Preparing for the 2011 Solar Decathlon

The Solar Decathlon is a high-profile international competition sponsored by the U.S. Department of Energy where university students design, build, and demonstrate solar powered homes that are fully operational and cost effective. It is held every other year and has drawn in excess of 300,000 spectators plus significant national and international media coverage. This project is large and complex, even for a research university where students routinely participate in a variety of national and international competitions. Students have two years to make the home a reality, but the project encompasses far more than design and construction. Tasks like fundraising, public relations, marketing, and logistics are also significant efforts. In fact, the teamwork aspect of the Solar Decathlon might be one of the lasting legacies of the project. Students and faculty from nearly a dozen different departments that wouldn’t normally have close collaborations are working together to get this project accomplished. This paper will discuss one team’s preparations for the 2011 competition and provide insight about what outcomes other universities can expect by participating in this event. What is the Solar Decathlon? The Solar Decathlon is a high-profile international competition sponsored by the U.S. Department of Energy (DOE) where teams of university students design, build, and demonstrate solar powered homes. 1 Although the homes are limited to 1,000 ft 2 ; they are fully operational in every respect. Since its inception in 2002, this event has been held every other year on the National Mall in Washington, DC where it draws in excess of 300,000 spectators plus significant national and international media coverage. Figure 1 is from the most recent 2009 competition. The National Capital is in the background and helps convey the grand scale of the event. Figure 1. The Solar Decathlon takes place on the National Mall in Washington, D.C. P ge 22175.2 The Solar Decathlon is part of DOE’s strategy for gradually moving the market for residential buildings closer to net zero energy. In other words, the goal is that homes in the not too distant future will use renewable energy, typically solar and wind, to generate as much onsite energy as they consume on an annual basis. The final year of the Solar Decathlon is planned for 2020; by that time it is hoped that the technologies for net zero energy homes will have become commercially viable and cost effective. The name “Solar Decathlon” is used because the winning home is the one with the highest cumulative score in ten different events. Table 1 shows that roughly half of the contests are measured and the other half are determined by a jury. All contests have the same point basis. The “home entertainment” contest is a student favorite. It evaluates a dinner party thrown in the solar decathlon house for one of the other teams in the competition. Table 1. The Solar Decathlon has 10 contests. Measured Contests Juried Contests Comfort Zone Architecture Hot Water Market Appeal Appliances Engineering Energy Balance Communications Affordability Home Entertainment The measured contests listed in Table 1 are mostly self-explanatory. The “comfort zone” contest measures the ability of the home and its HVAC system to maintain specified levels of temperature and humidity. The “energy balance” contest compares the electrical loads for the home to the power generated by the home’s photovoltaic array. The goal is for the home to be net positive in terms of its interaction with the grid. In a change from past Solar Decathlons, the 2011 competition will not award bonus points for power generation past the net zero point. The juried contests in Table 1 include obvious things like architecture, market appeal, and engineering. The “communications” contest evaluates how well the team conveys information about the home to visitors who tour the home during the competition, either by signs or by tours provided by team members. The “affordability” contest is particularly compelling for 2011. To emphasize the cost effectiveness of net zero energy construction, the DOE has imposed a cost ceiling of $250,000 on all homes and has hired an estimating firm to conduct independent appraisals. Homes that are over budget will be penalized. $250,000 may seem like a lot of money for a 1000 ft 2 home, but the retail value of the photovoltaic array is at least 25% of the final cost. It will be interesting to see how many teams actually meet the cost cap.