Development update of the NAS battery

With the commercialization of the sodium-sulfur (NAS) battery in Japan by the Tokyo Electric Power Company (TEPCO) and NGK Insulators, Ltd. (NGK), and demonstration projects underway and under development in the US by the American Electric Power Company (AEP) and others, standard designs for high value target applications have been advancing. In particular, a reference peak shaving-based design has evolved that is well suited for leveling broad diurnal loads or cutting the narrower summer high peak loads for commercial buildings. In addition, standard designs for medium and high levels of power quality plus peak shaving applications have evolved, suitably for the Japanese and US markets, respectively. Over the past few years, TEPCO, AEP and NGK have been assessing their respective high value market applications for the NAS battery, developing related standard designs, conducting confirmatory testing for the standard modules and advancing plans for the broad deployment of the NAS battery. This paper provides an update of such NAS battery development and deployment status and plans.