Multi-stage generating unit modeling

The California ISO is developing software functionality for modeling multi-stage generating units, such as combined cycle generating plants. These units pose particular challenges with modeling and dispatch because they have multiple configurations in which they can operate and forbidden regions in which they cannot operate. The ISO seeks to review with stakeholders the key policy issues that arise with modeling these units, and to maintain an open dialog as implementation of the multi-stage generating functionality goes forward. The ISO is developing rules for the transition costs specified in the multi-stage generating transition matrix. These mitigation rules to balance flexibility and prevent economic withholding are part of the Bidding and Mitigation of Commitment Costs stakeholder initiative.