California ISO addresses power price spikes in new EIM tariff proposal
The California Independent System Operator is proposing tariff revisions aimed at ending unexpected price spikes, or “infeasibilities,” that have occurred in the Western energy imbalance market after it started in November.
“The CAISO is confident that implementing this proposal will substantially ameliorate the remaining infeasibilities encountered in the PacifiCorp balancing authority areas, such that the percentage of remaining infeasible intervals in the energy imbalance market will not be excessive [compared with CAISO’s internal markets and other regional transmission organizations markets],” the grid operator said in a Wednesday filing with the Federal Energy Regulatory Commission.
In April, CAISO offered a set of proposed changes to address a key problem causing the “pricing excursions,” but last month FERC said it couldn’t evaluate the proposal until the grid operator filed detailed tariff revisions.
The EIM price spikes occurred because the CAISO market system was unable to recognize capacity that PacifiCorp, the first utility to join the EIM, was holding in reserve to meet potential needs, according to the grid operator.