MISO said it will debut a new flag system within weeks to give stronger signals to generation owners when their units deviate from their dispatch instructions. 

The flag, planned for rollout June 3 in MISO’s unit dispatch system, would let operators know when their resources appear to be disregarding the RTO’s dispatch instructions. Along with the flag, MISO plans to provide a reason code, detailing the reliability reason its five-minute setpoint instructions should be followed.  

In an April 22 question-and-answer session for stakeholders, MISO’s John Harmon said the new codes behind uninstructed deviations should bring “clarity and context” to resource operators.  

RTO staff said units not sticking to MISO instructions create balancing and frequency issues that sometimes require out-of-market actions in the control room. Staff have said that modeled flows in MISO’s dispatch system are diverging more and more from actual flows, resulting in system operating limit violations, balancing issues and frequency deviations. (See MISO: Flag, Penalties Needed to Address Generators’ Uninstructed Deviation.)  

Harmon said the flag would apply to all generation resources except energy storage. Historically, MISO and its Independent Market Monitor have said wind generation sources are among the worst offenders when they’re ordered to dispatch down. 

The new system requires MISO to make software changes to its unit dispatch system. In addition to the flag, the RTO eventually plans to levy penalties in market settlements for units that ignore dispatch instructions.