American Electric Power (AEP), Columbus, Ohio, along with partners AEP EmTech, LLC (an AEP subsidiary), Tokyo Electric Power Co. (TEPCO), and NGK Insulators, Ltd. (NGK), will conduct the first U.S. demonstration to test the combined power quality and peak-shaving capabilities of the sodium sulfur (NAS) battery, an advanced electrical energy storage technology that promises improvements over conventional batteries. According to AEP, these advantages include higher efficiency, longer life cycle, higher energy density, reduced space requirements, and reduced maintenance costs. After finalizing the agreement in early December, the partnership expects the project to be in service by mid-2002 at an AEP office in suburban Columbus.
TEPCO and NGK have successfully developed, tested, and demonstrated the NAS battery in Japan for a broad range of applications. As a result, TEPCO will offer commercial NAS battery systems to their commercial and industrial customers, beginning in April 2002. Accordingly, NGK has committed to expand to a commercial-scale NAS battery production facility in Japan, with start-up projected for April 2003. The U.S. market for such applications of NAS battery systems should reach $250 to $300 million per year, based on a market study funded by AEP EmTech.
Officials of AEP EmTech and NGK signed a contract for NGK to supply two NAS battery modules that will provide up to 500kW of power quality protection for up to 5 min plus 100kW of peak-shaving capacity for up to 7 hr per day during peak power demand periods. AEP is also finalizing a separate contract with ABB, Inc., for the power electronics package that will integrate the DC battery installation with the AEP office building’s AC electrical system.
The AEP installation has been optimized to provide a high rating of power quality protection for modern office buildings’ sensitive electronic operations plus supply electrical load during peak load periods.
“With an NAS battery installation cited to serve a local peak load, you get a ‘distributed resource’ to replace some of the peak electricity from a central station generating plant and distribution system. By storing off-peak energy at night, this improves utilization of the utility’s generation and transmission and distribution assets and yields cost-effective premium power to the utility’s customers,” said Tom Shockley, AEP vice chairman and chief operating officer. “Such a distributed resource, we believe, has the potential for broad markets in the U.S. and other countries.”
AEP tested a 12.5kW NAS battery from February through November this year. “We put this battery through its paces at our Dolan Technology Center in Groveport, Ohio,” said John Harper, president of AEP EmTech. “We tested its ability to be discharged and recharged repeatedly, its ability to supply electrical load for over seven hours on peak, and its ability to supply uninterrupted high power during short-term power outages. The battery performed quite well.”