International Solar House Competition Helps Students See the Light

Forget the bad-boy image of those SUVs. It’s buildings that really pump energy from the planet.

After all, in the U.S., commercial and residential buildings guzzle 65-percent of all electricity, 40-percent of all raw materials and even 12-percent of drinkable water. And heating oil prospects for homes don’t look any more promising. In mid-May, weekly stocks of heating oil were off 20 percent from last year. That means supplies could remain low and home heating prices could be on the rise entering the winter-heating season.

In recognition of buildings’ energy dependency, 20 select universities from around the world – housing the globe’s best business, design and engineering programs – are engaged in a pioneering competition, each vying to innovate, design and build the best solar house possible. (The competition is called the Solar Decathlon.)

The University of Cincinnati – with its internationally recognized programs in design along with its nationally known business and engineering programs – is one of those 20 schools and has mobilized more than 200 students in its on-campus construction effort. When that house is complete in October, it will travel (along with the 19 other houses) to Washington D.C.’s National Mall where hundreds of thousands of visitors are expected to walk through it.

Among those leading UC’s effort are faculty and students from the College of Business, College of Engineering and College of Design, Architecture, Art, and Planning.

Architect Anton Harfmann, associate dean in UC’s College of Design, Architecture, Art, and Planning, explained, “Up till now, the great majority of construction has treated energy issues as an after-thought, an add on. What we’re doing here is using available technology in new ways to integrate energy solutions into a home that is 100-percent solar powered and still meets people’s needs.”

That’s precisely the aim of the international Solar Decathlon competition: To promote research and development related to alternative energy, specifically solar energy, in a home that must function as a residence and as a home-based business.

Thus, ALL the house’s needs must ultimately derive from the sun: Fully functioning appliances, mechanics like air conditioning and heating; as well as a commuter vehicle. In addition, the house must be constructed and designed using sustainable materials.

Within its 800-square-foot house, UC innovations include

• Roofing advances that include a slightly sloping, south-facing roof sheathed by a grid of 36 photovoltaic (PV) solar-collecting panels. These panels alone will produce more than enough energy to power the house, energy that can be stored for a cloudy day, sold back to the grid or used to power the electric commuter vehicle.

• Unusual utilization of evacuated tubes to create thermal energy to cool and dehumidify the house. (In other words, hot water is actually used to provide chill air or air conditioning.) As a result of the system, the UC team expects to generate four or five times as much hot water as other teams, and this places less reliance on the roof’s PV panels in case of cloudy weather.

• A unique thermo-electric heat pump that could also be used as a back up to cool and dehumidify the house.

• Read more details on the house's technical applications.

• See video of the house under construction and listen to UC engineering student Jeremy Smith explain some of the innovations in a 1-minute, 30-second clip.

Each of these innovations is important. For instance, the arrangement of the PV panels by UC’s students resolves a number of challenges currently posed by their use. Said Harfmann, “Right now, PV technology is generally embedded in existing roofs made of shingles. That means the life span of the roof and the life span of the panels are interlocked. You can’t change out the PV panels without replacing the roof. That means the rapidly improving effectiveness of PV technology does a current homeowner using PV-integrated materials no good. Second, and just as importantly, the roof commonly overheats and that actually reduces the effectiveness of the PV cells.”

The simple solution posed by UC’s Solar Decathlon team consists of a small space of separation between the conventional PV panels and the insulated, waterproof roof. This allows for air flow between roof and panels and actually means that the PV panels serve to shade the roof.

“It’s light, not heat, that causes the PV panels to operate at peak efficiency. So, this helps us make maximum use of light while reducing heat (by encouraging air flow between the roof and the PV panels),” stated Harfmann, adding that the system would allow a home owner to replace PV panels at any point as panels improve in terms of technology and efficiency. And those panels are “getting better and more efficient all the time,” he said.

The design and creation of this structure and its systems is providing a “power-full” challenge to students, but one that is worth it, according to engineering student Andy Schroder. “I want to have cheap electricity,” he said.

The actual design of the house is that of a contemporary loft-style home, including a kitchen, living area and dining area. A continuous expanse of windows extends all around the perimeter of the house just under the roofline (and thus, serves as the top portion of the wall). This uninterrupted (and wide) expanse of windows not only makes the house seem larger but also, obviously, makes for maximum use of natural light vs. electrically powered luminescence.

The house design also incorporates a shaded, outdoor deck that extends from the living area, making the space appear even larger. The modular form of the house would allow for ease of expansion if required for a growing family. Finally, the skeleton of the house is comprised of recycled steel columns and beams. 

Other aspects of the UC solar house made possible by sponsors:

• Highly energy-efficient windows and glass doors (to allow the sun in by day) wherein the incorporated blinds serve as night insulation.

• Soy-based double insulation in the Formica-paneled walls that serves as a rain screen.

The students’ work will be showcased on the National Mall in Washington D.C. from Oct. 12-20. There, each house will be judged on 10 criteria related to energy creation and conservation by means of innovative architecture, engineering, communications and hot-water creation.

Said UC architecture student Matt Mutchler, “The standards for the future could be created here.”

• See past stories on UC's solar house and watch the video from the initial "ground breaking." 

• Visit UC Admissions to apply to UC's business, engineering or architecture and design programs.