"Green living is not a compromise," says Santa Clara University student Victoria Watson, a participant in the U.S. Department of Energy’s Solar Decathlon . The international competition challenges 20 university teams to design and build “net-zero” energy houses that produce all their own energy from on-site solar systems. The homes currently on display on the National Mall are not only a showcase of energy-conscious technologies and design, but also feature all the comforts of modern living. “You don't have to give up all the amenities that most people are used to [in order to] live sustainably,” points out Cory Brennan, a civil engineering student from the Missouri University of Science and Technology. “You have to live differently than what we're used to but it doesn't have to sacrifice quality of life..."

PV panels and evacuated tube systems provide electricity and hot water for Team Missouri, while whitewashed walls and blinds regulate temperature.
 PV panels and evacuated tube systems provide electricity and hot water for Team Missouri, while whitewashed walls and blinds regulate temperature.

The Houses: Technology and Design

Energy efficiency is top priority in net-zero energy homes. One effective technique is “passive design,” which maximizes a building’s ability to harness natural light, heat, and air flows through optimal building orientation and architecture. Team Missouri designed a passive ventilation system in which low-placed windows draw in cool air on one side of the house, while high, clerestory windows on the opposite side allow hot air to vent to the outside. The house also includes a whitewashed exterior wall that reflects sunlight and blinds to provide additional shade. These design elements minimize the need for an active cooling system that requires energy to operate.

After the design phase, teams use the latest off-the-shelf materials and technologies to further improve the energy efficiency of their buildings. Common features include insulation, LED lighting, low-flow faucets, ENERGY STAR appliances, and smart thermostats. Although some of these features have higher upfront costs, they are quickly coming down in price and, importantly, lead to huge savings over the long term. "These technologies are affordable,” said Rice University student Cassie Lopez. “You can make really efficient houses today with what's in stores."

The Rice University team stands in front of their net-zero house, which was designed to highlight the affordability of energy efficient technology.

Cornell University used a soy-based spray foam insulation, which has an R-value of 30 to minimize the leakage of heat in chilly New York winters. At Virginia Tech’s house, polycarbonate panels resembling window shutters were filled with an insulating aerogel, which allowed light to shine into the house while still maintaining a comfortable internal temperature. LED lighting, featured in several houses, uses even less energy than compact fluorescent light bulbs (CFLs) and will last for 20 years.

Also featured were internet applications that can control thermostats, lights, appliances, and window screens from remote locations. "You can control practically everything about the house from the iPhone," said Team California’s Victoria Watson. The use of information and communication technologies could revolutionize household energy use by giving consumers the ability to monitor information in real time and adjust systems and behavior accordingly.

Team California uses an iPhone application to control window curtains.

Of course, the Solar Decathlon would not be complete without the use of impressive solar arrays to generate energy. Teams typically used photovoltaic panels to produce electricity and evacuated tube systems with insulated tanks to supply hot water for the house 24-hours a day. These systems were designed for use in the home climate of each team -- from Louisiana and Arizona to Wisconsin and Alberta, Canada -- but are judged on their performance here in Washington, D.C. While these fully-functional houses could operate without connecting to the electric grid, they are tied into the local utility during the competition so they can sell back any excess energy generated -- a policy known as “net-metering”.

The Competition

The twofold mission of the Solar Decathlon is to demonstrate the availability of design and technology to make energy efficient buildings and inspire students to pursue clean energy careers while giving them firsthand experience in the industry. The teams compete in ten categories: architecture, market viability, engineering, lighting design, communications, comfort zone, hot water, appliances, home entertainment, and net metering. Competitors demonstrate the houses’ functionality and livability by doing the laundry, hosting dinner parties and movie nights, and operating computers for an extended time. Houses will be open for public tours on the National Mall through October 18, with the exception of October 14 when they are closed for judging.

Clean Energy Opportunities

The students working on these impressive zero-energy homes are tomorrow’s engineers, architects, and entrepreneurs. The Department of Energy states that “the Solar Decathlon encourages students to incorporate energy efficiency and solar energy into their future professional projects and personal lives,” and indeed many of the competitors are enthusiastic about working in clean energy.

Yomara Rivera, an architecture student at the Universidad de Puerto Rico wants to design green buildings and would “love to work on solar energy.” Environmental engineering student Cassie Lopez, from Rice University in Houston, wants to research solar and wind technology after school. The Solar Decathlon offered Victoria Watson the perfect creative outlet for her passions of sustainability and business. As she helped design and build a net-zero energy, solar-powered house, she became immersed in the clean energy industry and realized “as a business student, there are a lot of job opportunities.”

Students were also excited to participate in Solar Decathlon because of the hands-on experience it offers. “I was very interested in sustainability… working with the technologies that were out there, applying them…and making them feasible," stated Bobby Harvey, a landscape architecture student at Cornell University. The student participants of the Solar Decathlon are graduating from college and entering the workforce with extensive knowledge of solar and energy efficiency technologies, awareness of opportunities in the clean energy industry and an enthusiasm for sustainability. With about 2,000 students participating this year, the Solar Decathlon highlights the enormous potential—for both zero energy buildings and the creativity and ingenuity of the coming workforce to solve energy problems.

Policymaker Education

The Environmental and Energy Study Institute (EESI) will be amplifying the lessons of the Solar Decathlon for Congressional staff with two upcoming briefings. On October 14 , experts from government, industry, and academia will come to Capitol Hill to discuss the innovative building technologies and design that can be used today to improve energy efficiency, produce renewable energy, and contribute to a more sustainable and healthful living environment -- many of which were showcased in the Solar Decathlon. In addition, Rep. Bart Gordon (D-TN), House Science and Technology Committee Chairman and Cathy Zoi, the U.S. Department of Energy's Assistant Secretary for Energy Efficiency and Renewable Energy, will discuss their visions for improving the nation's building stock. On October 22 , EESI will host a briefing focusing on the potential for job creation in the clean energy sector, including public transportation. At the briefing, two new reports will be released that provide macro-level forecasts for clean energy jobs from architects and engineers to manufacturing, construction, and sales.

Click here for more pictures from the Solar Decathlon.