arena and the hotel is for sewage conveyance--and potablewater is not needed for that. Toilets make use of stored rainwater, and theresulting sewage is mined for nutrients to be used in fertilizer--potassium,phosphorous and nitrogen. The limited water used in sewage conveyance iscleaned of pollutants and pathogens and returned to the groundwater.