Western Area Power Administration is in the business of moving power, as well as marketing it. Utilities transmitting non-Federal power may buy the transmission capacity remaining on WAPA’s system after we reserve enough capacity to deliver Federal hydropower to our long-standing, firm power contracts. Available transmission capacity is sold on our Open Access, Same-Time Information System.

WAPA offers three types of transmission services. Point-to-point service is transmission between points of receipt and delivery. Network integration transmission service delivers capacity and energy over WAPA’s system from a network customer’s designated resources to its designated load. Ancillary services support the transmission of capacity and energy from resources to loads while maintaining the reliable operation of the system.


Ancillary services support the transmission of capacity and energy from resources to loads to help maintain a reliable operation. WAPA ​offers ancillary services as part of its control area services.

The Federal Energy Regulatory Commission defines ancillary services as:

  • Scheduling, System Control and Dispatch—scheduling the amount of energy to be delivered, assigning load and ensuring operational security.
  • Reactive Supply and Voltage Control—maintaining correct voltage through adjustments to generator output.
  • Regulation and Frequency Response—following the moment-to-moment variations in the demand or supply in the control area.
  • Energy Imbalance—providing energy correction for any hourly mismatch between a transmission customer’s energy supply and demand served.
  • Spinning Reserves—providing immediate backup service from a reserve unit to serve load in case of a system contingency. (When the reserve unit is operating, it is spinning, thus the name spinning reserve.)
  • Supplemental Reserves—serving loads when a contingency exists; not available immediately to serve load but can be available within a short time.

Last modified on March 10th, 2023