The legislature overrode the governor’s veto, canceling Duke Energy’s interim carbon reduction goal of 70 percent by 2030. Proponents say it will lower energy costs, but volatile gas prices and escalating costs for gas turbines could have the opposite effect.By Lisa SorgDuke Energy can now backslide on its legally mandated carbon emissions reductions, offload a greater share of fuel costs to residential customers and charge ratepayers for financing costs of planned new power plants even if they’re never built.