The U.S. Department of Energy’s Solar Decathlon is a high-profile international competition in which 20 collegiate teams design, build and showcase solar-powered houses. Since the inaugural competition in 2002, each event has expanded the knowledge of solar living worldwide, through innovative and breathtaking designs. Our team from Purdue University in West Lafayette, Ind., was committed to do this and more in the 2011 competition — we built a real-life solution that broke common solar living notions through an affordable and practical house, the INhome.
Short for “Indiana Home,” the INhome started out as an idea of five students and one faculty member in the summer of 2009. We visited the Solar Decathlon 2009 to get first-hand insight on what the competition entailed. Of the many ideas we brought back, the most important was building an affordable, highly competitive solar-powered house. We were motivated to create a real-world design that helped solve a real-world problem.
The INhome was designed to be a fully functional yet practical net-zero-energy home for a typical Midwestern homeowner. It featured commercially available, high-efficiency systems and sustainable design, without sacrificing modern comforts and amenities. An open floor plan created a large, comfortable and inviting space. Our house had to be easily transportable, so we designed it to use six core units made of structural insulated panels (SIPS). With only seven days to reassemble the house at the competition, our team performed a practice tear down and rebuild a few weeks before the event!
We finished second overall in the Solar Decathlon 2011. With particularly cloudy weather throughout the competition week, our house was one of the best performing entries. The INhome was one of only seven houses to reach net-zero, which we accomplished with help from a 8.6-kilowatt SunPower photovoltaic array. INhome also featured a mechanical system that performed exceptionally well in the humid Washington, D.C., weather. Another notable accomplishment is that INhome was valued at $257,000, earning a third-place finish in the Affordability Contest, a new component of the 2011 competition. Many of the INhome’s 18,000 visitors left saying, “Now this is a home I could live in!”
Few former Solar Decathlon houses have become full-time residences. In fact, of the 100 houses that exist, only five are occupied on a daily basis. Of those, only two have been placed in communities, where the bulk of Americans live. Keeping true to its goal of being a “real home for a real family,” the INhome has been placed in a community in Lafayette, Ind. — as part of a broader neighborhood revitalization effort. The home will be monitored to support ongoing research into the long-term performance of cost-effective net-zero-energy homes.
Over the course of two years a core team of 15 students, along with more than 200 students from six different colleges, worked on INhome. Purdue developed several classes to help the students collaborate and receive course credit, and six graduate research projects have been based on the house.
For most students, the project ended at the conclusion of the Solar Decathlon 2011. However, as our lives move on, the INhome will continue to do what we designed it to do — impact residential construction and influence more homeowners to consider solar living not only locally throughout the Midwest, but worldwide. The INhome is evidence that solar housing is practical, affordable and a reality today.
Talk with INhome team managers Sarah Miller and Matthew Hebdon, and Randy Rapp, associate professor of building construction management technology at Purdue, at the World Renewable Energy Forum, May 13-17 in Denver. They will be presenting a poster: “Determining Typical Buyer Sensitivity for Solar Installation Cost—Energy Savings Benefit.” Access wref2012.org for a schedule and to register.