The Charge

Energy consumption in residential and commercial buildings accounts for about 37 percent of the nation’s energy budget. Buildings typically operate at less than 50 percent efficiency. The U.S. Department of Energy charge was to design, build, and operate the most effective and efficient house powered solely by the sun.

The Virginia Tech team also challenged itself to reverse perceptions of solar technology as ugly and unreliable equipment that destroys any sense of proportion and beauty in a building. Team members wanted to re-establish the ideals of solar energy by integrating architecture and technology using an architectural form that celebrates solar energy while obtaining a high level of system integration.

This project is one effort to research, realize, and test building components that will reduce the nation’s demand for energy while improving the quality of architectural space.

What’s New

•  Tuneable walls provide control of temperature, light, and color. The polycarbonate panels filled with translucent aerogel provide R-22 insulation value while delivering glowing light that animates the entire space. Increasing natural daylight is an architectural design goal because people are healthier and happier in natural light.

•  A landscape with water conservation techniques integrates the exterior and interior. Although the water system was not part of the competition, the judges commented, “The team used drainage and recycling of water to poetic, not only technological effect.”

•  The V-shaped roof is a lightweight folded-plate structure filled with foam insulation. Its form sets the solar panels at an optimum angle for energy collection while the bright, high underside enlarges the modest square footage.

•  Advanced computer tools were used to refine and to predict the performance of the design. Advanced visualization tools were used to provide a better spatial understanding of the designed solution and to facilitate system integration. A virtual environment allowed the students to explore alternative routings of pipes and electrical and communication cabling.

•  Mechanical engineering student Mike Christopher designed the user-friendly, PC tablet-based software for monitoring and controlling the systems in the house. It is connected to an outside weather station that measures temperature, humidity, light level, and wind, and controls the HVAC system, PV orientation, and batteries. "In 2002, the students kept turning the thermostat up and down to meet the 72-75 degree requirements of the competition," says Wheeler. "With this system, the house stayed at 73.5 degrees at all times, even with people coming through. Now that the house is back on campus, we are tying in the lights and electronic door locks to the computer.”

•  To keep the height of the house as low as possible on the highway, a lowboy chassis became the floor and foundation, designed to receive a detachable gooseneck and rear axles for transport. The side supports lower to become the frame for a wraparound deck. In the words of one juror, "The transportation concept was amazing." The judging panel called the "commitment early on to solve transportation as a design problem" one of the areas that set the house apart from its competitors.

What’s Next

In several instances, students suggested new and innovative approaches for the use of products to the manufacturers.

Three major manufacturers are considering a joint project to develop a product from the translucent/tuneable wall assembly that can be adjusted to any color.

A national manufacturer of cabinetry that used renewable wheat board for the first time in the products it provided for the solar house is considering wider use of sustainable materials. Wheat straw board is not only a renewable resource, but it has low volatile organic compound emissions, including a 97 percent reduction of formaldehyde emissions.

There were 75 participating industries supplying material and services to the project. The original contacts are evolving into long-term research relationships.

The college plans to become an AIA continuing education provider to deliver a unit on “Building Integrated Photovoltaics,” as well as other topics related to the highly integrated systems aspect of the project.

The house was designed to operate off the electric grid for the competition, but was also built to connect to the grid. “Grid connection makes better use of the PV (solar) array,” according to Mike Ellis, associate professor of mechanical engineering and a team adviser whose research focuses on energy use in buildings. “With grid connected operation, excess power from our house can be used in other houses without incurring the charge/discharge losses associated with storing the unused energy in batteries.” Now that the house is installed on campus, implementation of the grid interconnection can proceed.

The judges commented that execution of the plan to create a solar house “was radically different … and radically better… The jury will be interested to see what Virginia Tech does in 2007.”