Competition History 
The Spanish government’s first Solar Decathlon Europe (SD Europe) took place last month in Madrid, Spain. SD Europe is a spinoff of the version hosted in Washington D.C. and organized by the United States Department of Energy, with two biannual competitions held on alternating years. The Queen’s Solar Design Team (QSDT) has now visited both of the sister Decathlons; these fact-finding missions have supplemented ongoing research at Queen’s as well as provided us with an insight into the nuances of each competition.

Each Solar Decathlon features roughly twenty university teams from around the world. Team members are guaranteed an unparalleled learning experience that involves working in a multidisciplinary setting, connecting with leading businesses in the clean-energy sector, and applying classroom theories to tangible projects. These competitions are meant to educate the public about the many cost-saving technologies and techniques that can be applied to their own homes.

Every house in the competition serves as a demonstration that energy-efficiency and sustainability are not mutually exclusive from affordable and comfortable living. A second goal is to generate awareness about solar power and renewable energy, technologies that can be used to create the next generation of buildings—net positive energy structures, which can produce more energy than they consume. It appears these competitions are on their way to achieving the aforementioned targets as they have garnered significant media attention. In 2009, the Solar Decathlon had over 900 million media hits and more than 300,000 visitors tour the Washington National Mall.[i]

Proposal and Design
The public sees only twenty teams at each competition, but hundreds each year apply to be part of the growing solar events. Every school draws up and submits a proposal of their vision for the competition. With a large technical review of the house, architectural renderings and a scale model included in the proposal, each submission is a comprehensive look at how they see the future of solar living. From the large group of applications judges for each competition must choose just twenty that they believe have the innovation, team cohesiveness and industry support to successfully demonstrate the future of solar energy.

Each home is designed and developed from the ground up as students work with industry leaders to learn the fundamentals of building design and construction. Using computer aided design (CAD) software every system and structure in the home is drawn and simulated. Teams are encouraged to develop and test new designs and technologies to implement in the home. Pulling from the active research on their respective campuses each team brings something fresh to every competition and is rewarded for it by the judges. In the twelve to fourteen months that it takes to design their thousand square foot home, team members see real world application to their studies and research-assisted solutions to day-to-day problems.

A large component of these homes is their ability to be moved. A house is typically thought of as a permanent feature added to the landscape, but in the case of the Solar Decathlon each house must be shipped around the world. This, of course, raised a wonderful design conundrum: how do you design a structure that must incorporate all the systems required to keep its occupants comfortable (climate, water, electrical, etc.) but at the same time have it ready to come apart and packaged to move? Every year teams solve this challenge in different ways with a variety of modular designs. This year at SD Europe three teams took this problem to heart and developed some incredible solutions:

SMLhouse—S-Small, M-Medium, and L-Large-- is a strong proponent for developing flexibly functional dwellings for its homeowners. This linear growth system is perfect for creating temporary housing or permanent residencies. With a single base module a user can custom design a residence based on their needs.

Solarkit takes this design concept even further by allowing for more potential combinations as each piece of “furniture”, or module, can be removed or rearranged upon the request of the prospective homeowner. With more of an IKEA take on home design users can select from a catalogue of modules to fully customize their structure.

The Armadillo Box is a project shaped and designed after the armor-plated animal. Not only can this house power an electric car, it can also be modified to acclimatize successfully in different locations and cultures.

Much like the infinite possibilities a modular design has, the general market for these homes can be integrated in numerous ways as well. Here are a couple practical applications for modular design.

1. If you do not have the budget for all of the modules, you can purchase several of them first, and add on others when you have sufficient funds.
2. Prefabricated and modular houses can be deployed in emergency situations for temporary living.  For example, Green Horizon, a company based in San Francisco, makes homes that can fit perfectly in a shipping container and be completely set-up within an hour.

Notable Technologies/Features
While not every team could procure SD Europe’s official accolades, each house had its own clever technologies and features that the public could appreciate. Team Berlin built custom-made black solar thermal cooling panels. Placed on the north sloping roof of its Living Equia house, water is pumped through the panels at night radiating heat and cooling the liquid down. This water is stored and then pumped through interior radiant cooling panels during the day to regulate interior home temperature during the warmer parts of summer.

The University of Nottingham developed a solar chimney and misting system to cool their home. A central two-story atrium collects the warm air in the house, where the air is subsequently cooled by water misters and disseminated back through the home.

Aalto University’s Luukku House featured custom-built frameless quad-pane windows that are sunk into the walls. These windows had the highest R-values of any on the Villa Solar. These along with wood-wool insulation made the house net-zero in its native Helsinki environment and net positive by four-fold in the warmer Madrid climate.

Team Wuppertal designed a superbly integrated solar water heating system. Evacuated tube solar thermal collectors were placed vertically on a south facing wall. At the base of this wall a small reflecting pool was built. This pool not only preheated the water entering the solar thermal collectors, but also reflected additional light onto the collectors to help heat it as well.

Solar thermal collectors on south-facing wall

The University of Applied Science in Rosenheim’s Ikaros house developed a couple new systems. The team developed its own software to control all of the systems in its home, complete with a touch-screen interface self-described as the “iPod of your home.” The system received its name because the climate, light, and window settings can be saved as “playlists” depending on the homeowners’ desires.

The Tongji Team used raw bamboo as its superstructure for the house. This material is abundant because it grows quickly, and is seen as a rapidly renewable resource. Bamboo lowers the weight of the house and the capital cost of construction as well.

It remains to be seen whether some of these innovations will enter the market successfully. Nevertheless, it is certain that continual research and experimentation will provide more traction for solar technology integration to gain market share and awareness in the housing industry.

Construction and Testing in Madrid
SD Europe had teams construct their homes in the shadows of the Royal Palace along the banks of the Madrid River in what was dubbed “The Solar Villa”. Arriving in early June, teams were allocated two weeks to completely assemble their homes; June 18^th was SD Europe’s official opening to the public. By the time the homes were up and ready to collect solar energy the sun had arrived, but the construction phase was plagued by constant rain. This caused a couple teams to lose time, and they were not ready for the Solar Villa’s official opening. As we enjoyed the now hot and sunny Madrid weather the disparity between teams who were ready and those who were not became noticeably larger. This trend would later continue onto the scoreboard with easy predictions of teams who performed unfavorably.

Even though each team would have constructed and tested their home before arriving in Spain, the true test of the house and its systems would be during the public viewing. With the main focal point of the competition running from June 18^th to the 27^th, team’s houses were scrutinized not just by the judges but by the public at large. SD Europe’s public relations team did a spectacular job, which was reflected in the number of people taking time out of their day to visit the Solar Villa and stand in ever-growing queues to visit the seventeen homes.

The Solar Decathlon is named as such for the ten different sub-competitions each home is judged on:

• Architecture
• Construction
• Engineering
• Solar systems and hot water
• Energy balance
• Comfort conditions
• Usage
• Communications and social media
• Industrialization and market viability
• Innovation
• Sustainability

Professionals from the industry in each category are invited to judge the homes. Every sub-competition has a winner, but the overall winner of the Solar Decathlon is the team that performs well in all ten sections. At this year’s SD Europe the overall winner was Virginia Tech’s Lumenhaus, with the People’s Choice Award going to the University of Florida’s Project Re: Focus.

Lumenhaus: SD Europe Overall Winner 

The Future
We strongly encourage everyone to follow the upcoming Solar Decathlons. While a home is a large capital expenditure, there is the potential for a real return on investment with the implementation of energy producing solar systems. Expect to see net-positive energy buildings go from prototypes to mass production in the near future.  Who knows, perhaps your next home will be part of a budding sustainable neighborhood. To quote our Project Manager, Nate Preston, now is the time to “demand more from your home.”

[i] “About Solar Decathlon,” July 6, 2010 <http://www.solardecathlon.gov/about.cfm>

About the Authors
Justin Cullen (Logistics and Water Systems Manager), Sean Seemann (Mechanical Systems Manager), and Richard Tam (Finance Manager) are members of the Queen’s Solar Design Team, a multidisciplinary group of undergraduate students from Queen’s University in Kingston, Ontario. The team’s goal is to design, develop and build a net positive energy home in the coming years to compete in the Solar Decathlon.