The United States Environmental Protection Agency named Northwestern one of the top 20 green-powered universities in the country for the sixth year in a row.

As of this October, NU is ranked seventh among universities nationwide for its usage of renewable energy resources.

The rankings are part of the EPA’s Green Power Partnership, which works with hundreds of organizations and institutions across the country to promote renewable energy usage. The organization’s quarterly rankings are based on institutions’ utilization of renewable energy certificates, on-site energy generation and green power products.

The University joined the program six years ago when it began purchasing renewable energy certificates from local wind farms, said Julie Cahillane, manager of refuse and recycling for NU. She said renewable energy accounts for 30 percent of the University’s total electricity usage.

In addition to the renewable energy certificates, NU’s rating is based on the energy produced from the solar panels on the Ford Motor Company Engineering Design Center, which were installed last year.

Since joining the Green Power Partnership in March 2006, NU has remained one of the top 10 participating universities. NU also holds the top spot in the Big Ten Conference, which is the second-highest user of green energy among all college conferences.

“We’ve pretty much established ourselves as a leader at the start, and maintained our top-tier position as a renewable energy university,” Cahillane said.

NU’s high energy usage has made the university a member of the Green Power Leadership Club, which requires that renewable resources account for at least 30 percent of overall energy usage for institutions such as NU that have an annual electricity usage of more than 100 million kilowatt-hours.

Rob Whittier, director of the Office of Sustainability, told The Daily earlier this month that renewable energy investments are beneficial both environmentally and financially.

“Most people I think now recognize that energy efficiency is the best payback economically and environmentally ahead of any other project,” Whittier said.

Cahillane said NU makes purchasing green power a priority because of the increasing depletion of other energy sources.

“There are limits in a lot of our environmental resources,” she said. “They’re finite resources. Supporting the expansion of these efforts and these power sources is a positive thing.”

— Lauren Caruba