green@work : Magazine : Back Issues : Jan/Feb 2004 : Innovations

INNOVATION

Blending Solar and Architecture, Chicago-style
Two pavilions promote solar technology in the Windy City's "front yard".

By Gabriela Martin

One of the nation’s largest electric utilities is supporting solar energy in the next millennium. Millennium Park, that is. Chicago, IL, electric utility Commonwealth Edison (ComEd) and parent company Exelon Corp. are making a $3 million joint donation for solar technology in Chicago’s Millennium Park, which is expected to be one of the world’s most stunning public spaces. This effort aims to promote and showcase renewable energy and helps bring Chicago closer to its goal of becoming the country’s “green capital.”

Currently in the design phase, the project will create two pavilions positioned on either side of the park’s indoor Chicago Music and Dance Theater. Construction began in fall 2003 and should be completed in June 2004. Each 6,000-square-foot pavilion will also utilize a 37.5-kilowatt (KW) Building Integrated Photovoltaic system (BIPV). According to Edward Uhlir, Millennium Park project design director, the decision to use BIPV was not only an architectural plus, but also a practical solution over using a traditional solar roof installation.

“Since this is a park, the opportunity to have lots of roof surfaces really doesn’t exist. Even the Music and Dance Theater is largely built underground, so the idea of using the PV in the wall system made a lot of sense,” said Uhlir. “And we thought if we could find the right system, it would be an attractive façade for the building as well.”

Hammond Beeby Rupert Ainge Architects (HBRA) is designing the pavilions as two minimalist-style, black-glazed cubes. These glass façades will integrate photovoltaic (PV) modules on the outside surfaces.

After extensive research and consultation, HBRA decided to use customized mono-crystalline PV modules, modified to function within a curtain wall system. A curtain wall is a non-load bearing exterior wall that behaves as a screen. It can be made from a number of materials such as brick, stone or, in this case, PV cells.

“All of the black on the façades you see is PV. We think it is perhaps the first of its kind in Chicago, perhaps even in Illinois,” said HBRA architect Cyrus Subawalla. “The Exelon Pavilions are being designed to be demure in stature and to ‘urbanistically’ blend in with the formal symmetries of the surrounding park landscape.”

Subawalla also noted that the PV modules aim to meet the requirements and standards of the National Electrical Code as well as the Chicago Building Code. “We consider this project a unique example that addresses important architectural issues of sustainability, context and simplicity,” he said.

The energy generated will essentially power both pavilions, working toward self-sufficiency and cost efficiency. In addition, the pavilions’ double wall system will reduce energy consumption costs. Through the wall’s ventilated cavity, each building’s heat loss or gain will be minimized.

When completed, both pavilions will serve multiple roles of being park public information centers and display zones for Exelon Corp. and the Chicago Park District. Specifically, the West Pavilion will have Exelon exhibit space, park offices and client specific amenities. The East Pavilion will have additional exhibit spaces, including information about the value of PV and how it generates power for the pavilions.

The pavilions are a portion of an overall city effort to build and enhance Millennium Park. Funded by city and private funds, the Millennium Park project is a joint venture intended to enhance park, recreation, cultural and transportation facilities along Chicago’s Lakefront.

“It’s a public-private partnership initiated by the Mayor of Chicago, starting in 1997. The individual, privately-funded projects within Millennium Park are what we call park enhancements, of which the Exelon Pavilions are one of those,” said Uhlir.

The park, two-thirds of which will be entirely new park land, covers what was formally a surface parking lot and existing railroad tracks and terminal, which remained. This had long been considered unsightly space that occupied a major portion of the city’s “front yard.”

Although the Exelon Pavilions will not be completed until mid-2004, parts of Millennium Park are already open to the public. These include the popular McCormick Tribune Plaza and Ice Rink, the Millennium underground parking garage, and a landscaped parkland of over 400 trees.

Other park enhancements currently under development include: the indoor Chicago Music and Dance Theater designed by HBRA; an outdoor Music Pavilion designed by renowned architect Frank Gehry; a 100-ton reflective sculpture by artist Anish Kapoor; and a 2.5-acre garden whose design was part of an international competition won by Gustafson Guthrie Nichol.

When completed, Millennium Park is expected to be Chicago’s newest world-class destination for families, tourists and convention-goers. According to the Public Building Commission of Chicago, Millennium Park will guarantee the city new jobs and revenues for decades to come. Conservative estimates say it could generate $100 million to $150 million of new tourist revenues each year.