The Koch brothers, anti-tax activist Grover Norquist and some of the nation's largest power companies have backed efforts in recent months to roll back state policies that favor green energy. The conservative luminaries have pushed campaigns in Kansas, North Carolina and Arizona, with the battle rapidly spreading to other states. Alarmed environmentalists and their allies in the solar industry have fought back, battling the other side to a draw so far. Both sides say the fight is growing more intense as new states, including Ohio, South Carolina and Washington, enter the fray. At the nub of the dispute are two policies found in dozens of states. One requires utilities to get a certain share of power from renewable sources. The other, known as net metering, guarantees homeowners or businesses with solar panels on their roofs the right to sell any excess electricity back into the power grid at attractive rates. Net metering forms the linchpin of the solar-energy business model. Without it, firms say, solar power would be prohibitively expensive. The American Legislative Exchange Council, or ALEC, a membership group for conservative state lawmakers, recently drafted model legislation that targeted net metering. The group also helped launch efforts by conservative lawmakers in more than half a dozen states to repeal green energy mandates. The group's campaign in [Kansas] compared the green energy mandate to Obamacare, featuring ominous images of Kathleen Sebelius, the outgoing secretary of Health and Human Services, who was Kansas' governor when the state adopted the requirement.