CANTON — In another step toward a carbon-neutral campus, St. Lawrence University is now offsetting 15 percent of its energy use by supporting national wind power.

The college recently purchased 3,280 megawatt hours of green-certified credits through Juice Energy, a New York City-based electricity supplier, for this year.

That's enough to balance all of the Student Center's energy use, and half of the energy consumed in the Johnson Hall of Science.

"Sustainability is not successful unless it's a campus-wide movement, and that's what we're getting," said Louise E. Gava, SLU's coordinator of sustainability projects.

All electric energy goes into and comes from the electrical grid and is not separated by origin. So instead of ensuring that the college is getting power directly from wind turbines, energy credits show that it is paying to support that equivalent of its normal use in those sustainable sources.

By buying the credits, the college fulfilled a promise it made when signing the American College and University Presidents Climate Commitment. At the time, SLU vowed to obtain 15 percent of its energy from renewable sources within two years.

SLU's purchase also helps increase the market share of renewable electricity, Ms. Gava said.

She added that the college has a long way to go to reduce its carbon footprint, which will be helped by plans to conduct a comprehensive campus-wide energy audit and a study of using wood instead of natural gas as a heat source.

SLU is also applying for a grant to support a transportation management plan, which would encourage and facilitate carpooling. The college would also encourage biking and walking instead of driving.

But little changes often have a big impact in changing how the St. Lawrence community thinks about conservation and energy use, Ms. Gava said.

"People are learning behaviors here that they will take out for the rest of their lives. That has more long-term impact than signing a check and buying renewable energy credits," she said. "Any change we can get students and employees of the university to make in their personal life are so much more important, and those are not necessarily things we can quantify energy savings for."

For instance, the college now has "no mow" zones around campus, where groundskeepers are saving fuel — and emissions — by leaving the land be. They've also installed bluebird boxes there.

"To see people accepting a new aesthetic is thrilling. We're saving fuel and labor, and we're creating habitat, to be quite frank," Ms. Gava said. "It's just the right thing to do from a biodiversity standpoint."

Students have also responded enthusiastically to the college's "reuse basement," where they can pay garage sale prices for dorm room items that people leave behind in the spring. Freshman also take part in "Sustainability 101" sessions with Ms. Gava, to learn how they can be more energy-conscious in their college lives.

Dana Dining Center has stopped offering trays, in an effort to save the energy, water and soap used to wash them and to encourage students to waste less food.

The college also recently replaced all of its computers with Energy Star models, and added four Prius hybrids to its fleet.

"Little things make a big difference in the impression they make on students," Ms. Gava said.