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Security Constrained Unit Commitment

Optimization that determines generating unit commitment schedules subject to security constraints.

Definition by NYISO

Source: 1 (p8, Version 8.0)

The SCUC produces the generating unit commitment schedule and Firm Transaction schedules for the next day’s operation. Factors considered by SCUC are:

  • Current generating unit operating status
  • Constraints on the minimum up and down time of the generators
  • Generation and start up bid prices
  • Plant-related startup and shutdown constraints
  • Minimum and maximum generation constraints
  • Generation and reserve requirements
  • Transmission facility maintenance schedules
  • Transmission constraints
  • Phase angle regulator settings
  • Transaction bids
  • Minimum and Maximum Energy Level constraints (for Energy Storage Resources (ESR) only)
  • Bid Beginning Energy Level for ESR (for ISO Managed ESR only)
  • Co-located Storage Resources (CSR) Scheduling Limits (Only for solar/wind Intermittent Power Resource (IPR) and ESR Generators that participate in a CSR). Aggregations comprised of ESR, Wind, or Solar only are not eligible to participate in a CSR.

Last modified: 2025-06-22

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  1. NYISO (2024). Manual 11: Day-Ahead Scheduling Manual. https://www.nyiso.com/documents/20142/2923301/dayahd-schd-mnl.pdf/0024bc71-4dd9-fa80-a816-f9f3e26ea53a ↩