Brattle Experts Assess Value of Regional Resource Adequacy Footprints for Utilities in the Western Electricity Coordinating Council
Prepared for a group of utilities in the Western Electricity Coordinating Council (WECC)
In a new report prepared for a group of utilities in the Western Electricity Coordinating Council (WECC), Brattle experts studied the comparative generating capacity needs of several regional resource adequacy program footprints. As analyses by the existing Western Resource Adequacy Program (WRAP) have shown, the diversity of a large regional footprint offers significant resource adequacy benefits. Programs like the WRAP also establish a common capacity accreditation of generating resources, which can further reduce costs by facilitating capacity trades.
The Brattle team was engaged to analyze the extent to which the Non-CAISO portion of the EDAM region may offer WRAP-like resource adequacy benefits. Brattle experts applied WRAP’s methodology for assessing zonal resource adequacy needs and resource capacity accreditations to both the WRAP region and the anticipated Non-CAISO EDAM footprint for the winter 2027/2028 and summer 2028 binding seasons. The analysis showed that the non-CAISO EDAM footprint offers significant resource adequacy benefits, on par with and possibly exceeding the resource adequacy benefit of the current WRAP footprint.
Key takeaways include:
- When applying the WRAP approach to resource adequacy, estimated Summer 2028 Planning Reserve Margins (PRMs) are similar for the WRAP subregions and the anticipated Non-CAISO EDAM footprint due to similar reliability risks.
- Under the WRAP approach, estimated Winter 2027/2028 PRMs are somewhat lower for the anticipated Non-CAISO EDAM footprint because of higher regional diversity.
The Brattle team also identified potential enhancements to the WRAP methodology, such as considering transmission limits within the footprints, temperature-dependent thermal outage rates, and improved hydro and weather modeling.
The report, “Regional Resource Adequacy Program Footprint PRM Study,” was authored by Brattle Principal John Tsoukalis, Senior Consultant Kai Van Horn, Senior Energy Associate Linquan Bai, Senior Energy Specialist Evan Bennett, Energy Specialist Bo Li, and Energy Analysts Jack Kalinski, Alison Savage Brooks, and Drew Kassman.
The study was prepared for Balancing Authority of Northern California (BANC), Idaho Power, the Los Angeles Department of Water and Power (LADWP), NV Energy, PacifiCorp, Portland General Electric (PGE), Public Service Company of New Mexico (PNM), Seattle City Light, and the Sacramento Municipal Utility District (SMUD).
