The University of Pennsylvania leads the nation's colleges and universities in the purchase of green power, specifically wind power, the Environmental Protection Agency has announced.

Penn was at the top of 40 colleges and universities that are EPA "green partners," and EPA officials said it was highly unlikely there was another college that did more.

The Ivy League school had led the nation for several years, but was overtaken by New York University in 2007.

"We didn't like that," said Dan Garofalo, Penn environmental sustainability coordinator and senior facilities planner.

Though it does not literally buy energy from wind turbines, which is all but impossible, the university this year bought renewable-energy credits equal to 192.7 million kilowatt hours of wind energy, which accounts for about a quarter of Penn's energy consumption, according to Garofalo.

The purchase allows for more wind energy to enter the region's power grid.

Up from 112 million kilowatt hours last year, this year's purchase is the equivalent of eliminating the carbon-dioxide emissions of more than 25,000 vehicles, the EPA estimated.

With nearly 35,000 employees at its education and health-care campuses, Penn is the largest private employer in the city. The university, which covers 280 acres in West Philadelphia, enrolls nearly 24,000 full- and part-time students. (The green-power initiative does not include the health-care system.)

Two other local universities also were cited as being among the largest green-power purchasers among their conferences.

Penn State led the Big Ten Conference with 83.6 million kilowatt hours, and Rowan University in New Jersey topped the New Jersey Athletic Conference with 10.4 million kilowatt hours.

"We're grateful for the EPA's recognition of our environmental efforts," Rowan president Donald Farish said in a prepared statement. "We remain committed to being good stewards, and we look forward to exploring further means of lessening our university's impact on the environment."

Rowan's purchase is equivalent to the energy required to power nearly 1,000 average American houses each year.

Some universities have put more emphasis on reducing energy consumption rather than converting to green power.

Princeton University recently announced a plan for greenhouse gas emissions reduction, resource conservation and research, education and civic engagement on the issue.

"The university deliberately chose to engage in projects that directly affected campus rather than 'offset projects' that are a feature frequently included in other sustainability plans," said Emily Aronson, a spokeswoman for Princeton.

Penn's Garofalo acknowledged the different approaches, but said that Penn was working on energy conservation, as well as expanding its use of renewable-energy sources.

"We wanted to get into the renewable-energy market and make a big impact," he said. "It's a new world, and I'm thrilled that the university is making a lot of progress."

Penn also has the distinction of being among the top 25 purchasers of green power nationally, among all the organizations the EPA tracked.

Penn plans to develop a plan by next year to neutralize the campus' carbon footprint over the next several decades, he said.

The university has hired an intern this summer to look into other ways the campus can use more renewable energy, such as solar, he said.

Inquirer staff writer Sandy Bauers contributed to this article.