PNNL

Abstract

The project described in the paper addresses the issue of mitigating additional intermittency and fast ramps that will occur at higher penetration levels of intermittent resources, including wind generation resources, in the Bonneville Power Administration (BPA) and the California Independent System Operator (CAISO) areas. The proposed Wide Area Energy Management System (WAEMS) addresses these additional balancing requirements through energy exchange between the participating control areas and through the use of energy stor-age and other generation resources. For the BPA and CAISO control centers, the new regulation service will look no different comparing with the traditional balancing services. The work conducted developed principles, algorithms, mar-ket integration rules, functional de-sign and technical specifica-tions for the WAEMS system. Main results obtained in the project are as follow: •Most suitable energy storage technologies for the pro-posed application include flywheel energy storage devices (ESD), pumped or conventional hydro power plants, and so-dium sulfur or nickel cadmium batteries. •A preferred WAEMS architecture was selected as an ag-gregate of a flywheel ESD and a pumped storage (or a con-ventional hydro plant). The aggregate to be integrated with BPA/CAISO automatic generation control systems. •An optimization control algorithm has been developed. It provides an excellent regulation signal following capability, helps to maintain a desired state of charge on the ESD, pre-vent violations, and keep the hydro (pumped storage) power output close to the most efficient operating point. •It has been shown that the WAEMS service could help to reduce the regulation requirement in BPA and CAISO con-trol areas by about 30% compared to a traditional regulation service with the same total regulation capacity.