2025 California ISO Summer Loads and Resources Assessment Stochastic Model and Multi-Hour Stack Model posted

The California ISO has posted its PLEXOS stochastic production cost simulation model and multi-hour stack model that was used to inform its 2025 Summer Loads and Resources Assessment. The Summer Assessment evaluates expected 2025 summer supply and demand conditions for the ISO balancing authority area (BAA). The 2025 models are available on our Seasonal assessments webpage.

The stochastic model was used to perform a probabilistic assessment of expected 2025 summer portfolio including all existing and planned resource adequacy (RA) eligible resources. A second perspective in the form of a multi-hour stack analysis for 2025 summer months (May – September) was also evaluated using the same portfolio of all RA eligible resources. Detailed assumptions, methodology and results are provided in the CAISO's 2025 Summer Loads and Resources Assessment Report and Technical Appendix.