Student's have to design in factors such as is there enough solar thermal hot water for the big and small dishwashers in the kitchen and the clothes washer in a cabinet next to the small bathroom? Was the temperature in the house just right? What about the humidity? Exactly how much power would the appliances, along with the lights—mostly LEDs—draw from the photovoltaic cells that covered the roof and south-facing wall?
"We build [ICON] specifically for the Minnesota climate," said Shona Mosites, a senior studying interior design at the University of Minnesota.
Like all of the houses in the competition, the Minnesota house is compact—about the size of a large house trailer. It is extremely energy efficient, producing more electricity during the day than it uses and feeding the excess into the regional power grid. At night, when the sun is down, the house draws from the grid, but less than it feeds into the system during the day.
And like all of the other houses, the ICON house makes extensive use of green materials.
"The sliding panels are made of recycled material, and the maple flooring is two-thirds reclaimed wood," Mosites said.
A difficult road trip
At the other end of the Mall, the team from the
University of
Wisconsin-Milwaukee was struggling. The team was in last
place, and were struggling to get the house's sliding doors to
move smoothly on their tracks. Their house, valued at $485,000,
had tabletops made out of pressed paper and cashew shells and
the ability to warm up just from the heat of the people inside.
But its last-place standing reflected a 3-inch problem in the
design.
"The west end of the house was 3 inches too tall to go through
Indiana [on the transport trailer]," said Eric Davis, the
project's chief engineer. "So we had to go down through
Illinois, then cross Kentucky."
There was another height regulation problem when they got to
the edge of Washington, and it took another 20 hours to finally
get their structure to the National Mall. While the other teams
were fine tuning their home's systems, the Wisconsin team was
still wearing hard hats and putting their house together.
"We missed the metering contest, so our score is down," Davis
said.
The houses that make up the high-tech
Solar
Village are mostly from universities, shipped in multiple
pieces from around the world. Germany, Spain and two teams from
consortiums of Canadian universities also have entries in the
competition. And the event is drawing crowds, with long lines
of people waiting to tour the houses.
"About 2,000 people come through our house each day," said
Thomas Rauch, media liaison and team member of Penn State
University's
Natural Fusion
house.
The energy produced by these small structures, each limited to
800 square feet, powers all of the lighting, appliances and air
conditioning within. And on sunny days, when the houses produce
more electricity than is needed, they pump the extra energy
directly into the regional electrical grid that powers the
metro area.
The
German
team's house often gives back twice as much energy as it
uses—enough in one day to light 400 incandescent light
bulbs for one hour.
Home improvement
US
Secretary of Energy Steven Chu helped to kick-off the event
on Oct 8 (see picture left. Chu is on the right. Photo credit:
DOE) by describing his own home-improvement experiences while
working to make his home more energy efficient. "I started
doing this long before I knew about climate change. And I have
to confess the only reason I was doing that is because I'm
fundamentally cheap," he said.
Chu said that during his time at
Lawrence Berkeley National
Laboratory in California he became convinced that houses
could be made 75 or 80 percent more efficient in terms of
energy usage—before adding any solar panels. He also
announced an additional $87 million in DOE funding to further
the solar research on display in the homes.
Several of the houses are smart phone-enabled—the
interior lighting and temperature can be changed remotely with
an iPhone application. Others adjust interior conditions
automatically, using sensors that monitor time and weather data
to tint electrochemical windows and dim light levels.
