Technology

"A tidy village dedicated to the future of green, solar-powered living has taken over the heart of the National Mall, where 20 teams of college students are vying to see who can build the most appealing energy-efficient home."

"Dow Chemical has unveiled a residential roof shingle in the form of a solar panel designed to be integrated into asphalt-tiled roofs."

"The Environmental Protection Agency detailed its plans on Tuesday for research into the possible health and environmental risks of nanomaterials, tiny substances that are finding growing use in products like sunscreens and industrial adhesives."

Straw, a century-old building material, is making a comeback as an eco-friendly choice for modern home construction.

"Green roofs are increasing in popularity across the US, especially in cities, where there's not a lot of space for gardens. In Washington, DC, the city government is promoting the practice for its environmental benefits."

NASA is taking water recycling -- something necessary for space travel -- to new heights.