Federal and state authorities are finding common ground on shielding ratepayers from the costs of grid upgrades and data center growth. But they still have to determine who should and will pay.By Aman AzharA new federal order could strengthen Maryland’s claim that its households and businesses have been unlawfully billed billions of dollars for transmission upgrades to serve out-of-state data centers. But it is unclear whether the Federal Energy Regulatory Commission’s recent directive, which requires six regional grid operators, including PJM Interconnection, to justify how they assign those costs or propose changes, will help Maryland recover money PJM already allocated to the state or will apply only to future cost allocations.