The Utility or Alternate Energy Supplier (AES), may offer the Customer a tariff that provides a low rate for off-peak charging and a higher rate for on-peak charging. The utility or AES must provide services to support energy supplied to customer PEV. These services include enrollment into a PEV program, PEV communications session binding, PEV energy billing, and PEV information services. The utility or AES will implement an enrollment system for Customers with a PEV including registration and commissioning. The utility’s or AES's Energy Services Interface (ESI) shall allow for the establishment of a communications session (communications binding), each time a PEV plugs in for charging.