Home Stakeholder Engagement Issue Tracking Dispatchable Intermittent Resource (DIR) Modification

Issue Tracking Details

Dispatchable Intermittent Resource (DIR) Modification (IR040)

Last Modified - 01/22/2020

Modify business and settlements rules to improve incentives and enable more efficient participation of DIRs in MISO's economic dispatch process.

  • Perform analysis to determine appropriate alarming, notification, and replacement procedures, including any necessary tariff provisions to implement accuracy and performance standards, to validate market participant Forecast Maximum Dispatch submittals.
  • Enhance persistence forecasting to better reflect ramping capability of DIRs.
  • Consider a modified excess energy threshold for wind resources that would allow these resources more latitude to exceeds its dispatch level (i.e., its forecasted output) when it will not cause congestion.
  • Modify the Excessive Energy settlement to help balance the Excessive and Deficient energy settlements that wind resources face associated with forecast errors.


MISO’s Tariff requires Market Participant’s Offers reflect the known physical capabilities and characteristics of Generation Resources, including Forecast Maximum Limits for Dispatchable Intermittent Resources (DIRs). Other than ensuring that forecasts are timely, MISO’s Tariff does not require validation of the accuracy of wind suppliers’ forecast used to develop dispatch instructions for DIRs. In 2016, certain supplier wind Forecast Maximum Limits were consistently biased and many that were consistently more than 10 percent over-forecasted and were utilized to develop dispatch instructions. Because the MISO dispatch uses these forecasts as the dispatch maximum, the lack of accuracy or performance provisions makes the MISO energy dispatch subject to chronic shortfalls related to the over-forecasting. Additionally, over-forecasting can lead to inaccurate assumed system flows that result in inefficient congestion management.

All real-time wind forecasts are either completely reliant on "persistence" based forecasting or heavily dependent on "persistence" based forecasting. “Persistence” forecasting is a forecast of what is currently being produced. This yields to wind appearing to not follow dispatches when the wind is either ramping up or down due to the inability to properly forecast wind ramps in real-time.

DIR wind resources in MISO have a strong incentive to over-forecast their output in real-time. Under the current rules for all MISO Resources, Excessive energy is paid the lower of LMP or the Resource offer. For most conventional resources this is a reasonable outcome and provides reasonable incentives. For wind resources, however, their offers often reflect a Production Tax Credit payment opportunity cost so their offer prices are often in the range of negative $30/MWh. Hence, the Excessive Energy settlement for wind resources is far more punitive than the Deficient Energy settlement rules.



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Energy Markets
Reliable Operations

Advisory Committee Priority

Improve market efficiency

Guiding Principles

Support an economically efficient wholesale market system that minimizes cost to serve load

Focus Area

Enhance unit commitment and economic dispatch processes


Assessment: Voted into Market Roadmap Initiative List at 6/2/2015 Market Roadmap Workshop IMM Recommendation #2016-7 IMM Recommendation #2016-8

Comments: Potential software and/or procedure change for real-time market.




Which market products or systems does this impact?

Assessment: Energy

Comments: Real-Time Energy Markets

How Many Megawatts Are Directly Affected?

Assessment: All real-time dispatch MWs

Comments: Dispatch of units with fast ramping capability would likely be affected the most.

Implementation costs and other costs



Production Cost Savings



Other Benefits






Relationship to Other Initiatives



Potential Fast-Track Project

Assessment: No

Comments: Communicated at September 1, 2015 MSC.

Reliability Due Diligence





This issue was completed along with IR030 - Tighten Thresholds for Uninstructed Deviations. FERC accepted that Tariff filing on 1/25/2019.


Included new 2016 IMM recommendations