Two Maine colleges have received a “green” thumbs up from one of the nation’ s most widely read collegiate guides.

College of the Atlantic and Bates College were among 11 schools singled out by The Princeton Review in the company’ s first-ever ranking of the country’ s “greenest” schools.

The ratings were released this week as part of the company’ s closely watched annual guidebook, “The Best 368 Colleges,” which ranks everything from colleges with the happiest students and best or worst food to the top party schools.

Participating schools were scored on three general themes focusing on the school’ s policies, the quality of life on campus for students from a health and sustainability standpoint, and how well the college prepares students for living an environmentally conscious life.

Each of the 11 schools — five of which are in New England — had to receive the highest possible score to make it onto the green “honor roll.”

College of the Atlantic in Bar Harbor was praised for the school’ s use of renewable energy for electricity and heat and new dorms that use composting toilets, metered showers and high-efficiency construction to minimize environmental impacts.

COA was also the first institution of higher education in the nation — and possibly the world — to become “carbon-neutral.” The designation means the school has reduced emissions of heat-trapping greenhouse gases and offsets any emissions it does produce.

“From its first day of classes in 1972, COA has practiced what it teaches, taking a leadership role in educating innovators to create a more sustainable, peaceful and just world,” The Princeton Review authors wrote.

Bates College in Lewiston, meanwhile, was lauded for the fact that 28 percent of the school’ s food budget goes to locally grown, natural or organic products. Bates also has bike-sharing and car-sharing programs, and recently opened two major buildings built to Leadership in Energy and Environmental Design, or LEED, standards.

COA President David Hales said it was nice for the school to receive recognition, but he pointed out that incorporating environmental responsibility into both campus life and curriculum was part of the college’ s original mission.

Hales said he believes the rating’ s inclusion in the guidebook reflects the growing interest among students in schools’ environmental policies and practices. Sixty-three percent of more than 10,000 students and parents surveyed by The Princeton Review said they would value having information on a college’ s environmental commitment.

Hales predicted the current trend is here to stay on college campuses.

“I think over the next 15 or 20 years, all of us are going to be dependent on renewable energy & all of us are going to be buying locally grown food, and the reason we are going to be doing that is it’ s the right thing to do economically,” Hales said.

COA also made it onto Forbes’ list of the top 10 green colleges and was ranked as the greenest school in the nation by, an environmental news Web site.

Other Maine institutions, while not listed on the “honor roll” of green schools, also are trying aggressively to lower their environmental footprint.

Several of the state’ s colleges, including the University of Maine System and Unity College, are pursuing goals of carbon neutrality. Others are constructing LEED-certified buildings, installing or exploring alternative energy systems and buying from local farmers.

Mark Tardif, spokesman for Unity College, said they were “extremely disappointed” that the institution was not contacted for the survey, considering that environmental education and sustainability are at the heart the college’ s mission.

The college’ s Unity House, billed as one of the first mass-producible green homes, has received national media attention. The school recently hired a full-time sustainability coordinator, and employees have sustainability criteria included in their performance reviews.

“Sustainability guides everything we do at the college to the fullest extent,” Tardif said.

The other nine schools on The Princeton Review’ s green honor roll are: Harvard College, Yale University, University of New Hampshire, Arizona State University at Tempe, Emory University, Georgia Tech, State University of New York at Binghamton, University of Oregon and University of Washington.