TECHNOLOGY AND APPLICATION OPTIONS FOR FUTURE BATTERY POWER REGULATION

The future electric power system is fraught with uncertainty, and many trends indicate greater constraints on the transmission and distribution system. Deregulation, capacity shortages, capital investment avoidance, reduced domestic power equipment availability, increasing electricity imports, and increasing environmental regulations will all influence the requirements for power regulation in the future. Traditionally, utilities have been interested in battery storage as an option to supply peak power through load leveling. Recently, other dynamic benefits of battery storage have been identified which potentially have equal or greater value to electric utilities. These benfits are power regulation functions including area regulation, area protection, spinning reserve, power factor correction, thermal unit minimum loading, and the ability to absorb qualifying facilities. The value of these benefits coupled with the ability to provide peak power will result in battery storage becoming an economically attractive option for utilities in the future. Lead-acid batteries-similar to those manufactured for automotive and industrial uses-are currently being marketed for utility applications. Compared to the traditional flooded-cell battery that regulates routine watering and maintenance, valve-regulated lead-acid (VRLA) batteries can meet many of the requirements of power regulation at significantly lower operating and maintenance costs. Advanced batteries, undergoing a worldwide research and development effort, are likely to emerge early in the next decade. Batteries such as sodium-sulfur and zinc-bromine offer the promise of even higher performance at lower cost. This paper presents an overview of future battery storage applications and technologies. Trends in the utility industry and the future role of battery storage will be addressed with an emphasis on power regulation options. Discussions on battery storage for specific power regulation applications are presented as well as the status of advanced battery development in Europe, Japan, and the United States.