Zero-net energy on the Washington Mall
The 2009 Solar Decathlon will take place Oct. 9-18 on the National Mall in Washington, where 20 university teams from the US, Canada, Spain and Germany each will build a self-sufficient 800-sq-ft solar home. They compete in 10 contests proving that the solar design is producing enough electricity and hot water to perform the normal functions of a home. Added to this year’s competition is a net-metering contest, which will test each home’s ability to produce its own energy.
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Twenty 800-sq-ft solar-powered homes will be transported to the Washington Mall in October, where they’ll be competing in 10 contests. Some entries, such as the one pictured here from the University of Puerto Rico, come from overseas. Photo courtesy of the University of Puerto Rico.
Each team is made up of students and advisers from multiple disciplines, with the majority focusing on architecture and engineering. Team Boston is mostly architecture students from Boston Architectural College (BAC) and Tufts University. Regardless of their fields of study, all teams divvy up the responsibilities of fundraising, marketing, lighting design, construction and more. To achieve this end, according to Jeff Stein, dean of BAC, the students have created “collaborative design studios with interior designers, landscape architects, engineers; they have brought consultants into their classrooms – like folks from the Biomimicry Institute, modular builders, HVAC [heating, ventilation and air conditioning] consultants, fundraisers, Web designers, Autodesk computer programmers … . In addition, they are working with high school students on the issues of design that they confront. This is an experience rarely afforded to students of high school age, yet Stein is certain of their capabilities.
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Members of Team Boston, which includes students from Boston Architectural College and Tufts University, are shown tacking insulation onto their solar home. Photo by Erin Baldassari.
One of the many tasks that may be unrelated to what the students are studying in school is transportation logistics. Mostly, the students are concerned with designing the most energy-efficient off-the-grid home, but they have to get it to Washington – undamaged. Logistics is, therefore, supremely important, especially for those not on the continental US. Two years ago, the University of Darmstadt in Germany traveled across the ocean to take first place. Joining the Darmstadt team from abroad this year will be contenders from Universidad Politécnica de Madrid in Spain and the University of Puerto Rico.
The role of the sun
Each team takes its own unique approach to solar design. Virginia Tech, for example, uses bifacial building-integrated photovoltaic panels on its house (dubbed “Lumenhaus”), meaning that a tilting mechanism that adjusts the arrays allows both sides of the panels to produce electricity. The house also has photovoltaic wafers within the skylight in the bathroom.
The University of Puerto Rico’s home is called “CASH,” for Caribbean Affordable Solar House, and its solar and structural design takes the hot and humid climate into consideration. The roof has 34 crystalline-silicon solar panels for electricity, evacuated-tube solar collectors for hot water, a radiant ceiling system of piped hot or cold water, an air conditioner and a dehumidifier.
Competing with light
Lighting design is one of the 10 contests, and it is judged by a jury of lighting designers and industry experts who look for things like quality of electric lighting and daylighting, ease of operation, flexibility, energy efficiency and building integration. At Iowa State, a class called “File to Fabrication,” which merges lighting and computer design, was altered somewhat to better prepare students to participate in the Decathlon, according to associate professor Mikesch Muecke, who teaches the course. Jennie Retke is one student who took the course and also participated in the solar decathlon workshop. According to Muecke, “From participating in the workshop, she knew the specs we needed to work with, the size and type of lights.” He added that, as a result, “She took a lead role in the lighting design.”
The amount of background work that goes into lighting design for any Decathlon entry is far more than meets the eye. For example, John George, a third-year master of architecture student at Iowa State, took a summer course designed to study energy consumption of the Decathlon project. The course included overall energy performance, thermal loads, diurnal shifts and mechanical system responses. During the course, participants realized that their lighting strategy greatly affected energy performance. “If our daylighting approach didn’t work as planned, we would have to turn more lights on, thus changing our projected energy consumption.” Lighting analysis is required in the rules of the Solar Decathlon, so John created an independent study course to look at the quantitative analysis of both the daylighting electric lighting design and the strategies. Using software from AGi32 of Littleton, Colo., he modeled the sunlight for different times of day and sky conditions, which provided information on how much artificial lighting would be needed, and when.
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Refract House, the entry for Team California (Santa Clara University and California College of the Arts), is shown at night illuminated by LEDs.
When asked what he had gained from the project that could be used in a future career, George was quick to point out that his role was “minimal compared to many others who have worked longer and more intensely.” He added that his role as “checker” is one that’s rarely addressed in academic settings, but it’s important in any project, and he hopes it will translate to applicable experience in the working world.
Competing for market
Lighting, solar energy and self-sufficiency are important aspects of the competition, but also critical is how the design will fare on the market, and the houses are judged on that as well. In addition to trying to win in marketability, some teams already have plans for the homes after they are hauled back to campus. The Rice University team’s home, called the “Ze-Row House,” was designed to be replicable and to fit into a neighborhood of row houses in Houston. Knowing that the home would have to be comfortable for a family in Houston’s high-heat, high-humidity climate added challenge to the team’s engineering efforts.
The students gain much from participating in the Solar Decathlon, but nothing more significant, according to BAC’s Stein, than an understanding of the consequences of our own actions. He points to the Nike slogan, “Just Do It,” which he said students have come to oppose. Instead they’ve learned that what works in terms of designing places for people to live is to “just think about it, just consider its consequences, just work out its funding, just understand how to construct it, just imagine how people will feel around it for the next few generations, [and] just imagine how to solve for the future.”
The competition takes place every two years and is sponsored by the US Department of Energy, which awards $100,000 to each team for design and construction costs. A European Solar Decathlon will take place in Madrid, Spain, in 2010.
Published: September 2009