In Minnesota, an industry group says the rules will shrink available space for solar panels by at least 20%.
Project Tundra represents a potential harbinger for the technology that could extend the viability of coal power.
An industry group had already been pushing for an extension of a popular solar incentive program set to end in 2021.
Safety is the main goal, but long-term pollution benefits could be seen as streets become safer for walking and biking
The proposal recently received a $50,000 prize from a National Renewable Energy Laboratory solar manufacturing contest.