Most new renewable energy projects take the form of massive wind or solar farms. Ann Arbor, Michigan, is trying something different: a new city-owned utility is building a local power network within city limits, made up of solar microgrids and geothermal energy installed at homes and businesses.

“They’re creating a whole new model of energy delivery for a city,” says Mike Shriberg, a professor at University of Michigan’s School for Environment and Sustainability who lives in Ann Arbor.