This graphic illustrates a historic first. In December 2009, three plug-in electric vehicles (PEVs) began receiving payment for participation in the PJM Ancillary Services Market.

Shown below is the system in operation today, consisting of a one megawatt (MW) AES stationary battery trailer aggregated with three 18 kilowatt (kW) PEVs. The trailer and the PEVs are actively participating in the PJM Regulation Market that is used to maintain a grid frequency of 60 hertz. The batteries in the AES trailer and in the PEVs charge and discharge in response to a regulation signal that is sent every four seconds from PJM. The amounts shown are the payments made for each hour of participation.

The graphic shows specific values earned by the AES stationary battery system and the three plug-in electric vehicles for the day of October 31, 2009. When plugged in for the entire 24-hour day, each vehicle (18 kW) earns 1.8 percent of the revenue of the one-MW AES battery trailer. If only plugged in for 12 hours, the vehicles will earn only half of the amount reflected in the graphic.