Resource adequacy ensures there is enough available power to meet peak demand at all times. It is a key function of MISO. MISO serves as an intermediary between energy sellers and buyers in its region through the Planning Resource Auction. MISO’s resource adequacy construct complements the jurisdiction that regulatory authorities have in determining the necessary level of adequacy. It also works in concert utilities that provide demand forecasts that help drive the development of local and regional requirements. MISO began determining resource adequacy on a seasonal, rather than annual, basis in Fall 2022.
See BPM-011 Resource Adequacy for more information on resource adequacy and processes.
Seasonal Auction
Auction cycle will move from annual to seasonal auction (clearing all four seasons still once yearly).
Seasonal Accredited Capacity (SAC)
The thermal resource accreditation will be calculated seasonally based on each resource’s real-time offered availability during all hours and hours with the tightest operating conditions to effectively reflect the actual availability of resources during times when they are most needed. The calculation of SAC values will be enhanced to a more efficient, automated process in replacement of the current manual method for thermal type resources.
Not Changing:
The general process for auctions will not change.
Data required for each auction cycle will not change.
Development is currently underway. Enhancements are being released to MECT Customer Connectivity Environment (CCE) as they become available. Production release and implementation will coincide with the 2023-2024 Plan Year cycle to begin in September 2022.
| Date | Current & Upcoming Data Publication |
Data View Provided |
| Now Available in PRA Docs > PY23-24 | RA Hours | Sept 2019 - Aug 2022 (PY 23/24) |
| November 2022 | Initial Class Average Initial UCAP/ISAC Ratio (Draft) SAC Values |
Sept 2019 - Aug 2022 (PY 23/24) |
| December 15, 2022 | Final SAC Values | Sept 2019 - Aug 2022 (PY 23/24) |
PY = Plan Year
Training and knowledge resources are available through MISO Help and MISO LMS
Recently published references:
| How to Access Customer Connectivity Environment (CCE) KA-01319 |
|
Registrations in MECT
Registrations in MECT (Video Walkthrough) KA-01369 |
|
MECT Screens: Seasonal Accredited Capacity Displays Doc KA-01320 Seasonal Accredited Capacity Displays (Video) KA-01368 |
|
PowerGADS/GVTC Resources |
For questions and support please create a case through our Help Center.
The annual Planning Resource Auction (PRA) demonstrates sufficient resources and allows market participants to sell capacity, via an auction, to other market participants who may expect a shortfall. MISO sets the capacity requirements in its region for each season of the June 1 to May 31 time period.
MISO bases the region’s energy needs, including a planning reserve margin, on multiple studies including members’ demand forecasts for peak use. It determines the reserve margin from the annual Loss of Load Expectation study. MISO accepts auction offers the last four business days of March, applies constraints calculators, then approves or rejects the transactions within the first 20 business days of April.
The annual Regional Resource Assessment (RRA) uses publicly shared plans and goals of the region's electric utilities to develop a forward-looking view of the evolving resource mix across the MISO region. This collection of data provides utilities, state regulatory agencies, and MISO with better insight into the expected resource changes over the coming years. This, in turn, assists stakeholders with the critical information needed to plan the grid of the future and ensure the continued flow of reliable, low-cost electricity.
MISO scores generation sources quarterly to determine the net amount of transmission capacity MISO can reasonably expect from them. The Seasonal Accredited Capacity (SAC) score, in megawatts, accounts for various variabilities such as peak load, reserve margin, plant performance and plant history. For more information on SAC, visit our Knowledge Base.
Templates and Information
How to access Schedule 53 SAC Validation files in the Market Portal
How to Use the Resource Adequacy SAC Unit Template (Video)
MECT Tool Changes for Seasonal Accredited Capacity (Video)
RA Seasonal Accredited Capacity FAQ (KA-01373)
MECT Seasonal Accredited Capacity Displays (KA-01320)
SAC Resolution Process (KA-01376)
The following module is available in the Customer Learning Center:
Introduction to Seasonal Accredited Capacity
MISO conducts and issues resource assessments in advance of each season that evaluate potential resource adequacy risks for the upcoming season. These informational assessments evaluate projected near-term available capacity under probable and extreme peak load forecasts and historical generator outage conditions for each season. The assessments highlight potential issues in the upcoming seasons to help system operators and stakeholders prepare for potential strained system conditions and develop preventative actions.