[Editor's Note: This article is part of our ongoing coverage of Solar Decathlon entries leading up to the event's kick off on Sept. 23.]
The University of Hawaii built Hale Pilihonua for the 2011 Solar Decathlon, specifically designed for the tropical Hawaiian climate and for middle-income buyers looking for a sustainable home. Hale Pilihonua is a semi-monocoque house, which means that instead of an interior structure holding up the house, the exterior, or shell, is the load-bearing component.
The shell is made of bio-based, fiber-reinforced polymer that is strong yet lightweight, and stands up well in the event of rot, termites and floods. In fact, the house is so lightweight that it can even float in case of flooding, which is a common occurrence in a tropical environment like Hawaii’s. The shell also provides a tight envelope to maintain inside temperatures and reduce heating and cooling energy consumption. Low-E glass in the windows also prevents heat loss during the cooler nights.
Louvers on Hale Pilihonua’s exterior can be opened and shut as needed to let in or keep out daylight. Energy-collecting PV panels are water-cooled, and solar thermal collectors provide heat for domestic hot water. Energy can be stored in the house thanks to the integration of phase-change materials. Inside, sensors are in place to detect occupancy in rooms and adjust lights and other electronics accordingly. An aquaponic system is featured in the house’s interior, allowing residents to grow their own fresh produce, in addition to filtering the air.
Unfortunately, due to financial and other complications, Team Hawaii announced its withdrawal from the competition. The team still values the research they have completed, though, and plans to participate in the next Solar Decathlon, in 2013.