The Ohio Supreme Court heard argument on the lack of limits for FirstEnergy’s credit rider.
Changing how benefits are calculated could undercut the justification for mercury standards and other rules.
Utility regulators ruled last month that customers who shop around for power suppliers are still eligible for net metering.
Ohio coal interests welcome the Trump administration proposal to narrow the definition of federal waters.
Consumer advocates say a proposed deal involving FirstEnergy’s earnings in Ohio ignores the interests of most ratepayers.