Green Housing Comes to Mall for Solar Decathlon

The National Mall is considerably greener this month, but don't thank the park service.

The US Department of Energy is hosting its 4th "Solar Decathlon," a competition in which college teams from around the country compete to design and construct the most attractive, effective, and energy-efficient house. Twenty teams from places as far away as Spain have built houses on the National Mall between the Capitol and the Washington Monument.
The goals of the competition are wide-ranging, but the two primary purposes are to educate the student participants about the benefits of green energy, and to raise awareness among the general public about renewable energy and energy efficiency.

Houses were designed and constructed at their respective universities, taken apart, and shipped to Washington for the competiton, where seven days were given to each team to reconstruct their entry on the  National Mall.

WRGW had the opportunity to tour one of the most interesting entrants to the competition, a house constructed by the University of Arizona named the SEED [pod].

The SEED [pod] focuses heavily on the use of natural and passive processes accomplish things that typically require electricity in a normal home.  For example, the house features what was called a "Water Wall" to passively heat and cool the interior space.  An entire wall of the house consists of what is effectively a plastic water tank filled with water, which absorbs heat through sunlight during the day and releases it during the night.  The Water Wall may also be used to cool the house by reversing the process above.

The idea for the Water Wall was originally a student thesis.  Team members highlighted the feature as an example of how the project was a vehicle for student research.

While the project took advantage of the efficiencies gained through passive processes, including large doors to allow for greater airflow and a design that allowed for circulation of air inside the house, innovations in solar-generated electricity were also present.  The solar panels utilized by the team are bifacial, meaning that they absorb sunlight on both sides.  To aid in solar collection, the roof of the SEED [pod] is painted white, reflecting light back through the solar panels and taking full advantage of their potential.

Due to the remote nature of the competition and the transportation challenges involved, modularity was a theme among all houses, especially the SEED [pod].  In fact, the entry derives much of its name from the modular nature of its house: SEED is a reference to the owner's ability to expand the house as his or her life progresses.  The house is constructed of "modules" that typically represent a single function, such as a kitchen, bathroom, office, or bedroom.  The house is designed in a way that allows for easy addition of these modules, so that a family expecting its first child could simply purchase an additional bedroom instead of an entirely new house.  This prefabrication allows the team to both cut costs and waste when considering the possibility of widespread adoption of their project.

To cut costs even more, the structural elements of the project are designed to be easily manufactured by any local steel company, further cutting transportation costs.  Most structural pieces are created from folded flat sheet steel, and specific instructions on their cutting and folding have already been created by the team.  Ideally, the team wishes for the consumer to be able to purchase a house plan and have a local facility complete the fabrication.

The houses are open to the public October 9th-13th and October 15th-18th.  For more information, including judging scores and links to teams' websites, visit www.solardecathlon.org.