The Southwest Power Pool (SPP) has asked the Federal Energy Regulatory Commission (FERC) to approve new tariff revisions that would implement separate planning reserve margins for the summer and winter seasons, replacing the current single margin for both. This move is designed to help utilities better prepare for seasonal differences; particularly as extreme winter weather events become more frequent.
SPP’s board has approved a 36% reserve margin for the 2026-2027 winter season and a 16% margin for summer 2026, recognizing the increased risks during winter months. These margins represent the backup capacity utilities must maintain to ensure grid stability. Along with the margin changes, SPP’s request to FERC includes three additional revisions: improving accreditation methods for performance and fuel assurance and establishing a winter-specific resource adequacy requirement. SPP has requested a FERC ruling by January 2025, with the changes to take effect in October 2025.
Read More:
PP board approves new planning reserve margins to protect against high winter, summer use