A statement from the department Thursday said it is responding to an executive order to reduce waste and pollution in federal operations.
It said it was on target to cut greenhouse gas emissions by 20 percent, reduce water use by 26 percent and use more renewable electricity by 2020.
The department said it exceeded a 2012 goal of using renewable energy for 5 percent of its electricity use.
"Meeting this  renewable energy goal will reduce pollution in our communities, promote American energy independence and support homegrown energy produced by American workers," the statement said.
President Barack Obama, in his 2011 State of the Union address, laid out a clean-energy target of meeting 80 percent of U.S. energy needs with clean sources by 2035.