Resources in MISO are dispatched using a Security Constrained Economic Dispatch (SCED) algorithm.
Security Constrained Economic Dispatch (SCED) is defined as:
"An algorithm capable of clearing, dispatching, and pricing Energy, Operating Reserve, Up Ramp Capability, and Down Ramp Capability in a simultaneously co-optimized basis that minimizes Production Costs and Operating Reserve Costs while enforcing multiple security constraints. The algorithm keeps the commitment of Resources fixed in the dispatch."
The Real-Time SCED Algorithm Provides Resource Dispatches that:
Minimize production costs of already-online Resources that are needed to balance Load with Supply
Procure Operating Reserves, while honoring all limitations, including transmission constraints, resource ramp/limit constraints, self-schedules, etc.