Biowalls, iPads, sheep vie in Solar Decathlon
WASHINGTON -- The California house looks like a pillow but has an iPad app to control window shades and 3-D cameras to adjust lighting based on movement inside.
The University of Maryland's "WaterShed" has a waterfall designed to control humidity, and Purdue University's "InHome" has a self-watering biowall with vertically arranged plants.
For New Zealand's vacation-style house, or "Kiwi bach," students sheared sheep and "stuffed (wool) in the walls" for insulation, says team member Nick Officer.
Welcome to the 2011 Solar Decathlon, a showcase of state-of-the-art green building by 19 of the world's most innovative academic teams. The biannual competition, sponsored by the U.S. Department of Energy, opens to the public today for two weeks in Washington's West Potomac Park, near the National Mall.
The teams — 15 from the USA and one each from Canada, China, Belgium and New Zealand — are vying to see who built the most stylish, efficient and affordable solar-powered house.
Their prototypes, which the students designed and built during a two-year period, then reassembled within a week at the decathlon site, reflect rapid changes in technology.
Unlike the first decathlon in 2002 or even the last one in 2009, almost all of the houses now have smart meters or automation devices that track energy use in real time, plus triple-pane windows and LED (light emitting diode) fixtures.
"The shift has been pretty dramatic," says Fred Maxik, chief technology officer of Lighting Science Group, an LED manufacturer that donated lights to six of the homes. "Today, (LEDs) are ubiquitous."
The solar devices themselves have improved. They include a canopy of 42 bi-facial solar panels collecting sunlight from above and reflected light from below for Appalachian State University's house, and a rounded rooftop system for the University of Calgary entry.
Perhaps the biggest change this year is cost. DOE is emphasizing affordability and will subtract points for houses that cost more than $250,000. Each team accepted into the competition is given $100,000 in grants as start-up funding. DOE estimates each house's final price tag, based on a list of parts.
"It brings parity to the contest," says Richard King, decathlon director. "We don't want people buying it." In 2009, Team Germany won with an ultra-modern, cube-like house that King says cost about $800,000.
He says the spending limit has made the competition more challenging. "It's been amazing what's been done," he says. "We're delighted."
Most entries this year cost $250,000 to $300,000, which might seem pricey because all have 1,000 square feet or less, and two bedrooms at most. But all the houses produce at least as much energy as they use and have other distinctive features.
Several have super-thick walls and roofs, based on the Passive House model in which superior insulation and air sealing slash energy needs up to 90%. An example is "Empowerhouse" from Parsons The New School for Design and the Stevens Institute for Technology.
The houses are judged on 10 criteria, and special awards are given in five of them: affordability, architecture, engineering, communications and market appeal. The overall winner will be announced Oct. 1.
