EcoMax and Dispatch Setpoint are set in Real-Time Unit Dispatch System (RT UDS) for Dispatchable Intermittent Resources (DIR) when the it is on-control (control status = 1). The logic used for EcoMax and Dispatch are as follows:
1. If the Market Participant (MP) submitted a load forecast, RT UDS will use the MP submitted forecast (timing and values are validated).
2. If the MP does not submit a forecast and MISO’s forecast is available, RT UDS uses the higher value between State Estimation (SE) value and MISO forecast.
3. If there is an operator EcoMax override, the SE value determined above is capped at the override value.
1. If the unit’s offer price is less than Locational Marginal Price (LMP), the unit is “in the money”, and the MP submitted EcoMax is used.
2. If the unit’s offer price is greater than LMP, it is dispatched down, using the Economic Dispatch determined value (Bounded by MP submitted EcoMin and EcoMax limits and the unit ramp rate).
3. If the unit’s offer price is the same as LMP, it is a marginal unit and is dispatched down, using Economic Dispatch determined value
When the Dispatch Setpoint is less than EcoMax and the DIR unit is on control, the unit is dispatched down. This t is usually caused by the unit’s offer price being greater than or equal to LMP.
Reference: BPM-002 Energy and Operating Reserve Markets (See DIR Forecast Maximum Limit)