RESERVE is E3’s tool for determining dynamic ancillary services needs of highly renewable electricity grids. It uses intelligent selection of causal variables to help grid operators predict reserves needs and better manage forecast error and short-term variability in load and in wind and solar production.

RESERVE calculates system reserve needs as a function of historically observed forecast and actual profiles of load, wind, and solar. It also separates reserves into multiple types that are consistent with differing generator commitment times. Outputs from RESERVE can be tailored to provide customized, dynamic forecasts to help system operators integrate larger amounts of wind and solar power.

• RESERVE was used to calculate the benefits of “flexible solar” in E3’s award-winning 2018 study for FirstSolar, “Investigating the Economic Value of Flexible Solar Power Plant Operation.” The study, which analyzed four modes of operating solar plants in Tampa Electric Company’s service territory, found that allowing solar to provide ancillary services in both upward and downward directions produced the greatest economic value, and that benefits increase as solar penetration increases.
• In 2019, RESERVE was used to calculate ancillary service needs for 14 Western Interconnection balancing areas in the California Independent System Operator (CAISO) Extended Day Ahead Market (EDAM) project, which seeks to improve market efficiency and more effectively integrate renewable resources by optimizing day-ahead unit commitment and scheduling across a larger footprint. The balancing areas modeled by RESERVE represent approximately three-quarters of total interconnection load.
• RESERVE is also being paired with E3’s RESOLVE model to assess costs of deep electrification and integrating new wind and solar capacity in E3’s support of the California Public Utilities Commission in the CPUC’s 2019-2020 integrated resource planning (IRP) proceeding.

Dynamic solar day ahead reserve profile generated by RESERVE