Probabilistic planning reserve margin studies at the California ISO

This paper provides an overview of probabilistic planning reserve margin studies at the California Independent System Operator. Currently, load serving entities in the State of California, with its retail load under the jurisdiction of the California Public Utility Commission, are required to procure reserve level at 15 - 17 percent. However, the requirement is deterministic in nature. The California Independent System Operator, which controls 80 percent of the state´s electrical load, is investigating the use of probabilistic planning for planning reserve margin of the load serving entities under its operational control. The study results are shared with the California Public Utility Commission and the California Energy Commission for consideration of using the probabilistic PRM in the future.