When a generating resource comes online, it can be up to 15 minutes until the Market Participant receives a Dispatch Target from MISO.

This is because the Unit Dispatch System (UDS) must be able to produce a solution indicating that the Resource is online.  The prerequisites that the UDS will need to consider a resource as online are as follows:

  • Resource must have their output breaker closed; or, more accurately, have indications that it is closed.
    • As a result, the MISO State Estimator breaker status will solve as if it is closed.
  • Resource must have an absolute value of MWs in excess of 0.5MW.
    • Usually, 0.5MWs is enough to allow the MISO State Estimator to solve MWs at the Resource.  Sometimes, there may be some very minor residual errors between the MISO EMS Model and the Bulk Electric System, so additional MWs may be needed before the MISO State Estimator solves for a MW output on the Resource.
  • Ideally, the Resource should be sending MISO a non-zero Control Mode, but it isn’t a requirement before the UDS considers the Resource as online.
  • Finally, an exception to the second requirement: all Dispatchable Intermittent Resource is considered online anytime the state estimator breaker status indicates closed.

The MISO UDS uses the SCED algorithm to balance injections and withdrawals, meet Operating Reserve requirements, manage congestion, and produce LMPs and MCPs on a simultaneously co-optimized basis.  The Real-Time Energy and Operating Reserve Market clearing operates continuously on a five-minute basis.  The SCED runs every five minutes to develop Resource Dispatch Targets for the end of the next dispatch interval.
Since this action is occurring every 5 minutes, the active State Estimator solution that the UDS is using for the current, and possibly the next case, may not have a Resource that just came online.  The prerequisites will need to be made before the UDS can include it in its case.  Therefore, MP’s should anticipate that if their Resource came online at a specific time, then they should expect to see their first Dispatch Targets to show up 5-10 minutes later.
BPM-002 Energy and Operating Reserve Markets Business Practices Manual


Level 100 Real Time Operations
Level 100 IMM Uninstructed Deviation