Leaving your air conditioner on full blast all day might soon come with a little less guilt, thanks to an alloy developed by the University of Maryland. The "thermally elastic" material could allow air conditioners to run 175% more efficiently.

The new metal serves as a solid coolant, as opposed to the traditional (and environmentally nasty) liquid coolants found in commercial and residential air conditioners. If implemented, the new super-efficient system could reduce US carbon emissions by 250 million metric tons per year, and keep liquid refrigeration agents out of landfills and backyards. The next step for the project is making use of $500,000 in federal stimulus cash to advance the working prototype into commercial production. [University of Maryland via Inhabitat]