The term "energy efficiency" can mean virtually anything, depending on who's uttering the buzz phrase--greenies, lawmakers, even utility chiefs between clenched teeth. Among the variables ...

For our list, we looked at the 75 largest countries in terms of total gross domestic product, ranking them by "energy intensity" or BTUs per U.S. dollar of gross domestic product, the world ...

Pictures: Millennials Test Cute, Efficient Cars of the Future. At Shell Eco-marathon Americas, more than a thousand students vie to see who can build a car that runs on the least amount of fuel.

In light of National Energy Awareness Month, personal finance website WalletHub.com measured the energy efficiency of cares in 48 states.

Pictures: Nature Yields New Ideas for Energy and Efficiency. Drawing inspiration from schools of fish, termite mounds, and the photosynthesis of leaves, new technologies seek to produce cleaner ...

Luxwall, a Ypsilanti, Mich. based company, is focused on the "product development, scaling, and commercializing of innovative energy-efficient glass products and solutions for the built environment." ...