Learning to Live on Alternative Energy
Learning Objectives - After this course, you should be able to:
- Describe building projects that use alternative energy sources.
- Explain how cogeneration works and its benefits.
- Discuss how wind turbines can be used in urban environments.
An alternative can only exist when we have a choice. Architects have that choice now when it comes to energy. We can incorporate alternative energy sources, even electricity generation, into our projects, or we can just hook them up to the grid and let someone else worry about it. There are advantages and disadvantages to both, of course, but soon we may reach the point where we have no choice, and then we will need to find ways to successfully integrate alternative energy strategies into our projects. The three case studies that follow-in Chicago, Washington, D.C., and New York-provide some answers.
Near North Apartments, Chicago, 2007
Near North Apartments, a year-old, 96-unit, single-room occupancy in Chicago, was designed by Murphy/Jahn and developed by the nonprofit organization Mercy Housing Lakefront as a model of sustainability. While most of the building's green technologies, such as a graywater recycling system that flushes toilets and a rainwater cistern for landscape irrigation, are hidden behind the scenes, its most visible ecofriendly feature is also its most experimental: A horizontal-axis wind-turbine system created by Chicagoan Bil Becker forms a lacy crown atop architect Helmut Jahn's streamlined design.
Becker is a professor of industrial design at the University of Illinois and the founder of Aerotecture. Although he first applied for a patent for the Near North installation's technology in 2000, his research dates to the 1970s. Becker, an acolyte of Buckminster Fuller, won in 1979 one of the Carter administration's last research grants devoted to alternative energy.
"Windmills only work out on the farm," Becker says of his first foray into an urban turbine almost three decades ago. But although capturing urban wind offers the opportunity of producing clean energy within cities, the location of the turbines also entails special limitations. Specifically, if a turbine were to display "runaway" behavior, throw ice, or transfer high vibration or sound loads to interior occupants, its chances of gaining a building permit would be slim.
Four years into his research, Becker realized that traditional propellers were not commensurate with urban needs, and in the following three years, he experimented with helical blades: In wind-tunnel environments, cardboard models of this Savonius rotor did not require much wind speed to start turning. Moreover, "They wouldn't overspin. They would get in their own way rather than fly faster and faster, because it has a limited amount of lift-about 10 percent lift to 90 percent drag, he says."
Becker proceeded to combine the Savonius rotor with a Darrieus rotor, which looks like an oversize whisk and "can bring you to a high rate of speed and power." Thanks to their differing starting torques and speeds, the hybrid rotor can generate power in a variety of wind environments. In fact, the Savonius and Darrieus rotors play off one another's strengths. Comparing the Darrieus to "second gear," Becker explains, "If I didn't have the Savonius blades, the Darrieus might not start. It's like the starter motor in your car. We wouldn't be driving internal combustion engines if we didn't have an electric ignition."