This year’s Solar Decathlon student design competition showed off new technologies and unique innovations in many areas, including alternative energy, passive heating and cooling, and water conservation and reclamation.

Sponsored by the Department of Energy, the biennial Decathlon is a program that challenges collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive.

From Sept. 23 to Oct. 2, 19 teams and their solar-powered houses competed in 10 categories (each worth 100 points) that included engineering, hot-water generation, affordability (a new category this year), market appeal, energy balance, and architecture.

This year’s winner, the University of Maryland’s WaterShed house, was inspired by the Chesapeake Bay ecosystem. The nearly 900-square-foot home is made of two rectangular sheds that form a split butterfly roofline which maximizes solar-energy generation and collects rainwater along a central axis. The two sheds are connected by a third, smaller module that houses the bathroom. Rainwater collected from the roof via the central axis mixes with the house’s greywater from the shower, clothes washer, and dishwasher, in constructed wetlands located under the bathroom and along the decks.

For the best designs and innovations from the competition, click on the slideshow above.