An Optimization Methodology to Quantify the Benefit in The Western Energy Imbalance Market Participation

Abstract

The Western Energy Imbalance Market (EIM) administered by the California Independent System Operator (CAISO) has extended from two members in 2014 to eight members today, with a reported benefit of over half billion dollars. A key element of this benefit estimate comes from the heuristic methodology the CAISO adopted to calculate the counterfactual dispatch cost savings. Though fast and easy, the heuristic methodology offers little value to the EIM participant. This paper proposes a full optimization methodology from the market participant point of view to accurately quantify the EIM benefit utilizing a combination of publicly and privately available portfolio datasets. Multiple counterfactual scenarios can be constructed easily for in-depth generation portfolio analytics. A simple example will first be presented to understand all elements of the EIM benefit, and then an actual EIM generation portfolio will be tested to validate the proposed methodology.