Weekly Power Markets Report: Grid Redesigns Amidst Early Winter Volatility

The operating week of November 29 through December 5, 2025, marked a crucial point for North American wholesale electricity markets, marked by the simultaneous implementation of major market redesigns, the solidification of long-term governance conflicts, and the start of early-winter meteorological stress testing. Across the continent, Independent System Operators (ISOs) and Regional Transmission Organizations (RTOs) faced a volatile environment where the ideas of energy transition—such as real-time co-optimization and quick interconnection reforms—clashed with the physical realities of grid operations. The main story for the week was the split in market pressures: the Western Interconnection grew more divided between the California ISO’s (CAISO) Extended Day-Ahead Market (EDAM) and the Southwest Power Pool’s (SPP) Markets+ offerings, while the Eastern Interconnection, especially PJM and New York ISO (NYISO), dealt with serious resource adequacy issues caused by rising data center loads and the retirement of traditional thermal baseload generation.