FLAGSTAFF, Ariz. — Federal environmental regulators are praising Northern Arizona University for its use of renewable energy.

The Arizona Daily Sun reported that the Environmental Protection Agency announced last week that NAU is the largest consumer of renewable energy in the Big Sky athletic conference.

According to the EPA, NAU used more than 8 million kilowatt-hours last year in renewable energy.

That comes out to 13 percent of the school's yearly electricity usage, up from 10 percent in 2013.

NAU officials said the school purchases renewable energy credits.

The university pays a premium for the green energy. The payment goes toward developing and installing renewable projects around the country.

NAU's Office of Sustainability has set a new goal of having renewable energy supply 15 percent of the energy consumed.