73 Pa. Stat. § 1648.4
If an electric distribution supplier or electric generation company provider sells electricity in any other state and is subject to renewable energy portfolio requirements in that state, they shall list any such requirement and shall indicate how it satisfied those renewable energy portfolio requirements. To prevent double-counting, the electric distribution supplier or electric generation company shall not satisfy Pennsylvania's alternative energy portfolio requirements using alternative energy used to satisfy another state's portfolio requirements or alternative energy credits already purchased by individuals, businesses or government bodies that do not have a compliance obligation under this act unless the individual, business or government body sells those credits to the electric distribution company or electric generation supplier. Energy derived from alternative energy sources inside the geographical boundaries of this Commonwealth shall be eligible to meet the compliance requirements under this act. Energy derived from alternative energy sources located outside the geographical boundaries of this Commonwealth but within the service territory of a regional transmission organization that manages the transmission system in any part of this Commonwealth shall only be eligible to meet the compliance requirements of electric distribution companies or electric generation suppliers located within the service territory of the same regional transmission organization. For purposes of compliance with this act, alternative energy sources located in the PJM Interconnection, L.L.C. regional transmission organization (PJM) or its successor service territory shall be eligible to fulfill compliance obligations of all Pennsylvania electric distribution companies and electric generation suppliers. Energy derived from alternative energy sources located outside the service territory of a regional transmission organization that manages the transmission system in any part of this Commonwealth shall not be eligible to meet the compliance requirements of this act. Electric distribution companies and electric generation suppliers shall document that this energy was not used to satisfy another state's renewable energy portfolio standards.
73 P.S. § 1648.4