Western Area Power Administration, an agency of the U.S. Department of Energy, CRSP Management Center. Links to Western's homepage.
Link to Western's home page
CRSP Home About CRSP Contact CRSP Customers Environmental Review—NEPA Financial Data Operations Planning & Projects Power Marketing Rates Rate Adjustments Transmission Ancillary Services Rates WAPA-137 Rate Order

Ancillary Services

Ancillary services are services that make the transmission system "work." They support transmission of capacity and energy from resources to loads while maintaining reliable system operation.

Ancillary services include:

  • scheduling, system control and dispatch service - schedules the amount of energy to be delivered, assigning load and ensuring operational security, among other tasks;
  • reactive supply and voltage control from generation sources service - maintains correct voltage through adjustment to generator output;
  • energy imbalance service - provides energy correction for any hourly mismatch between a transmission customer's energy supply and demand served;
  • regulation and frequency response service - follows the moment-to-moment variations in the demand or supply in the control area;
  • operating spinning reserve service - provides immediate back-up service from a reserve unit to serve load in case of a system contingency;
  • operating supplemental reserve service - serves load when a contingency exists; not available immediately to serve load but can be available within a short time.

We develop transmission agreements for these services and may modify them upon written notice to the customer. In some projects, customers can get credit on their own power bills if they receive the service from another source or supply it from their own load. If the resources are not available to provide these services, Western will offer to purchase the service and pass through the costs to the customer, plus administrative fees.


About Power Marketing Transmission Newsroom Business Policies
Products Plan contents OASIS News features Careers No FEAR act
Organization chart Plan processes Functions News releases Doing business Privacy policy
History General power contract provisions OATT Revisions Fact sheets Energy Services Accessibility
Financial information Rates and Repayment Interconnection Publications EPTC Adobe PDF
Power projects EPAMP Infrastructure projects   Federal Register Notices  
Customers Legislation/Regulation     Regions  
Defining the future IRP     FOIA  
Industry participation Hydro Conditions     Industry links