The impact on installation companies — many of them smaller, mom-and-pop operations — could be severe, if homeowners decide they can no longer afford going solar. Leon Keshishian, CEO of Civic Renewables, called the potential loss of tax credits “a killer” that could force him to cut staff at his company, which installs residential systems in Virginia, Maryland, Pennsylvania, Ohio and Florida. “It’s going to be incredibly challenging,” he said.