COLUMBUS, Ohio, Sept. 23, 2002 -
American Electric Power (NYSE: AEP) and a team of world-class partners dedicated the first U.S. stationary sodium sulfur (NAS®) battery today at an AEP office park here.
Partners in the project include NGK Insulators, Ltd. (NGK), Tokyo Electric Power Co. (TEPCO), ABB, the U.S. Department of Energy/Sandia National Laboratories and EPRI. The installation in suburban Gahanna will be operated for two years as a demonstration of the NAS battery, an advanced energy storage technology developed by TEPCO and NGK and being demonstrated at many sites throughout Japan.
ABB, Inc. of New Berlin, Wisc., supplied the power electronics package that integrates direct current (DC) from the NAS battery with the alternating current (AC) system in the office park. ABB’s office in Wisconsin is part of ABB, the global power and automation technology company.
Attending the dedication were representatives of the various partners and local elected officials and professional staff.
“The objective of this demonstration is to validate NAS operating characteristics in a real world application in the U.S., gain familiarity with the technology and develop needed economic models for its use. It is already widely demonstrated in Japan for peak shaving,” said John Harper, AEP vice president - technology development. “Ultimately, it is our expectation that the NAS technology will become a broadly accepted distributed resource that provides reliable energy storage capability and power quality mitigation.”
Cost of the demonstration project has not been disclosed.
NGK is on the verge of mass production of NAS battery modules. “As a result of our exhaustive work to advance sodium sulfur battery components and technology, we have passed the threshold of NAS commercialization in Japan,” said Eiji Hamamoto, managing director, NGK Insulators, Ltd. “We expect to start production at our commercial-scale manufacturing facility in the spring of 2003.”
“Since 1992, TEPCO and NGK have collaborated to demonstrate the practicality of sodium sulfur battery modules at various locations, loading conditions and climates,” said Sueharu Iwashina, director, general manager, R&D Center, TEPCO. “At this time, total installed NAS capacity in Japan is about 30 megawatts. This capacity, which is charged off peak, serves load without placing on-peak demands or stresses on conventional generating plants and the transmission and distribution system.” Because of the NAS battery’s high reliability, environmental friendliness and long backup power duration, a 2000kW system was selected for emergency power supply for the International Broadcasting Center at this year’s World Soccer Cup in Korea and Japan.
Prior to installing NAS units in Japan, TEPCO and NGK conducted extensive safety testing that included mishandling, dropping, exposure to fire, immersion in water and simulated seismic events.
“Sodium sulfur battery technology offers unique energy storage advantages where a relatively high peak load is required to mitigate power quality events,” said Chuck Clark, senior vice president of ABB, Inc. For this installation ABB chose a power conversion system derived from its ACS 600 drives product platform, combined with an ABB Industrial IT AC 800 controller that connects to the AEP system. This low-voltage technology, which closely matches the battery voltage, has been successfully applied by ABB for a wide range of power quality and distributed generation applications.
The NAS installation at Gahanna, in test operation since late August, contains two battery modules, each rated at 50 kilowatts (kW), that are capable of supplying 375 kilowatthours of energy. As such, the installation is rated at 100 kW for peak shaving or load leveling for about seven hours and up to 500 kW for short-term power quality mitigation. The batteries are expected to last 15 years or 2,500 full charge-discharge cycles. Because of its high energy density (it requires only one-third of the area needed by conventional lead acid batteries), it is relatively compact. The battery operates at about 85 percent DC efficiency due to the low resistance solid electrolyte developed by NGK.
While Ford Motor Company developed the basic principle in the 1960s and used sodium sulfur batteries in electric vehicles in the 1990s, it was NGK, a world-class developer and supplier of ceramics-based technology and products, that developed the key component of the NAS battery - a beta alumina electrolyte material that separates the positive sulfur and negative sodium electrodes. Ions of sodium shuttle back and forth between positive and negative electrodes depending on whether the battery is charging or discharging.
AEP tested and accumulated performance data for a 12.5-kW NAS battery at its Dolan Technology Center in Groveport, another Columbus suburb, during 2001. The battery was tested for its peak shaving ability, that is, the ability to store a charge off-peak and discharge the stored energy on peak to meet demand. In addition, the battery was put through staged power quality tests to determine its overload capability. The NAS battery provides increased reliability by supplying uninterrupted power during short-term fluctuations and interruptions. Depending on their capacity, NAS batteries can supply more than five times their nominal rating for up to 30 seconds. The batteries can supply lesser multiples of their capacity for longer periods, for example, four times capacity for 15 minutes. This flexibility allows a broad range of applications.
American Electric Power is a multinational energy company with a balanced portfolio of energy assets. AEP, the United States’ largest electricity generator, owns and operates more than 42,000 megawatts of generating capacity in the U.S. and select international markets. AEP is a leading wholesale energy marketer, ranking among North America’s top providers of wholesale power and natural gas with a growing wholesale presence in European markets. In addition to electricity generation, AEP owns and operates natural gas pipeline systems, natural gas storage, coal mines, and the fourth-largest inland barge company in the U.S. AEP is also one of the largest electric utilities in the United States, with almost 5 million customers linked to AEP’s wires. The company is based in Columbus, Ohio.
TEPCO, based in Tokyo, serves some 27 million customers in the metropolitan Tokyo area, making it the largest investor-owned electric utility in the world. TEPCO supplies approximately one-third of the electric demand in Japan. Its subsidiaries are engaged in fuel supply, property management, construction, telecommunications, information technology and environmental protection.
NGK Insulators Ltd., headquartered in Nagoya, Japan, is the world’s largest maker of electrical insulators. NGK produces ceramic insulators and other equipment for power transmission and distribution lines and substations, makes fine ceramic components for automobiles, printers and semiconductors and manufactures cast aluminum auto wheels. NGK’s engineering group designs and constructs water and sewage treatment systems.
ABB, headquartered in Zurich, Switzerland, is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impacts. ABB is a world leader in power electronics for electrical energy storage and has gained worldwide experience in successfully applying many technologies for energy storage. The ABB Group of companies operates in more than 100 countries and employs about 150,000 people.
Sandia National Labs, with headquarters in Albuquerque, New Mexico, conducts an Energy Storage System (ESS) program for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy. As part of its ESS program, Sandia will collect, analyze and disseminate NAS project data that are relevant to energy storage applications, systems and products. This effort is to increase the collective knowledge of energy storage systems, their operations, uses, benefits and potential issues. It is intended to accelerate the growth and maturation of the energy storage industry.
EPRI, based in Palo Alto, Calif., was founded in 1973 as a non-profit energy research consortium for utility members, their customers and society. EPRI provides science and technology-based solutions to its customers by managing a program of scientific research, technology development and product implementation. EPRI is the only science and technology consortium serving the entire energy industry - from energy conversion to end use - in every region of the world.