Carport Solar: Combining Parking and Clean Energy Production Pays Off

It’s not exactly a growing trend, although the University of Minnesota plans to build a second solar carport at its Saint Paul campus after the success of an initial project on the West Bank campus. Whether more carports will emerge depends on the economics of solar, the sustainability goals of potential clients and the availability of parking lots and ramps that could support projects.

But what about snow? People involved in managing solar carports say snow eventually melts or slides off into traffic lanes for easy removal by plows. They let nature take its course, wasting no staff time on brushing snow off panels. The dark colors of solar panels work to melt snow and ice off them, usually in at most a few days.

The university’s first solar carport—built and managed by Ameresco—opened at law school in 2018 and covers around 100 spaces of an existing parking lot, said Stennes. The continuous rows of solar panels for the 537 kilowatt (kW) project are slightly tipped at an angle, allowing snow to slide down one side into a traffic lane.

The university knew the solar canopy would make snow plowing more complicated, he added, but bobcats and pickup-mounted plows manage it almost as well as larger vehicles, he said.

Before adding two carports to municipal buildings, Red Wing rebuilt an aging surface parking lot. The city redesigned the surface lot to direct snow accumulation on panels to fall into landscaped areas filled with hearty plants rather than on the sidewalks leading to two public buildings, McCleary said.

The cheapest solar installation method is mounting panels on infrastructure attached to the ground, followed by those placed on rooftops, said Neville. The most expensive approach remains solar carports, though he believes they eventually pay for themselves and have an attractive dual use. 

Cooperative Energy Futures’ general manager Timothy DenHerder-Thomas said the A Ramp, part of the ABC Ramps complex, cost around a third more than a typical roof-top or greenfield solar project. The university paid a third more for the law school project, Stennes said, or about an extra $1 per watt in cost.

Is the additional cost worth it? The advantage for the university is that it has little land for solar, and not all rooftops can handle panels, Stennes said. Having solar arrays where people can see them helps bolster the university’s credentials as a place serious about reducing its carbon impact, he added.

“The university has sustainability goals and carbon reduction goals and these projects help us achieve those goals,” he said.

Sometimes the cost is worth it when no other alternatives exist. Red Wing discovered the historic designation of city hall killed a plan to add solar to it. The community development building’s roof was too weak to support panels. A pole shed-style structure at Red Wing’s public works facility would not survive strong winds, nor would any panels atop it. “The only alternative was carports,” said McCleary.