#2: Harvard University

This Ivy League exemplar is a front-runner in getting the most structures certified by or registered for the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) standards. A $12 million loan fund provides interest-free financing for ecofriendly projects—such as installing motion-sensor lights in classrooms and converting a recycling truck to run on waste vegetable oil from one of the dining halls. Such efforts generate enough savings to pay back the loan.

Check out Harvard's Green Campus Initiative.

Photo by Kris Snibbe/Harvard News Office