Like solar installers across much of America, Mark Hagerty is adapting to drastic changes in the economics of his business. His state, Michigan, is one of many that are cutting the rates rooftop solar owners receive for selling excess power to the grid. “We’re going to do fewer jobs, and each job is going to be a smaller size,” said Hagerty, president of Michigan Solar Solutions, a solar installer based northwest of Detroit. His comments echo concerns now being voiced by solar installers in many states as new rules take effect. The changes are part of a flurry of activity across the country as regulators and legislatures in almost every state referee a showdown between powerful utilities and a rooftop solar industry offering options that are more affordable and popular than ever. The results run the gamut, from a solar-friendly bill that became law in Maine to one that will sharply reduce the financial benefits of solar in Kentucky. Amid the noise of competing proposals, a pattern is emerging: States are moving away from “net metering” policies that require utilities to pay solar owners the full retail rate for excess electricity sent to the grid.