Ancillary services support the reliable operation of the transmission system as it moves electricity from generating sources to retail customers.
PJM Interconnection currently operates two markets for ancillary services:
- Synchronized Reserve supplies electricity if the grid has an unexpected need for more power on short notice.
- Regulation is a service that corrects for short-term changes in electricity use that might affect the stability of the power system.
In addition, Black Start Service supplies electricity for system restoration in the unlikely event that the entire grid would lose power.