PJM Generation Attribute Tracking System (GATS) is the credit registry selected by the State of Pennsylvania to issue alternative energy credits (AECs). A GATS account may be created by using the certification number assigned to a system once it is approved. Facility meter readings for registered facilities are reported in the GATS system. Each megawatt-hour (1 MWh = 1,000 kWh) of generation from a qualified alternative energy system corresponds to a number of AECs issued. Once issued by PJM-GATS, the AECs become available to transfer to buyers.