Solar Home Competition Highlights Ingenuity,
Adaptability
by Dave Bell
Not only is residential solar design and engineering alive and well,
it just took a broad step into the twenty-first century, courtesy of the
Solar Decathlon.
The event pitted 14 college teams in a competition to see who could design,
build, and operate the most energy-efficient solar house.
"We want people to realize that solar design can look good and doesn't need to be the dated designs we all remember from the 70s," said Matthew Henry a senior at University of Colorado-Boulder, which took first place overall. Added team mate Celeste Leidich, "We wanted to show that solar design can be adapted to and incorporated into just about any house and not exclusively in competitions such as the Solar Decathlon."
Teams of students captured, converted, and stored solar energy to supply
all the power needs for their houses, using only the solar energy available
within the area of their structures. Judges scored them in ten categories,
including design and livability, heating, lighting, refrigeration, and engineering.
The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) organized the event,
with BP Solar, Home Depot, Electronic Data Systems, and the
American Institute of Architects
among the private-sector co-sponsors. The event took place on the National
Mall in Washington, D. C., beginning with construction on September 19 and
running through October 6.
Looks Like a 'Typical' House
Designing their entry to look more like a typical American home than an experimental solar showcase, the Colorado team set out from the start to prove that solar energy can be put to work in most any residential situation. They employed the BASE+ approach, which they describe as "an adaptable construction methodology for repeatable, site-specific housing that showcases renewable energy systems and environmentally sound building products."
The system consists of three components; the basic, spec, and core modules. "By combining these modules in different ways, consumer and builder can accommodate varying budgets, climates, and building sites without sacrificing visual appeal." The result is a "beautiful house that also happens to be highly efficient and solar powered," said Henry, whose team also won the award for engineering excellence.
Colorado used evacuated tube collectors to absorb the sun's light energy and convert it to heat their home's water and living spaces. "The unique feature of the evacuated tube collector is that air is removed from the spaces between the tubes, creating a vacuum. This eliminates heat loss because there is no air to transmit the heat. As a result, evacuated-tube collectors are more efficient at higher temperatures than certain other collectors."
Environmental considerations drove Colorado's decision-making every step of the way-from engineered lumber and recycled plastic sheeting to sheep wool floor insulation and a roof of recycled aluminum. To minimize waste, the team based its floor plan on the standard 4-foot width of the Structural Insulated Panels it used. To reduce environmental impacts of shipping, they chose local suppliers as much as possible.
Most Popular
With its wrap-around deck and warm, inviting look, Crowder College's entry earned the largest number of votes cast by attendees to capture the Solar Decathlon People's Choice Award. A two-year college without an architecture department, the Neosho, Missouri-based school cultivated community involvement and support-and in the process educated sponsors and suppliers about energy efficiency and solar technologies.
Because of the prevalence of sick-building syndrome and high humidity in Missouri, the Crowder team worked hard to overcome the drawbacks of tight construction. "We wanted to thermally isolate the inside of the building while still providing fresh air," said faculty advisor Art Boyt. "A positive heat recovery system allows a tightly built building to have ventilation to the outside, but to avoid the energy loss in the building. This ventilation also prevents sick building syndrome, by reducing the tendency of pollution to accumulate in the building."
The team shared its ideas with a modular home manufacturer who was looking for ways to combat sick building syndrome. "We introduced our team sponsor, KanBuild, to a positive heat recovery system and solar features," said team member Monty Pugh-Towe. "They build hundreds of buildings a year and this was a new approach that they had never tried in any of their buildings." In return, KanBuild taught Crowder students valuable lessons about portable buildings.
For a list of all the Solar Decathlon awards, plus details on each of
the entries, visit the event award page. And, to learn what will happen to
the solar homes now that the event is over, see Dave Bell's companion editorial.
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