Wide-Area Energy Storage and Management System to Balance Intermittent Resources in the Bonneville Power Administration and California ISO Control Areas

This paper addresses the issue of mitigating additional intermittency and fast ramps that are expected to occur at high 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 participat-ing control areas and through the use of energy storage and other generation resources. For the BPA and CAISO control areas, the new regulation service would look no different than traditional balancing services. The work entailed the develop-ment of principles, algorithms, market integration rules, func-tional design and technical specifications for the WAEMS system. Main results obtained in the paper are as follow. The 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 aggregation of a flywheel ESD and a pumped storage (or a conventional hydro plant). The aggregate would be integrated with BPA and 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, prevents violations, and keeps 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 control areas by about 30% compared to a traditional regulation ser-vice with the same total regulation capacity.