The world’s most powerful battery energy storage system (BESS) has completed its third year in operation. Operated since 2003 by Golden Valley Electric Association (GVEA) located in Fairbanks, Alaska. BESS has prevented more than 734,000 customer electrical outages while responding to 163 emergency events. GVEA serves 90,000 Alaskan residents spread over 2,000 square miles.
The area serviced by GVEA's BESS is considered an energy island geographic area served by electric systems that cannot be connected to large grid networks. Because of the extremely harsh weather conditions, back-up power is essential to stabilize the local electric grid and reduce its vulnerability to blackout events, which can literally be a matter of life and death in the below freezing Alaskan temperatures.
Several companies contributed to developing the BESS, including SAFT, the battery supplier; ABB, which provided the power conversion system; and Philadelphia Scientific (Philadelphia), a manufacturer of industrial battery components and accessories, which provided the battery watering system, deionization system and battery monitoring system.
The batteries were designed to maintain a four-year water reserve. However, when the watering process is required, the system must be temporarily taken offline. The watering must be done quickly, and if a single cell is missed, the entire system can fail. During tests, the Philadelphia Scientific single-point watering system, similar to the ones marketed for lift truck batteries, reliably filled each of the 13,760 battery cells in just 10 hours—six times faster than the next fastest watering system that was considered.
The monitoring system supplied by Philadelphia Scientific measures, records and reports the module voltage, string current, cell electrolyte level and cell internal temperature. Data collection and transfer are organized hierarchically with multiple devices dedicated to measuring and collecting data. Approximately 5,560 readings are taken every 30 seconds—a total of 5.8 billion readings per year. The data is analyzed and displayed through a central computer that forwards summary data to the human machine interface and is the main terminal for personnel who need to access the monitoring system.
The GVEA BESS demonstrates the long-term cost-efficiency and environmental benefits of this technology, underscoring the viability of battery energy storage as a reliable back-up power system for many electric utilities.
Source: Philadelphia Scientific
