Entry Synopses
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Windy City Urban Wind & Sun Power

Sustainability Toolbox

Up-fill Housing

A Real Green Line

Roof-top Gardening

Mobil City Farmstead

TrueCost Residential Electricity Service

TransCab

SKY Initiative

Urban Bamboo Farms

Harvesting Latent Energy in Tall Buildings

Project Name: Windy City Urban Wind & Sun Power

Leaders in Chicago and other large cities worldwide are discovering the need for renewable wind energy that might begin to complement the now accepted forms of building-integrated solar power (daylighting, photovoltaics, solar thermal, etc.) that have become part of our accepted roster of “Green Building” technologies.

Chicago needs locally produced and locally manufactured, “in-town” renewable wind energy. The possibilities for both the production of non-polluting wind energy WITH the creation of 1000s of high-paying wind energy manufacturing and installation JOBS is tremendous. However, there appear to be few practical plans for starting a Chicago urban windpower program … and for some good reasons:

The long-standing paradigms for ‘windmills’ are propeller-type wind machines that pose great problems for installations in cities because such machines:

• demand wind sites with high-speed (10 mph on average), unobstructed, steady winds year-round
• (however, cities feature gusting and highly variable winds that spinning propellers can’t easily catch)
• must rise on very tall towers above all surroundings and obstructions
• (creating fears about falling structures/machines injuring nearby residents or children at play)
• have rapidly rotating blades that can kill birds and throw large ice fragments long distances
• (raising neighbors’ anxieties regarding property damage and increasing personal liabilities)
• often produce enough noise and vibration that complaining neighbors will have them removed
• (adding to increased rumors that portray all ‘windmills’ as obnoxious “disturbers of the peace”)
• often require special zoning exemptions and special code/insurance approvals for each installation (adding to the conventional wisdom that they are not quite yet “civilized”)
• due to all or most of the above, will “lower property and resale values” and create conflicts

Our poster, Windy City Urban Wind & Sun Power proposes significant multiple remedies to the difficulties listed above. Our poster envisions appropriate urban-based and urban-installable wind turbine alternatives to the existing “propellered paradigm”. Ours is a distributed power approach similar to the accepted photovoltaic model using a refined ‘hybrid’ version of older simpler machines. These systems could be safely buildable/installable in Chicago without ANY of the concerns listed above. Our poster introduces a new paradigm for wind energy production in cities:

• that could utilize variable and gusting winds running at speeds as low as 5 mph and high as 100 mph
• that could require only low profile supports that safely enclose all turbines without noise or vibration
• that could use high-torque/low speed rotations safe for birds and safe regarding “throwing” issues
• that could run at extremely safe, low, but highly efficient, speeds totally preventing “runaways”
• that could be called “beautiful” due to the turbine’s flowing helical motions during operation
• that would be completely compatible with current building code requirements governing rooftops

ALL of the urban wind turbine applications envisioned on our Windy City Urban Wind & Sun Power poster would be designed to easily accommodate the addition of major photovoltaic systems. Safe and durable urban-based, wind/PV, hybrid, distributed renewable energy systems are the long-term technology paradigm that this poster seeks to promote as viable and cost-effective for Chicago’s Sustainable Future.

Project Name: Sustainability Toolbox

We think of sustainability as the achievement of an inter- and intra-generational equity that does not interfere with the earth’s ability to sustain life. In a healthy ecological system, matter continuously cycles in closed loops where one creatures waste is another’s food. However, an ecological system does not address other issues such as social and economic equality, which are critical values for a healthy community. Like many cities, Chicago’s problems can be seen in the linear flows of resources through the city, where we are unaware of the effects they may have before and after us. These systems make up a network of interconnected partnerships, which are vital to a community. To quote Fritjof Capra “a vibrant community is aware of the multiple relationships among its members. Nourishing the community means nourishing their relationships.”

We envision a sustainable Chicago that takes advantage of underutilized resources, such as abandoned spaces, to improve the community. By creating a toolbox of sustainable techniques, we can create a cyclical system to incorporate into these abandoned lots. These techniques can be used to improve social, economic, and environmental qualities to neighborhoods in Chicago. For example, utilizing a vacant lot for urban agriculture would encourage a neighborhood to work together to tend to the crops that will in turn be sold at local markets for a profit. This can provide an economic base for the neighborhood to make further improvements, as wells as building the community and sense of ownership over the neighborhood. In addition, by planting into abandoned ground, the crop plants are more environmental beneficial than a dirt field by cleansing and cooling the air, and reducing erosion. Our goal was to generate a toolbox of environmental practices for many systems that can provide economic stimulus and enhance communities.

Programs that are self-sustaining and can be implemented at a grass roots level can draw on many existing organizations to empower a community. There are many organizations active within the city which are making contributions towards sustainability. Part of our concept is to make these organizations more visible with a network of non-profit and governmental agencies that can work together to promote sustainable development of marginalized neighborhoods. These organizations could work collectively to acquire vacant lots and develop programs which become catalysts for positive changes toward a sustainable future. Our goal to help create a more sustainable Chicago is to work with this network to promote and develop sustainable solutions for underutilized spaces that will environmentally, economically, and socially revitalize underprivileged neighborhoods.

Instead of viewing ourselves as separate from the natural systems that surround us we should strive to restore our connections to the Earth. Not only should we attempt to achieve sustainability, which only tries to curtail the current degradation of natural systems, but we should also strive to restore and enhance them.

Project Name: Up-fill Housing

The Problem:
Rising land costs in vibrant urban areas are driving up the cost of housing and causing people to move to low density, auto-oriented areas where housing is cheaper. The disparity between income growth and housing costs is compounding the problem. These market forces are shaping inefficient and unsustainable cities and regions.

The Challenge:
How do we contain the cost of housing in vibrant neighborhoods and reshape the built environment to be more sustainable?

The Opportunity:
Most cities, including Chicago, have vast amounts of wasted space near jobs and transit that could provide housing opportunities for people who are now priced out of these areas.

The Solution:
The value of this wasted space can be captured for public and private benefits by converting it to permanently affordable housing, through the combined use of 1) air rights, 2) community land trusts, and 3) modern prefab housing.

The Mechanics:
The wasted space, a three-dimensional volume known as air rights, is donated or sold by the landowner to a community land trust. The community land trust is a legal entity used to contain land costs in order to maintain housing affordability in appreciating markets. The original owner of the air rights receives cash or tax benefits, and the community gets permanently affordable space for people who otherwise couldn’t afford to live there. The most practical way to develop housing in this space, while minimizing the disruption to the neighborhood and the underlying building, is with modern prefab architecture.

We believe our solution, which we call “Up-fill,” is part of the next generation of sustainable solutions that address complex social/environmental problems by harnessing market forces with public/private cooperation and incentives.

The Benefits:

• Lower and moderate-income people will have more housing choice in close proximity to jobs, transit, etc.
• Transportation systems will be optimized through increased access to rail, and decreased street congestion.
• Public health will improve with more biking and walking destinations in close proximity to their homes.
• More scenic/recreational open space, natural ecosystems, and productive farmland can be preserved.
• Air and water quality will improve as a result of more efficient transportation and the decreasing need for vast amounts of paved surfaces.
• Increased tax base for the city.

Project Name: A Real Green Line

reclaim rainwater | improve urban air | reduce pollution

Problem
Water defines Chicago. Basking on the shores of Lake Michigan, and enervated through its very core by active rivers and waterways, the city’s relationship with its aquatic surroundings is intimate. But decades of industrial and residential construction have left a sea of asphalt, increasing latent heat in the city and endangering the region’s major source of drinking water. Toxins, industrial byproducts, pathogens, and human and animal waste now have nowhere to go but where they should not, as exemplified by regular summer beach closings and all-too-frequent flooding – sometimes with raw sewage.

Rain can help, but with so much naturally absorptive earth sealed beneath our streets, it is possible to receive too much of a good thing. The EPA has identified polluted storm water runoff as a principal threat to water quality, responsible for impairing 13% of local rivers and streams, 21% of lakes, and 4% of the great lakes shoreline.

Solution
Despite the deleterious effects of intense development, urban density provides a number of environmentally fruitful opportunities. Public transit networks can move people and goods extremely efficiently, greatly reducing energy consumption, pollution, and unproductive time. We propose to build (literally) on Chicago’s legendary railway infrastructure in order to improve the handling of rainwater, reduce the city’s “heat island effect”, cleanse the air, and restore a touch of green to commuters’ and residents’ lives.

“Green roofing” has been deployed to great effect in recent years, most visibly atop Chicago’s City Hall, and we would like to install similar technology above the elevated railways of the Chicago Transit Authority (CTA). By intercepting rain before it reaches the city’s hard street surfaces, we expect the following benefits:

• Reduce the volume of storm water flowing into rivers and lakes by 50%
• Reduce cadmium, copper, and lead in runoff by more than 95%
• Reduce zinc in runoff by 16%
• Reduce ground temperature and the urban heat island effect – the difference in temperatures between rural and urban areas can be up to 10 degrees (F) – by shading highly conductive materials such as asphalt, steel, and aluminum
• Reduce air and water pollution through photosynthesis
• Enhance the visual presence of the CTA system

Plan
Installations would begin downtown, ultimately extending throughout the entire CTA rail network. In addition to the 500,000 daily trips we hope to make more pleasant, neighbors to the city’s 222 miles of elevated track are certain to welcome the upgrades, as wellplaced greenery can do much to tame the visually corrosive effects on residential neighborhoods of the CTA’s yellow and brown heavy industry aesthetic.

This last goal – to stimulate interest in public transit and make the city a more livable place – is intangible but far from insignificant. People make cities great because they seek interaction, exchange, and mutual support. Unfortunately, many 19th and 20th Century industrial responses to urban development have had opposite effects. Building on the venerable CTA tracks that have served the city well for decades, we hope to create a renewed platform for civic growth.

Project Name: Roof-top Gardening

Most Americans take their fully stocked supermarket shelves for granted. Few of us give significant thought as to where and how the fresh produce we require is created. Growing fruits and vegetables for an entire nation is a serious undertaking, and has far-reaching effects on our environment and economy. The complexity of food production is not communicated effectively through mass media, and is often oversimplified. Today’s crops are linked to a variety of unseen factors that have monumental influence on our nation’s food supply. These include population growth and movement, racial interaction, global climate changes, trends in diet, regional tastes and commodities trading. When considering this delicate balance within the turbulent context at present, it becomes apparent that our nation may experience a major food crisis in the near future. Many of these imminent problems may be minimized or eliminated by addressing current food production shortcomings from an industrial design perspective. Of the several solutions examined for this project, the idea of widespread urban rooftop agriculture was deemed most appealing. Expansive rooftop gardening in Chicago would have measurable positive effects on the natural environment, encourage social progress and provide an opportunity for industrial designers to develop innovative solutions that could preserve the planet and rescue mankind from poor health or starvation.

The environmental benefits of extensive participation in rooftop gardening include landfill waste reduction, transportation and energy savings, improved air quality, beautification of public space, decreased sewer strain, the establishment of urban wildlife sanctuaries and slower urban sprawl. Communities within the city would benefit socially, for the teamwork required for this effort would build friendships, increase psychological health and create synergy among immigrant populations and various age groups. Participants would enjoy a healthier lifestyle and organic vegetables with a greater variety and more nutritional value than current supermarket offerings. Industrial design plays an integral role in every stage of the construction and operation of urban rooftop gardens. Everything from the raised-bed infrastructure for the plantings to specialized tools and work areas must be designed expressly for this setting. Custom hoists or elevator platforms will be necessary to transport materials and workers from the ground to the rooftop. This flexibility will afford the utilization of mixed-use real estate. A rainwater storage and drip irrigation system would need to be designed to take full advantage of the growing space. Designing special lightweight materials for use in a layered growing medium would allow us to maximize fertility while controlling water retention and oxygen respiration. Modular planting vessels and a system of racks and shelves would maximize vertical space and allow us to strategically position crops to maximize the available sunlight or shade. A multi-bin compost system is necessary to maintain a continuous flow of fertile soil. A collapsible greenhouse area able to withstand extreme temperatures and high winds would enable year-round use. These features only hint at the possibilities that exist for utilizing a vast amount of unused space within the city, conserving natural resources and promoting sustainability while revolutionizing food production methods.

Project Name: The Mobile City Farmstead

Ken Dunn of Chicago’s Resource Center, a non-profit organization with recycling, composting, and education programs, is on a quest to transform the way we cultivate and consume our food — to cultivate it organically and to market and consume it locally, so that our food need not travel thousands of miles to reach our dinner table. You don’t have to look too far to see abundant opportunities to grow our food very close to home.

There are over 90,000 vacant lots in Chicago, representing more than 6,000 acres of underutilized land. With the simple introduction of a layer of nutrient-rich topsoil, Ken Dunn has created productive farms on several vacant lots on Chicago’s South Side, providing fresh, organic produce to local residents, farmers markets and restaurants.

But don’t mistake Dunn’s urban farm ventures as a mere hobby. Fully recognizing that to transform the marketplace into one that values locally grown, quality, organic produce, Dunn aims to make each urban farm a viable, profitable business. Each farm employs 1 to 3 persons, usually homeless or unemployed individuals whom he trains, and seeks to provide them a living wage. While local residents may stop by for a few vegetables, the farms, at present, sell most of their bounty to local upscale restaurants such as the Frontera Grill and the Ritz-Carlton, who are willing to pay a little extra for high quality, organic produce.

Our team has partnered with Ken Dunn to provide a design for a mobile storage and office facility for his newest urban farm, called City Farm, located at the corner of Division and Clybourn, next door to the Cabrini-Green housing project. Although we are using the Division and Clybourn farm as our site, the intent is that this facility can be duplicated on other sites as well.

We’re calling this facility The Mobile City Farmstead. It will provide tool and produce storage, sheltered workspace, an office, restroom, temporary housing for one employee, and a small farm stand. The Farmstead will also serve to anchor the site, focusing attention to the entry point and providing a place from which to conduct educational classes, tours, and summertime dinner gatherings.

The architectural components that make up the Farmstead will be those that are salvaged, cheap, degradable and, especially, easily transportable - such as shipping containers, chain-link fencing, canvas, and straw bales. The idea of mobility is critical since City Farm must be able to relocate quickly when the site is sold or ready for redevelopment. While the Farmstead will lend City Farm a sense of establishment (key to the success of any business venture), it will sit as lightly on the land as the agriculture itself.

Together, the agriculture and architecture will give new life to once forgotten pieces of the urban landscape, encouraging curious onlookers to become educated consumers and participants, thereby generating momentum for the drive toward a local, sustainable economy.

Project Name: The TrueCost Residential Electricity Service

Whether or not you were a conservationist, if your sink was running you’d turn it off, because it’s clearly wasting water. But how do you know when you’re wasting electricity? Today’s electricity services provide you with little tangible evidence of how much electricity you’re using, to say nothing of your inability to understand the impact this use has on your pocketbook and the environment. Our TrueCost Residential Electricity Service makes electricity use tangible so people can make conscious and wise electricity use decisions.

Working in consultation with the Center for Neighborhood Technology our team has used their Community Energy Cooperative as a platform for our design. The Community Energy Cooperative provides:

Customers with access to market rate electricity prices which are almost always lower than the state-mandated flat rate;

Emails describing prices 24 hours in advance so customers can plan electricity use accordingly;

Conservation education to Co-Op members;

Tools and products with which to conserve energy.

We consider our TrueCost Residential Energy Service to be an extension of this program.

We have also based our design on findings from the field of environmental psychology regarding conservation behavior. It has been widely documented that people with attitudes strongly supportive of energy conservation are no more likely to conserve energy then those without such attitudes (Archer et al. 1987). Workshops and home audits disseminate information but rarely result in long-term behavioral change (McKenzie-Mohr, 1999 and Jordan, 1986). The field of environmental psychology suggests that verbal or written commitments to change and in-context conservation prompts have a dramatic impact on actual behavior (McKenzie-Mohr, 1999). Our design incorporates these principles to promote conservation.

The goal of our service is to help Chicago residents commit to a path of increased conservation through participation in a well designed feedback loop which ties electricity use to its true financial and environmental costs. The three major components of our design are as follows:

1. Assessors and Committed Conservation
Our assessors will not only audit each house, provide conservation products, and install our in-context meters; they will also get written commitments from customers to achieve up to three levels of conservation (essentially beginning, intermediate, and advanced conservation levels).

2. Meters that Mean Something
Our meter will be the opposite of the illegible, outdoor electricity meter, providing real time electricity pricing in the home (via a daily internet download). It uses a simple interface that constantly compares usage to the goals established with the assessor. Using electric wiring as a communication network, several other small meters will be distributed throughout the house providing in-context reminders of conservation goals.

3. Monthly Bills and Continual Feedback
Our monthly bill completes the feedback loop by tying energy use, conservation goals, and financial and environmental costs together. It will describe the benefits of participation in terms of pollution and money saved and will encourage “graduation” to the next level of conservation. It will not only compare each month’s usage to last year and the established goals, but will also compare usage to the average electricity usage on the customer’s block ensuring that the information is compelling and relevant.
Everyone a Conservationist
Our service makes energy use tangible. Like a running sink, it lets you know when you are unnecessarily wasting electricity. More importantly it helps you make wiser, daily electricity-use decisions. The TrueCost Residential Electricity Service makes everyone a conservationist.

Project Name: TransCab

TransCab is an urban taxi service utilizing hybrid electric vehicle (HEV) technology. Taxis, within the urban environment, present an ideal opportunity to implement this technology. Individual taxis run twenty-four hours a day and often have very poor gas mileage. This makes taxis significant contributors to Chicago’s poor air quality. Taxis are also extremely visible, which makes them the perfect advertisement for a technology that has such tremendous potential to reduce pollution. Using technological advances such as regenerative braking and fully recyclable nickel-metal batteries, TransCab vehicles produce significantly less pollution than even the most advanced conventional engines. Relying heavily on battery power, TransCab vehicles greatly reduce harmful smog-forming emissions proven to cause lung damage, heart conditions and cancer. To further reduce pollution, TransCab has set up select points around the city, including the two Chicago area airports, where riders may carpool to north, south and west-side neighborhoods. Although at first it may seem like a simple concept with a simple name, TransCab represents a major step forward in urban planning and everyday city life.

Embracing the simplicity of its identity, TransCab aims to bring environmentalism into mainstream awareness. TransCab gives those who might normally be unconcerned with environmental responsibility an easy, accessible and clean way to move around the city. The cleaner running HEV technology used in TransCab vehicles allows Chicagoans to seamlessly integrate their own everyday needs and the ever increasing need to address environmental concerns. In an effort to promote this integration we sought to give TransCab the look and feel of the everyperson. TransCab transforms HEV technology from a seemingly expensive and inconvenient concept into an idea that is available and relevant to everyone.

To maintain this relevancy, TransCab takes advantage of potential city tax incentives which offset the initial expense of HEV technology. These incentives, when coupled with the long-term profitability of reduced fuel costs, considerably reduce operating costs (and rates). However, low rates are not TransCab’s only competitive advantage. TransCab is an employee owned and operated company whose business strategy revolves around social, environmental and economically sustainable practices. Our drivers enjoy what they do and take pride in their job, and because our drivers have a stake in the company, our customer service far exceeds what cab users have come to expect.

TransCab is not just a new way to move through the city, TransCab is about moving into the future. It is about changing the perception of what is possible for Chicago and her community. TransCab functions not only as a more environmentally benign means of transportation, but as a vehicle that takes you to what is possible.

Project Name: SKY Initiative (Sustainable Knowledge for Youth)

"In the end we will conserve only what we love; we will
love only what we understand; and we will understand only
what we are taught.”
—Senegalese ecologist Baba Dioum

The Concept
This initiative for the Chicago Sustainability Design Challenge results from the synthesis of two ideas:

1. The public and private school system should be the genesis for society to understand and embrace sustainable ideas
2. The expertise found in mentoring programs can fuel ideas for the demonstration of innovative, sustainable solutions.

Project Approach
This project links three key stakeholders: an existing non-profit Chicago school mentoring program, several key environmental organizations, and Chicago school students. The Initiative will be achieved by integrating the following broad elements:

• Create awareness of environmental issues through mentoring programs
• Explore possibilities that address sustainability
• Grow ideas; implement visions of the concepts

The existing program currently includes mentoring at over 40 Chicago schools primarily with grades 6 through 8. This is the ideal demographic to discover the concepts of sustainability.

Stakeholder interactions will include on-site visits and a web site, where students can have frequent electronic discussions with mentors, teachers and other students. One of the environmental organizations has volunteered to create a web-based system to foster seamless collaboration, where all participants can have free-flowing electronic discussions.

How it Works
For example, a mentor may give a talk about energy use and how this global concern affects the students locally. In turn, the students may learn more intimately the challenges facing our energy needs. The students will be encouraged to ask “what if” questions of the mentor that will begin to foster the seeds of problem solving in this area.

Teams of students and mentors would then be formed to explore the possibilities of solving the problem or exploring the new idea. For example, what would be the energy impact if an alternative source of lighting were used in the school? Would there be additional benefits? Students would be asked to be as specific as possible as to the economic, social, and sustainable benefits of the new idea and to put it in writing as a blueprint for change.

The blueprint would be posted on a web-based forum and would be reviewed by mentors and school officials to determine the feasibility of implementing the idea. Simple plans could be implemented as a program change or behavioral change among students and faculty.

Financial feasibility would also be part of the blueprint and will address such questions as “how much will it cost?” or “how long will it take to pay for implementing this?” The mentor firms would help identify sources of funding.

The net result will be that students will show the way to bring about sustainable thinking to schools, neighborhoods and their City.

Criteria for Success
Mentors from participating companies have the knowledge to facilitate new ideas generated by students to address sustainable issues that face us today and tomorrow. The frequency of the web site and number of “ideas” generated will be metrics for measuring the success of the program.

Through knowledge, students will gain understanding and a love for the natural resources that are Chicago’s. The impact of problem solving will yield results for generations.

Project Name: Urban Bamboo Farms

The inhabitants of today’s cities consume an ever increasing quantity of resources from the global economy, and pollute beyond the earth’s absorption capacity. All of our decisions have an effect. Solutions must not only reduce the impacts of our lifestyle, but improve the potential sustainability of our economy, our environment, and our society. To improve sustainability, we must be aware of the connections between local decisions and global consequences. Our proposal attempts to address sustainability on a global scale through local decisions.

Bamboo is a renewable resource that has been used for thousands of years by cultures throughout the world. We believe bamboo grown on urban brownfields can address the need for global sustainability as well as the needs of low-income communities, and local consumer demand.

There are hundreds of species of bamboo that are native to various landscapes, from very warm and moist climates to much colder ones. The bamboo varieties Moso and Madake will thrive in Chicago’s climate . We believe these can initially be imported or purchased from small scale domestic growers.

Working with the EPA and the City of Chicago, Brownfield sites cultivated with Moso, Madake, and other bamboo species offer an alternative remediation strategy to the dig and hall practice currently in place. Removing contaminated soil and dumping it in a designated landfill does not address the problem of brownfield remediation. Not only will the bamboo absorb pollutants in the soil, but it will also serve as an affordable and renewable raw material with indirect environmental and social benefits.

On the community level, bamboo provides aesthetic improvements on vacant land, reduces runoff rates, and possibly improves energy efficiency. Cities continue to generate demand for housing, food and raw materials, as well as clean air and water. Unfortunately, these demands are not met in many low income communities. Therefore, we recommend that brownfield sites close to low-income communities take priority in this remediation process. Urban bamboo farms will provide local employment opportunities in the field and in the refinement process. Bamboo farms will also grant environmental justice to low income communities.

At the regional level, bamboo serves many ecological purposes. Bamboo is an excellent tool for watershed management. Not only can it reduce runoff rates and pollutants in the water table, but it is a better carbon sink than most trees. This helps to improve air and water quality . As the supply increases, the city will have an increasingly affordable and renewable raw material that can be used for building construction, among many other things. Remediated brownfield sites provide land for possible development, reducing sprawling growth patterns.
The local production of bamboo will also have positive consequences on a global scale. Bamboo can handle more pressure than steel and reaches maturity in three to five years, whereas most hardwoods require 30-50 years . This makes it an excellent building material. Growing bamboo locally will minimize the need for trees and reduce the emissions generated from shipping overseas imports.

Project Name: Harvesting Latent Energy in Tall Buildings

Chicago’s Central Business District contains 112 million square feet of office space on a relatively small geographic footprint. This translates to many tall buildings, the heights of which require that people and materials are routinely raised to significant elevations. Upon descent, the invested potential energy of these materials is wasted as heat. We propose to recover this potential energy, particularly from the descent of wastewater.

The first opportunity considered was elevator systems, which are raised with a considerable investment of energy, and then utilize a braking system to check their descent and wasting the kinetic energy as heat. A regenerative braking system could convert a significant portion of this energy into electricity. While we think this is an avenue that warrants further research, the cost of retrofitting existing elevators and performing requisite safety tests may be prohibitive. Indeed, the most economical approach to elevators would be employment of a single motor/generator system for initial installation.

The second option researched was water circulation. By utilizing the flow to rotate a turbine, electricity can be generated. Wastewater is discharged into the sewer system at a few locations in a taller building, making installation of a turbine economically feasible. The solids, however, present an additional engineering problem.

A more tractable application is the HVAC closed loop evaporative cooling system. Air moves across the cooling water enabling the heat exchange. Due to evaporation there is a need to exchange the water to prevent calcification, providing a natural break in the plumbing where a Pelton turbine can be inserted to generate electric. This approach has the following advantages:

• Minimal installation
• Minimal space requirements: less than 1 m3
• May be installed into any existing building with a cooling tower
• No risk to tenants
• Pelton turbines are available off-the-shelf for around $700
• Power is generated at peak usage times: hot summer days

We chose the EPA’s green building on Jackson as our typical building. It is 28 stories high and is in operation 12 hours per day. We obtained the cumulative water volume in the system, the pipe sizes and calculated a flow rate (Q). Power is given by P (watts) = 9.8 * Q (l/sec) * Head (m) * Efficiency (50%). Installation of microhydro generators in the cooling water blowdown system of this building would produce approximately 230 W of electricity. Over the period of a year, however, it would generate 750 kWh, for savings between $50-100 a year. These numbers can become more favorable by simply changing any of the inputs: a higher drop, a greater water volume, or a higher efficiency. Thus, microhydro electricity generation in tall buildings from cooling system blowdown affords a modest return, but serves to demonstrate the concept. A more economical follow-up project would focus more broadly on any wastewater descending in tall buildings. In this case, the additional flow rate and economy of scale should compensate for the additional engineering challenges.