The plans gearing up here bear consequences far beyond these two cities: The Ford plan reflects an ambitious vision that unites the techno-solutionist and urbanist wings of the sustainability movement—cutting-edge energy conservation and generation within a walkable urban village—with an additional emphasis on affordable housing and creative-class economic development.

But there’s been significant pushback over the shape of this site. The project would be built in a highly desirable neighborhood of mostly single-family homes, where the city’s historical urban fabric gradually shifts to upscale post-war suburban-style development. Neighborhood foes of the plan worry about density and traffic, while backers cite the city’s need to build more affordable housing, address economic inequality, and raise property tax revenues. As with similar NIMBY/YIMBY (“Yes In My Backyard”) standoffs in other cities, there’s a distinct generational divide over the issue, with younger St. Paul residents (as well as the city’s new 39-year-old mayor, Melvin Carter) tending to support the plan.

Another key question: If and when this green city-within-a-city gets built, can it really meet the ambitious efficiency and affordability goals its planners now envision?

The Hard Road to Net Zero

What sets the Ford site project apart from most other brownfield redevelopments around the country is its resolve to become one of the first net-zero energy communities in America—all the power consumed would be generated from renewable sources on site. It’s been named one of six Zero Energy Districts selected for a US Department of Energy accelerator project, launched in partnership with the National League of Cities to offer assistance for sustainable innovations. (The others are in Fresno and Huntington Beach, California; Buffalo, New York; and two in Denver.)

Net-zero will be a tall order in Minnesota, where freezing winter temperatures demand big energy inputs for heating. “I think the city has set up progressive energy efficiency and sustainability goals,” says Kaitlin Veenstra, an architect focused on green building at Ryan Architecture + Engineering. (Note: The company is an affiliate of the developer Ryan Companies, but this interview was conduced prior to Ryan’s direct involvement in the Ford site.) “The question is whether it’s financially viable.” Veenstra expresses cautious optimism, based on recent progress she’s seeing in green technology and financial support for sustainable initiatives.

To pull off this feat of green building, the development will need more than just hyper-efficient structures. “On a recent study of the Ford site, energy-efficient buildings can get you 80 percent of the way to net-zero,” says John Carmody, founder of the University of Minnesota’s Center for Sustainable Building Research. To get the rest of the way, the community will be equipped with a lot of solar panels—the cost of which has plunged 79 percent over the past decade—plus other efficiency tools.

One key feature of the plan is a district energy system, in which the heating, cooling, and hot water needs for a network of customers are served by piped-in hot and cold water. Such systems are common in European cities but still a bold idea outside of a few downtowns in the U.S. “It’s tough to get a single building to net-zero energy, but when you tie them together, it’s easier,” says Ken Smith, a consultant on the project and CEO of District Energy St. Paul, which has heated and cooled downtown St. Paul since 1983. The Ford site would also utilize one of the first Aquifer Thermal Energy Storage (ATES) systems in the U.S. An energy-saving technology popular in the Netherlands and Scandinavia (where it’s used at Stockholm’s main airport), ATES pumps groundwater—which essentially remains the same temperature year-round—out of deep aquifers to heat and cool buildings.